JP2010148284A - Protective relay system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective relay system capable of reducing the number of current transformers and determining overload and short circuit and determining phase loss and disconnection in a three-element protective relay. <P>SOLUTION: The protective relay system includes: a cross through current transformer 11 in which an R-phase and an S-phase of a three-phase power supply line cross and penetrate through a circular core having a secondary coil wound therearound in a reverse direction and at an arbitrary angle; a current transformer 12 for gauge provided between the R-phase and a T-phase of the three-phase power supply line; and a three E relay 20 for detecting the generation of overload, short circuit, inverse phase, phase loss and disconnection in the three-phase power supply line based on a composite current I<SB>R-S</SB>inputted from the cross through current transformer 11 and a TR phase line voltage V<SB>TR</SB>inputted from the current transformer 12 for gauge. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、保護継電システムに関し、特に、三要素保護継電器を用いて三相交流回路における過負荷、短絡、反相、欠相および断線の発生を検出するのに好適な保護継電システムに関する。   The present invention relates to a protective relay system, and more particularly, to a protective relay system suitable for detecting occurrence of overload, short circuit, reverse phase, phase loss, and disconnection in a three-phase AC circuit using a three-element protective relay. .

従来、たとえば図４１に示すように、三要素保護継電器である三相誘導電動機用３Ｅリレー１１０（以下、「３Ｅリレー１１０」と称する。）は、三相電源線（三相交流回路）のＲ相、Ｓ相およびＴ相にそれぞれ設けられた第１乃至第３の変流器（ＣＴ）１₁〜１₃から入力されるＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの値と三相電源線に設けられた計器用変成器（ＶＴ）２から入力されるＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの値とに基づいて以下に示すようにして過負荷、反相および欠相を検出すると、三相電源線のＲ相、Ｓ相およびＴ相にそれぞれ設けられた第１乃至第３の遮断器３₁〜３₃を遮断するための第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。
（１）過負荷検出
Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの最大値が設定値以上であるか否か。
（２）反相検出
（ａ）電流反相検出タイプ：Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの値が設定値以下であるか否か。
（ｂ）電圧反相検出タイプ：Ｒ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの値が設定値以下であるか否か。
（３）欠相検出
Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの最小値が設定値以上であるか否か。 Conventionally, as shown in FIG. 41, for example, a 3E relay 110 for a three-phase induction motor (hereinafter referred to as “3E relay 110”), which is a three-element protective relay, is an R of a three-phase power line (three-phase AC circuit). R, S, and T phase currents I _R , I _S , I _T input from _first to _third current transformers (CT) 11 to ₁₃ provided in the phase, S phase, and T phase, respectively. And the values of the R-phase, S-phase, and T-phase voltages V _R , V _S , and V _T input from the instrument transformer (VT) 2 provided on the three-phase power line as shown below When overload, anti-phase, and open phase are detected, the _first to _third circuit breakers 3 ₁ to ₃ 3 provided in the R phase, S phase, and T phase of the three-phase power supply line are shut off. The first to third trip signals T _{1 to} T ₃ are output to the _first to _third circuit breakers 3 _{1 to} 3 ₃ , respectively.
(1) Overload detection Whether or not the maximum values of the R-phase, S-phase, and T-phase currents I _R , I _S , and I _T are equal to or greater than a set value.
(2) Anti-phase detection (a) Current anti-phase detection type: Whether the R-phase, S-phase, and T-phase currents I _R , I _S , I _T are less than or equal to the set value.
(B) Voltage anti-phase detection type: Whether or not the values of the R-phase, S-phase, and T-phase voltages V _R , V _S , and V _T are less than or equal to the set value.
(3) Missing phase detection Whether or not the minimum values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T are equal to or larger than the set value.

なお、下記の特許文献１には、三相交流入力を直流変換する機能を有した検出部を備え、検出部の出力の三相の平均実効値と過電流レベル整定回路の整定値を比較器で比較して過電流を判定するとともに、検出部の出力の三相の平均実効値と各相の実効値を３個の比較器で各々比較して欠相を判定する三相誘導電動機用２Ｅリレーにおいて、交流回路に高調波が含有し、そのピーク値が変動しても不要動作および動作遅延が起こらず、安定して動作できるようにするために、検出部を、熱電対を有し、周波数に関係無く交流入力の実効値に比例した直流起電力を得る熱電形変換器で構成した三相誘導電動機用２Ｅリレーが開示されている。
特開平９−２９８８３２号公報 The following Patent Document 1 includes a detector having a function of converting a three-phase alternating current input into a direct current, and compares the three-phase average effective value of the output of the detector with the set value of the overcurrent level settling circuit. 2E for the three-phase induction motor that determines the overcurrent by comparing the three-phase average effective value of the output of the detection unit and the effective value of each phase with three comparators. In the relay, harmonics are contained in the AC circuit, and unnecessary operation and operation delay do not occur even if the peak value fluctuates, so that the detection unit has a thermocouple, There is disclosed a 2E relay for a three-phase induction motor configured with a thermoelectric converter that obtains a DC electromotive force proportional to the effective value of the AC input regardless of the frequency.
Japanese Patent Application Laid-Open No. 9-299832

しかしながら、従来の３Ｅリレー１１０は、Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの値およびＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの値に基づいて過負荷、反相および欠相を検出しているので、変流器が３つ必要であるという問題と、過負荷および短絡を判別することができないとともに欠相および断線を判別することができないという問題とがあった。 However, the conventional 3E relay 110 is based on the values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _{T and} the values of the R-phase, S-phase, and T-phase voltages V _R , V _S , V _T. Since overload, anti-phase, and open phase are detected, the problem that three current transformers are necessary, overload and short circuit cannot be determined, and open phase and open circuit cannot be determined. There was a problem.

本発明の目的は、変流器の数を減らすことができるとともに、三要素保護継電器において過負荷および短絡の判別と欠相および断線の判別もすることができる保護継電システムを提供することにある。   An object of the present invention is to provide a protection relay system that can reduce the number of current transformers and can also determine overload and short circuit and phase loss and disconnection in a three-element protection relay. is there.

本発明の保護継電システムは、三相交流回路の第１および第２の相にそれぞれ流れる第１および第２の相電流（Ｉ_R，Ｉ_S）の差電流（Ｉ_R-S）と、該三相交流回路の１つの線間電圧（Ｖ_TR）または該三相交流回路の１つの線間電圧（Ｖ_TR）および１つの相電圧（Ｖ_T）または該三相交流回路の３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）とに基づいて、該三相交流回路における過負荷、短絡、反相、欠相および断線の発生を検出する三要素保護継電器（２０，５０，７０）を具備することを特徴とする。
ここで、２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（１１）と、
前記三相交流回路の前記第１および第３の相間に設けられた計器用変成器（１２）とをさらに具備し、前記三要素保護継電器（２０）が、前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）および位相変化角（Δθ_TR）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）とに基づいて、前記三相交流回路における反相、欠相および断線の発生を検出してもよい。
２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（４１）と、前記三相交流回路の前記第１および第３の相間に設けられた計器用変成器（４２）とをさらに具備し、前記三要素保護継電器（５０）が、前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）および位相変化角（Δθ_TR）と該計器用変成器から入力される１つの相電圧（Ｖ_T）の電圧変化率（Ｌ_T）および位相変化角（Δθ_T）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、前記合成電流の電流変化率と前記線間電圧の電圧変化率と前記相電圧の電圧変化率および位相差（β）とに基づいて、前記三相交流回路における反相の発生を検出し、前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）と該計器用変成器から入力される１つの相電圧（Ｖ_T）の電圧変化率（Ｌ_T）とに基づいて、前記三相交流回路における欠相および断線の発生を検出してもよい。
２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（６１）と、前記三相交流回路に設けられた計器用変成器（６２）とをさらに具備し、前記三要素保護継電器（７０）が、前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および２つの位相差（α_ST，α_TR）と前記計器用変成器から入力される３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）の電圧変化率（Ｌ_RS，Ｌ_ST，Ｌ_TR）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、前記合成電流の電流変化率と前記３つの線間電圧の電圧変化率と該３つの線間電圧のうちの１つの線間電圧の位相差（β_RS）とに基づいて、前記三相交流回路における反相の発生を検出し、前記合成電流の電流変化率および１つの位相差（α_TR）と前記３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）の電圧変化率（Ｌ_RS，Ｌ_ST，Ｌ_TR）および位相差（β_RS，β_ST，β_TR）とに基づいて、前記三相交流回路における欠相および断線の発生を検出してもよい。
前記合成電流の２つの位相差が、前記三相交流回路の前記第２および第３の相間の第２の線間電圧（Ｖ_ST）の位相（θ_ST）に対する該合成電流の位相差（α_ST）と、該三相交流回路の前記第３および第１の相間の第３の線間電圧（Ｖ_TR）の位相（θ_TR）に対する該合成電流の位相差（α_TR）とであり、前記３つの線間電圧の位相差が、前記第３の線間電圧（Ｖ_TR）の位相（θ_TR）に対する前記三相交流回路の前記第１および第２の相間の第１の線間電圧（Ｖ_RS）の位相差（β_RS）と、該第１の線間電圧（Ｖ_RS）の位相（θ_RS）に対する前記第２の線間電圧（Ｖ_ST）の位相差（β_ST）と、該第２の線間電圧（Ｖ_ST）の位相（θ_ST）に対する前記第３の線間電圧（Ｖ_TR）の位相差（β_TR）とであってもよい。 The protection relay system of the present invention includes a difference current (I _RS ) between first and second phase currents (I _R , I _S ) flowing in the first and second phases of a three-phase AC circuit, and the three One line voltage (V _TR ) of the phase AC circuit or one line voltage (V _TR ) and one phase voltage (V _T ) of the three-phase AC circuit or three line voltages of the three-phase AC circuit Based on (V _RS , V _ST , V _TR ), a three-element protection relay (20, 50, 70) for detecting occurrence of overload, short circuit, reverse phase, phase loss and disconnection in the three-phase AC circuit It is characterized by comprising.
Here, a cross-penetrating current transformer (11) in which the first and second phases of the three-phase AC circuit are crossed in an opposite direction and at an arbitrary angle through an annular core wound with a secondary coil. When,
An instrument transformer (12) provided between the first and third phases of the three-phase AC circuit, wherein the three-element protective relay (20) is input from the cross-through current transformer. The current change rate (K _RS ) and phase difference (α) of the combined current (I _RS ) and the voltage change rate (L _TR ) and phase of one line voltage (V _TR ) input from the instrument transformer Based on the change angle (Δθ _TR ), the occurrence of overload and short circuit in the three-phase AC circuit is detected, and the current change rate (K _RS ) of the combined current (I _RS ) input from the cross-through current transformer ) And phase difference (α) and the voltage change rate (L _TR ) of one line voltage (V _TR ) input from the instrument transformer, the anti-phase and phase loss in the three-phase AC circuit In addition, occurrence of disconnection may be detected.
A cross-penetrating current transformer (41) in which the first and second phases of the three-phase AC circuit are crossed in a reverse direction and at an arbitrary angle through an annular core around which a secondary coil is wound; And an instrument transformer (42) provided between the first and third phases of a three-phase AC circuit, and the three-element protective relay (50) is input from the cross-through current transformer. The current change rate (K _RS ) of the combined current (I _RS ), the voltage change rate (L _TR ) and the phase change angle (Δθ _TR ) of one line voltage (V _TR ) input from the instrument transformer Occurrence of overload and short circuit in the three-phase AC circuit based on the voltage change rate (L _T ) and phase change angle (Δθ _T ) of one phase voltage (V _T ) input from the instrument transformer Detecting the current change rate of the combined current, the voltage change rate of the line voltage, and the phase current. Based on the voltage change rate and the phase difference (β) of the voltage, occurrence of antiphase in the three-phase AC circuit is detected, and the current change rate of the combined current (I _RS ) input from the cross-through current transformer (K _RS ), phase difference (α), voltage change rate (L _TR ) of one line voltage (V _TR ) input from the instrument transformer, and one phase input from the instrument transformer based on the voltage change rate of the voltage (V _T) and (L _T), the occurrence of phase loss and breakage in the three-phase alternating current circuit may be detected.
A cross-penetrating current transformer (61) in which the first and second phases of the three-phase AC circuit are crossed in an opposite direction and at an arbitrary angle through an annular core around which a secondary coil is wound; An instrument transformer (62) provided in a three-phase AC circuit, and the three-element protection relay (70) is a current change of the combined current (I _RS ) input from the cross-through current transformer. Rate (K _RS ) and two phase differences (α _ST , α _TR ) and the voltage change rate (L _RS , V _TR ) of three line voltages (V _RS , V _ST , V _TR ) input from the instrument transformer. L _ST , L _TR ) to detect the occurrence of overload and short circuit in the three-phase AC circuit, the current change rate of the combined current, the voltage change rate of the three line voltages, and the three lines the phase difference between one of the line voltage of between voltage based on the (beta _RS), Contact to the three-phase alternating current circuit That detects the occurrence of a reverse phase, the current change rate of the combined current and one phase difference (alpha _TR) and the three line voltage _{(V RS, V ST, V} TR) rate of change of voltage (L _RS, Based on L _ST , L _TR ) and the phase difference (β _RS , β _ST , β _TR ), the occurrence of phase loss and disconnection in the three-phase AC circuit may be detected.
The two phase differences of the combined current are the phase difference (α of the combined current with respect to the phase (θ _ST ) of the second line voltage (V _ST ) between the second and third phases of the three-phase AC circuit. _ST ) and the phase difference (α _TR ) of the combined current with respect to the phase (θ _TR ) of the third line voltage (V _TR ) between the third and first phases of the three-phase AC circuit, A phase difference between the three line voltages is a first line voltage between the first and second phases of the three-phase AC circuit with respect to a phase (θ _TR ) of the third line voltage (V _TR ). (V _RS ) phase difference (β _RS ) and phase difference (β _ST ) of the second line voltage (V _ST ) with respect to the phase (θ _RS ) of the first line voltage (V _RS ) The phase difference (β _TR ) of the third line voltage (V _TR ) with respect to the phase (θ _ST ) of the second line voltage (V _ST ).

本発明の保護継電システムは、以下に示す効果を奏する。
（１）２次コイルを巻装した環状鉄心に三相交流回路の第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器を用いることにより、三相交流回路に設ける変流器の数を１つに減らすことができる。
（２）合成電流の電流変化率および位相差と、線間電圧および相電圧の電圧変化率および位相差とに基づいて、三相交流回路における過負荷および短絡の発生を検出することにより、三要素保護継電器において過負荷および短絡の判別をすることができる。
（３）合成電流の電流変化率および位相差と、線間電圧および相電圧の電圧変化率および位相差とに基づいて、三相交流回路における欠相および断線の発生を検出することにより、三要素保護継電器において三相交流回路における欠相および断線の判別をすることができる。 The protection relay system of the present invention has the following effects.
(1) By using a cross-through current transformer in which a first and second phases of a three-phase AC circuit are crossed in opposite directions and penetrated through an annular core around which a secondary coil is wound, The number of current transformers provided in the three-phase AC circuit can be reduced to one.
(2) Based on the current change rate and phase difference of the combined current and the voltage change rate and phase difference of the line voltage and the phase voltage, the occurrence of overload and short circuit in the three-phase AC circuit is detected. Overload and short circuit can be distinguished in the element protection relay.
(3) Based on the current change rate and phase difference of the combined current, and the voltage change rate and phase difference of the line voltage and phase voltage, the occurrence of phase loss and disconnection in the three-phase AC circuit is detected. In the element protection relay, it is possible to determine the phase loss and disconnection in the three-phase AC circuit.

上記の目的を、三要素保護継電器が、２次コイルを巻装した環状鉄心に三相交流回路の第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器から入力される合成電流の電流変化率および位相差と、三相交流回路の第１の相および第３の相間に設けられた計器用変成器から入力される１つの線間電圧の電圧変化率および位相変化角とに基づいて、三相交流回路における過負荷、短絡、反相、欠相および断線の発生を検出することにより実現した。   A cross penetration in which the three-element protective relay penetrates the first and second phases of the three-phase AC circuit in the opposite direction and at an arbitrary angle through an annular iron core wound with a secondary coil. The current change rate and phase difference of the combined current input from the current transformer, and one line voltage input from the instrument transformer provided between the first phase and the third phase of the three-phase AC circuit. Based on the voltage change rate and the phase change angle, it was realized by detecting the occurrence of overload, short circuit, reverse phase, open phase and disconnection in the three-phase AC circuit.

以下、本発明の保護継電システムの実施例について図面を参照して説明する。
まず、本発明の第１の実施例による保護継電システムについて、図１乃至図１６を参照して説明する。
本実施例による保護継電システムは、図１に示すように、三相電源線のＲ相およびＳ相がクロスするように貫通されたクロス貫通変流器１１と、三相電源線のＲ相とＴ相との間に設けられた計器用変成器１２と、クロス貫通変流器１１から入力される合成電流Ｉ_R-Sと計器用変成器１２から入力されるＴＲ相線間電圧Ｖ_TR（Ｔ相とＲ相との間の線間電圧）とに基づいて三相電源線における過負荷、短絡、反相、欠相および断線を検出する三相誘導電動機用３Ｅリレー２０（以下、「３Ｅリレー２０」と称する。）とを具備する。 Embodiments of the protective relay system of the present invention will be described below with reference to the drawings.
First, a protection relay system according to a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the protection relay system according to the present embodiment includes a cross-through current transformer 11 that is penetrated so that the R phase and the S phase of the three-phase power supply line cross, and the R phase of the three-phase power supply line. Instrument transformer 12 provided between the T phase and the T phase, the combined current I _RS inputted from the cross-through current transformer 11 and the TR phase line voltage V _TR (T 3E relay 20 for a three-phase induction motor (hereinafter referred to as “3E relay”) that detects an overload, a short circuit, an opposite phase, an open phase, and a disconnection in a three-phase power source line based on the line voltage between the phase and the R phase) 20 ”).

ここで、クロス貫通変流器１１は、２次コイルを巻装した環状鉄心に三相電源線のＲ相およびＳ相を逆向きにかつ任意の角度でクロスさせて貫通させた貫通形変流器である。
すなわち、三相電源線のＲ相はクロス貫通変流器１１の極性方向（環状鉄心の第１の開口面から環状鉄心の第２の開口面への方向）に貫通されているが、三相電源線のＳ相はクロス貫通変流器１１の反極性方向（環状鉄心の第２の開口面から環状鉄心の第１の開口面への方向）に貫通されている。
したがって、正常時におけるＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_T並びに合成電流Ｉ_R-SをＩ_R0，Ｉ_S0，Ｉ_T0およびＩ_(R-S)0で表すと、Ｒ相電流Ｉ_R0およびＳ相電流Ｉ_S0は図２（ａ）に示すように１２０°の位相差でクロス貫通変流器１１の環状鉄心を逆向きに貫通して流れる（すなわち、Ｒ相電流Ｉ_R0はクロス貫通変流器１１の環状鉄心を極性方向に貫通して流れ、Ｓ相電流Ｉ_S0はクロス貫通変流器１１の環状鉄心を反極性方向に貫通して流れる）ため、クロス貫通変流器１１から３Ｅリレー２０に入力される合成電流Ｉ_(R-S)0はＲ相電流Ｉ_R0とＳ相電流Ｉ_S0との差電流（ベクトル差）となり、合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜はＲ相電流Ｉ_R0の値｜Ｉ_R0｜（Ｓ相電流Ｉ_S0の値｜Ｉ_S0｜）の３^1/2倍となり、合成電流Ｉ_(R-S)0の位相θ_(R-S)0は２７０°となる。
Ｉ_(R-S)0＝Ｉ_R0−Ｉ_S0
｜Ｉ_(R-S)0｜＝｜Ｉ_R0−Ｉ_S0｜＝３^1/2×｜Ｉ_R0｜（＝３^1/2×｜Ｉ_S0｜）
θ_(R-S)0＝２７０° Here, the cross-through current transformer 11 is a through-type current transformer in which an R-phase and an S-phase of a three-phase power supply line are crossed in an opposite direction and at an arbitrary angle through an annular core wound with a secondary coil. It is a vessel.
That is, the R phase of the three-phase power supply line is penetrated in the polarity direction of the cross-through current transformer 11 (direction from the first opening surface of the annular core to the second opening surface of the annular core). The S phase of the power supply line is penetrated in the opposite polarity direction of the cross through current transformer 11 (direction from the second opening surface of the annular core to the first opening surface of the annular core).
Therefore, when the R-phase, S-phase and T-phase currents I _R , I _S , I _{T and the} combined current I _RS in the normal state are expressed by I _R0 , I _S0 , I _T0 and I _{(RS) 0} , the R-phase current I _As shown in FIG. 2A, _R0 and S-phase current I _S0 flow through the annular core of cross-through current transformer 11 in the opposite direction with a phase difference of 120 ° (that is, R-phase current I _R0 is crossed). Since the annular iron core of the through current transformer 11 flows in the polarity direction and the S-phase current I _S0 flows through the annular iron core of the cross current transformer 11 in the opposite polarity), the cross current transformer 11 combined current is input to 3E relay 20 from I _{(RS) 0} is the difference between the R-phase current I _R0 and S-phase current I _S0 current (vector difference), and the combined current I _{(RS) 0} value | I _{(RS ) 0} | the value of R-phase current I _R0 | I _R0 | (the value of S-phase current I _S0 | I _S0 | becomes ^31/2 times), the phase theta _{(RS) 0} of the combined current I _{(RS) 0} Is 2 0 a °.
I _{(RS) 0} = I _R0 -I _S0
| I _{(RS) 0} | = | I _R0 −I _S0 | = 3 ^1/2 × | I _R0 | (= 3 ^1/2 × | I _S0 |)
θ _{(RS) 0} = 270 °

また、正常時におけるＲ相電圧Ｖ_RおよびＴ相電圧Ｖ_TをＶ_R0およびＶ_T0で表すと、Ｒ相電圧Ｖ_R0およびＴ相電圧Ｖ_T0は図２（ｂ）に示すように２４０°の位相差であるため、計器用変成器１２から３Ｅリレー２０に入力されるＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜はＴ相電圧Ｖ_T0の値｜Ｖ_T0｜（Ｒ相電圧Ｖ_R0の値｜Ｖ_R0｜）の３^1/2倍となり、ＴＲ相線間電圧Ｖ_TR0の位相θ_TR0は２１０°となる。
Ｖ_TR0＝Ｖ_T0−Ｖ_R0
｜Ｖ_TR0｜＝｜Ｖ_T0−Ｖ_R0｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×｜Ｖ_R0｜
θ_TR0＝２１０° Further, when the R-phase voltage V _R and the T-phase voltage V _T at the normal time are expressed by V _R0 and V _T0 , the R-phase voltage V _R0 and the T-phase voltage V _T0 are 240 ° as shown in FIG. Because of the phase difference, the value | V _TR0 | of the TR phase line voltage V _TR0 input to the 3E relay 20 from the instrument transformer 12 is the value of the T phase voltage V _T0 | V _T0 | (R phase voltage V _R0 value | V _R0 |) of 3 to ^1/2 times, the phase theta _TR0 of TR-phase line voltage V _TR0 becomes 210 °.
V _TR0 = V _T0 -V _R0
| V _TR0 | = | V _T0 −V _R0 | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × | V _R0 |
θ _TR0 = 210 °

３Ｅリレー２０は、クロス貫通変流器１１から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sおよび位相差α（ＴＲ相線間電圧Ｖ_TRの位相θ_TRに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）と計器用変成器１２から入力されるＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRおよび位相変化角（Δθ_TR）とに基づいて過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡を検出する。
また、３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sおよび位相差αとＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRとに基づいてＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相を検出する。
さらに、３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sおよび位相差αとＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRとに基づいて、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線を検出するとともに、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出する。
３Ｅリレー２０は、以上のようにして過負荷などを検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The 3E relay 20 is a current change rate K _RS and a phase difference α (the phase difference with respect to the phase θ _TR of the TR phase line voltage V _TR) of the combined current I _RS input from the cross-through current transformer 11, and the delay phase is Based on the positive value, the lead phase is indicated by a negative value (the same applies hereinafter) and the voltage change rate L _TR and the phase change angle (Δθ _TR ) of the TR phase line voltage V _TR input from the instrument transformer 12. Overload, R-S phase short circuit, S-T phase short circuit, T-R phase short circuit and three-phase short circuit are detected.
Further, 3E relay 20, the composite current I _RS of the current rate of change K _RS and the phase difference α and TR-phase line voltage V _TR RS reciprocal phase based on the voltage change rate L _TR of, S-T-reciprocal phase And TR reciprocal phase is detected.
Furthermore, 3E relay 20, the composite current I _RS on the basis of the voltage change rate L _TR of the current rate of change K _RS and the phase difference α and TR-phase line voltage V _TR of, R in the star-connected three-phase power supply line Detects phase open phase, S phase open phase, T phase open phase, R phase open wire, S phase open wire and T phase open wire, as well as R phase open phase, S phase open phase, T Phase open phase, RS phase disconnection, ST phase disconnection and TR phase disconnection are detected.
When the 3E relay 20 detects an overload or the like as described above, the 3E relay 20 outputs the first to third trip signals T _{1 to} T ₃ to the first to third circuit breakers 3 _{1 to} 3 ₃ , respectively.

次に、３Ｅリレー２０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について、図３乃至図５を参照して詳しく説明する。
なお、以下では、説明の簡単のために、Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値を“１”とし、Ｒ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値を“１”とする。また、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0の値をＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値（すなわち、｜Ｉ_R0｜＝｜Ｉ_S0｜＝｜Ｉ_T0｜＝１）とし、正常時のＲ相、Ｓ相およびＴ相電圧Ｖ_R0，Ｖ_S0，Ｖ_T0の値をＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値（すなわち、｜Ｖ_R0｜＝｜Ｖ_S0｜＝｜Ｖ_T0｜＝１）とし、正常時のＲ相電流Ｉ_R0の位相θ_R0を０°とする。さらに、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出値を定格電流の１１５％以上とする。 Next, a method for detecting overload, R-S phase short circuit, S-T phase short circuit, T-R phase short circuit, and three-phase short circuit in the 3E relay 20 will be described in detail with reference to FIGS.
In the following, for simplicity of explanation, the rated current values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T are set to “1”, and the R-phase, S-phase, and T-phase voltages V _R , V _S , V _T rated voltage value is “1”. Further, the values of the R-phase, S-phase and T-phase currents I _R0 , I _S0 and I _{T0 in} the normal state are changed to the rated current values of the R-phase, S-phase and T-phase currents I _R , I _S and I _T (that is, | I _R0 | = | I _S0 | = | I _T0 | = 1), and the values of the R phase, S phase, and T phase voltages V _R0 , V _S0 , and V _T0 in the normal state are the R phase, S phase, and T phase voltages. V _R, V _S, the rated voltage value of V _{T (i.e., | V R0 | = | V} S0 | = | V T0 | = 1) and then, with the phase theta _R0 of the normal time of R-phase current I _R0 0 ° To do. Furthermore, the detected value of overload, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit is set to 115% or more of the rated current.

（１）正常時の合成電流Ｉ_(R-S)0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは（１−１）式から（１−５）式でそれぞれ表される（図２（ａ），（ｂ）参照）。
｜Ｉ_(R-S)0｜＝｜Ｉ_R0−Ｉ_S0｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１＝３^1/2 （１−１）
θ_(R-S)0＝３３０° （１−２）
｜Ｖ_TR0｜＝｜Ｖ_T0−Ｖ_R0｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１＝３^1/2 （１−３）
θ_TR0＝２１０° （１−４）
α₀＝θ_(R-S)0−θ_TR0＝３３０°−２１０°＝１２０° （１−５） (1) Combined current I _{(RS) 0} and TR phase line voltage V _TR0 at normal time
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the equations (1-1) to (1-5) (see FIGS. 2A and 2B).
| I _{(RS) 0} | = | I _R0 −I _S0 | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1 = 3 ^1/2 (1-1)
θ _{(RS) 0} = 330 ° (1-2)
| V _TR0 | = | V _T0 −V _R0 | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1 = 3 ^1/2 (1-3)
θ _TR0 = 210 ° (1-4)
α ₀ = θ _{(RS) 0} −θ _TR0 = 330 ° -210 ° = 120 ° (1-5)

（２）過負荷時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
過負荷が発生して定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tが三相電源線のＲ相、Ｓ相およびＴ相にそれぞれ流れたとすると、過負荷時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRとは（２−１）式から（２−７）式でそれぞれ表される（図３（ａ），（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×（１．１５×｜Ｉ_R0｜）
＝３^1/2×（１．１５×１）＝３^1/2×１．１５ （２−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2×１．１５）／３^1/2
＝１．１５ （２−２）
θ_R-S＝３３０° （２−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （２−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （２−５）
θ_TR＝２１０° （２−６）
Δθ_TR＝θ_TR−θ_TR0＝２１０°−２１０°＝０° （２−７） (2) Combined current I _RS and TR phase line voltage V _TR during overload
R-phase, S-phase, and T-phase currents that are 1.15 times the rated current values (in this example, normal R-phase, S-phase, and T-phase currents I _R0 , I _S0 , I _T0 ) due to overload I _R, I _S, R-phase of the I _T is a three-phase power line, assuming that respectively flow into S phase and T-phase, the value of the composite current I _RS during overload | I _RS |, the current change rate K _RS and phase The values of θ _RS and TR phase line voltage V _TR | V _TR |, voltage change rate L _TR , phase θ _TR and phase change angle Δθ _TR are expressed by equations (2-1) to (2-7), respectively. (See FIGS. 3A and 3B).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × (1.15 × | I _R0 |)
= 3 ^1/2 × (1.15 × 1) = 3 ^1/2 × 1.15 (2-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 × 1.15) / 3 ^1/2
= 1.15 (2-2)
θ _RS = 330 ° (2-3)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (2-4)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (2-5)
θ _TR = 210 ° (2-6)
Δθ _TR = θ _TR −θ _TR0 = 210 ° −210 ° = 0 ° (2-7)

（３）Ｒ−Ｓ相短絡時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
Ｒ相−Ｓ相間の短絡事故（Ｒ−Ｓ相短絡）が発生すると、三相電源線のＲ相およびＳ相にＲ相事故電流Ｉ_FRおよびＳ相事故電流Ｉ_FSが逆方向に流れるが、三相電源線のＴ相には正常時のＴ相電流Ｉ_T0が流れたままとなる。
したがって、定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相およびＳ相事故電流Ｉ_FR，Ｉ_FSが流れたとすると、Ｒ−Ｓ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは（３−１）式から（３−８）式でそれぞれ表される（図４（ａ−１），（ａ−２）参照）。なお、Ｒ相、Ｓ相およびＴ相事故電流Ｉ_FR，Ｉ_FS，Ｉ_FTのインピーダンス角θ＝７５°とする。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_FS｜＝２×｜Ｉ_FR｜＝２×（１．１５×｜Ｉ_R0｜）
＝２×（１．１５×１）＝２．３ （３−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（２．３）／３^1/2（＝１．３２８） （３−２）
θ_R-S＝４５° （３−３）
｜Ｖ_TR｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （３−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （３−５）
θ_TR＝２１５．２° （３−６）
Δθ_TR＝θ_TR−θ_TR0＝２１５．２°−２１０°＝５．２° （３−７）
α＝θ_R-S−θ_TR＝４５°−２１５．２°＝−１７０．２° （３−８） (3) Composite current I _RS and TR phase line voltage V _TR when _RS phase is short-circuited
When a short-circuit accident between R-phase and S-phase (R-S-phase short-circuit) occurs, R-phase fault current I _FR and S-phase fault current I _FS flow in opposite directions in the R-phase and S-phase of the three-phase power line. A normal T-phase current I _T0 still flows in the T-phase of the three-phase power line.
Therefore, the R-phase and S-phase fault currents I _FR and I _FS are 1.15 times the rated current value (in this example, the normal R-phase, S-phase and T-phase currents I _R0 , I _S0 and I _T0 ). Assuming that the current flows, the value of the combined current I _RS when the _RS phase is short-circuited | I _RS |, the current change rate K _RS and the value of the phase θ _RS and the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR , phase θ _TR, phase change angle Δθ _TR and phase difference α of combined current I _RS are expressed by equations (3-1) to (3-8), respectively (FIGS. 4A-1 and 4A-1). a-2)). It is assumed that the impedance angle θ of the R-phase, S-phase, and T-phase fault currents I _FR , I _FS , and I _FT is 75 °.
| I _RS | = | I _FR −I _FS | = 2 × | I _FR | = 2 × (1.15 × | I _R0 |)
= 2 × (1.15 × 1) = 2.3 (3-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (2.3) / 3 ^1/2 (= 1.328) (3-2)
θ _RS = 45 ° (3-3)
| V _TR | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (3-4)
L _TR = | V _TR | / | V _TR0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (3-5)
θ _TR = 215.2 ° (3-6)
Δθ _TR = θ _TR −θ _TR0 = 215.2 ° -210 ° = 5.2 ° (3-7)
α = θ _RS −θ _TR = 45 ° -215.2 ° = −170.2 ° (3-8)

（４）Ｓ−Ｔ相短絡時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
Ｓ相−Ｔ相間の短絡事故（Ｓ−Ｔ相短絡）が発生すると、三相電源線のＳ相およびＴ相にＳ相事故電流Ｉ_FSおよびＴ相事故電流Ｉ_FTが逆方向に流れるが、三相電源線のＲ相には正常時のＲ相電流Ｉ_R0が流れたままとなる。
したがって、定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは（４−１）式から（４−８）式でそれぞれ表される（図４（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R0−Ｉ_FS｜＝｜Ｉ_R0−１．１５Ｉ_S0｜
＝（｜Ｉ_R0｜²＋｜１．１５Ｉ_S0｜²−２×｜Ｉ_R0｜×｜１．１５Ｉ_S0｜×ｃｏｓ１６５°）^1/2
＝（１²＋１．１５²−２×１×１．１５×ｃｏｓ１６５°）^1/2
＝２．１３２ （４−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝２．１３２／３^1/2＝１．２３１ （４−２）
θ_R-S＝３５３° （４−３）
｜Ｖ_TR｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４−５）
θ_TR＝２０４．８° （４−６）
Δθ_TR＝θ_TR−θ_TR0＝２０４．８°−２１０°＝−５．２° （４−７）
α＝θ_R-S−θ_TR＝３５３°−２０４．８°＝１４８．２° （４−８）
また、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-Sの位相差αとは（４−９）式から（４−１２）式でそれぞれ表される（図４（ｂ）の一点鎖線参照）。
｜Ｉ_R-S｜＝｜−Ｉ_FS｜≫｜１．１５Ｉ_S0｜≫１．１５ （４−９）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜≫１．１５／３^1/2（＝０．６６４） （４−１０）
θ_R-S＝３４５° （４−１１）
α＝θ_R-S−θ_TR＝３４５°−２０４．８°＝１４０．２° （４−１２） (4) Composite current I _RS and TR phase line voltage V _TR when S-T phase is short-circuited
When a short-circuit accident between S-phase and T-phase (S-T phase short-circuit) occurs, S-phase fault current _IFS and T-phase fault current _IFT flow in the opposite directions in the S-phase and T-phase of the three-phase power line. The normal R-phase current I _R0 still flows in the R-phase of the three-phase power line.
Therefore, the S-phase and T-phase fault currents I _FS and I _FT are 1.15 times the rated current value (in this example, the normal R-phase, S-phase and T-phase currents I _R0 , I _S0 and I _T0 ). If the current flows, the value of the combined current I _RS at the time of the S-T phase short circuit | I _RS |, the current change rate K _RS and the value of the phase θ _RS and the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR , phase θ _TR, phase change angle Δθ _TR and phase difference α of combined current I _RS are expressed by equations (4-1) to (4-8), respectively (FIG. 4 (b-1), ( b-2)).
| I _RS | = | I _R0 −I _FS | = | I _R0 −1.15I _S0 |
= (| I _R0 | ² + | 1.15I _S0 | ² −2 × | I _R0 | × | 1.15I _S0 | × cos 165 °) ^1/2
= (1 ² +1.15 ² -2 × 1 × 1.15 × cos 165 °) ^1/2
= 2.132 (4-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 2.132 / 3 ^1/2 = 1.231 (4-2)
θ _RS = 353 ° (4-3)
| V _TR | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (4-4)
L _TR = | V _TR | / | V _TR0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (4-5)
θ _TR = 204.8 ° (4-6)
Δθ _TR = θ _TR −θ _TR0 = 204.8 ° −210 ° = −5.2 ° (4-7)
α = θ _RS −θ _TR = 353 ° −204.8 ° = 148.2 ° (4-8)
Also, assuming that the S-phase and T-phase fault currents I _FS and I _{FT exceeding} the rated current value flow, the value of the combined current I _RS at the time of the S-T phase short circuit | I _RS |, the current change rate K _RS and The phase difference α between the phase θ _RS and the combined current I _RS is expressed by the equations (4-9) to (4-12), respectively (see the dashed line in FIG. 4B).
| I _RS | = | −I _FS | >> | 1.15I _S0 | >> 1.15 (4-9)
K _RS = | I _RS | / | I _{(RS) 0} | >> 1.15 / 3 ^1/2 (= 0.664) (4-10)
θ _RS = 345 ° (4-11)
α = θ _RS −θ _TR = 345 ° −204.8 ° = 140.2 ° (4-12)

（５）Ｔ−Ｒ相短絡時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
Ｔ相−Ｒ相間の短絡事故（Ｔ−Ｒ相短絡）が発生すると、三相電源線のＴ相およびＲ相にＴ相事故電流Ｉ_FTおよびＲ相事故電流Ｉ_FRが逆方向に流れるが、三相電源線のＳ相には正常時のＳ相電流Ｉ_S0が流れたままとなる。
したがって、定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは（５−１）式から（５−８）式でそれぞれ表される（図５（ａ−１），（ａ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_S0｜＝｜１．１５Ｉ_R0−Ｉ_S0｜
＝（｜１．１５Ｉ_R0｜²＋｜Ｉ_S0｜²−２×｜１．１５Ｉ_R0｜×｜Ｉ_S0｜×ｃｏｓ１５°）^1/2
＝（１．１５²＋１²−２×１．１５×１×ｃｏｓ１５°）^1/2
＝０．３１８ （５−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝０．３１８／３^1/2＝０．１８３ （５−２）
θ_R-S＝５０．４° （５−３）
｜Ｖ_TR｜＝０．８×３^1/2 （５−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（０．８×３^1/2）／３^1/2＝０．８ （５−５）
θ_TR＝２１０° （５−６）
Δθ_TR＝θ_TR−θ_TR0＝２１０°−２１０°＝０° （５−７）
α＝θ_R-S−θ_TR＝５０．４°−２１０°＝−１５９．６° （５−８）
また、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-Sの位相差αとは（５−９）式から（５−１２）式でそれぞれ表される（図４（ｃ）の一点鎖線参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR｜≫１．１５×｜Ｉ_R0｜≫１．１５ （５−９）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜≫１．１５／３^1/2（＝０．６６４） （５−１０）
θ_R-S＝１０５° （５−１１）
α＝θ_R-S−θ_TR＝１０５°−２１０°＝−１０５° （５−１２） (5) Composite current I _RS and TR phase line voltage V _TR when T-R phase is short-circuited
When a short-circuit accident between T-phase and R-phase (T-R phase short-circuit) occurs, T-phase fault current I _FT and R-phase fault current I _FR flow in opposite directions in T-phase and R-phase of the three-phase power line. The normal S-phase current I _S0 still flows through the S-phase of the three-phase power supply line.
Therefore, the T-phase and R-phase fault currents I _FT and I _FR are 1.15 times the rated current value (in this example, normal R-phase, S-phase and T-phase currents I _R0 , I _S0 , I _T0 ). If the current flows, the value of the combined current I _RS at the time of the TR phase short circuit | I _RS |, the current change rate K _RS and the value of the phase θ _RS and the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR , phase θ _TR, phase change angle Δθ _TR, and phase difference α of combined current I _RS are expressed by equations (5-1) to (5-8), respectively (FIGS. 5A-1 and 5A). a-2)).
| I _RS | = | I _FR −I _S0 | = | 1.15 I _R0 −I _S0 |
= (| 1.15I _R0 | ² + | I _S0 | ² −2 × | 1.15I _R0 | × | I _S0 | × cos 15 °) ^1/2
= (1.15 ² +1 ² -2 × 1.15 × 1 × cos 15 °) ^1/2
= 0.318 (5-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 0.318 / 3 ^1/2 = 0.183 (5-2)
θ _RS = 50.4 ° (5-3)
| V _TR | = 0.8 × 3 ^1/2 (5-4)
L _TR = | V _TR | / | V _TR0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (5-5)
θ _TR = 210 ° (5-6)
Δθ _TR = θ _TR −θ _TR0 = 210 ° −210 ° = 0 ° (5-7)
_{α = θ RS -θ TR = 50.4} ° -210 ° = -159.6 ° (5-8)
Also, assuming that the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow, the value of the combined current I _RS when the TR phase is short-circuited | I _RS |, the current change rate K _RS and The phase difference α between the phase θ _RS and the combined current I _RS is expressed by the equations (5-9) to (5-12) (see the dashed line in FIG. 4C).
| I _RS | = | I _FR | >> 1.15 × | I _R0 | >> 1.15 (5-9)
K _RS = | I _RS | / | I _{(RS) 0} | >> 1.15 / 3 ^1/2 (= 0.664) (5-10)
θ _RS = 105 ° (5-11)
α = θ _RS −θ _TR = 105 ° −210 ° = −105 ° (5-12)

（６）三相短絡時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相短絡事故（三相短絡）が発生すると、三相電源線のＲ相、Ｓ相およびＴ相にＲ相事故電流Ｉ_FR、Ｓ相事故電流Ｉ_FSおよびＴ相事故電流Ｉ_FTが位相差１２０°でそれぞれ流れる。
したがって、定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相事故電流Ｉ_FR，Ｉ_FS，Ｉ_FTが流れたとすると、三相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは（６−１）式から（６−８）式でそれぞれ表される（図５（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_FS｜＝３^1/2×｜Ｉ_FR｜＝３^1/2×（｜１．１５Ｉ_R0｜）
＝３^1/2×（１．１５×１）＝３^1/2×１．１５
（＝１．９９２） （６−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2×１．１５）／３^1/2
＝１．１５ （６−２）
θ_R-S＝４５° （６−３）
｜Ｖ_TR｜＝０．８×３^1/2 （６−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（０．８×３^1/2）／３^1/2＝０．８ （６−５）
θ_TR＝２１０° （６−６）
Δθ_TR＝θ_TR−θ_TR0＝２１０°−２１０°＝０° （６−７）
α＝θ_R-S−θ_TR＝４５°−２１０°＝−１６５° （６−８） (6) Combined current I _RS and TR phase line voltage V _TR during three-phase short circuit
When a three-phase short-circuit accident (three-phase short-circuit) occurs, the R-phase fault current I _FR , the S-phase fault current I _FS and the T-phase fault current I _FT are phase-differences in the R-phase, S-phase and T-phase Each flows at 120 °.
Therefore, the R-phase, S-phase, and T-phase fault currents I _FR , 1.15 times the rated current value (in this example, normal R-phase, S-phase, and T-phase currents I _R0 , I _S0 , I _T0 ) If I _FS and I _FT flow, the value of the combined current I _RS at the time of a three-phase short circuit | I _RS |, the current change rate K _RS and the value of the phase θ _RS and the TR phase line voltage V _TR | V _TR | The voltage change rate L _TR , the phase θ _{TR, the} phase change angle Δθ _TR, and the phase difference α of the combined current I _RS are expressed by equations (6-1) to (6-8), respectively (FIG. 5 (b- 1) and (b-2)).
| I _RS | = | I _FR −I _FS | = 3 ^1/2 × | I _FR | = 3 ^1/2 × (| 1.15I _R0 |)
= 3 ^1/2 × (1.15 × 1) = 3 ^1/2 × 1.15
(= 1.992) (6-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 × 1.15) / 3 ^1/2
= 1.15 (6-2)
θ _RS = 45 ° (6-3)
| V _TR | = 0.8 × 3 ^1/2 (6-4)
L _TR = | V _TR | / | V _TR0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (6-5)
θ _TR = 210 ° (6-6)
Δθ _TR = θ _TR −θ _TR0 = 210 ° −210 ° = 0 ° (6-7)
α = θ _RS −θ _TR = 45 ° −210 ° = −165 ° (6-8)

（７）過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出
合成電流Ｉ_R-Sの位相θ_R-Sがアーク抵抗の影響により−４５°〜１５°の範囲で変動することを考慮する。
（ａ）過負荷の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が所定の過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が所定の第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）よりも大きいと、「過負荷が発生した」と判定する。
（ｂ）Ｒ−Ｓ相短絡の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．３２８）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で所定の第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝５．２°）が第１の過負荷・短絡検出位相変化角範囲（たとえば、５．２°〜３０°（短絡点までのインピーダンスを考慮））内の値であると、「Ｒ−Ｓ相短絡が発生した」と判定する。
（ｃ）Ｓ−Ｔ相短絡の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．２３１）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝−５．２°）が第２の過負荷・短絡検出位相変化角範囲（たとえば、−５．２°〜−３０°（短絡点までのインピーダンスを考慮））内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
また、３Ｅリレー２０は、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であっても、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．９５４）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下であり、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝−５．２°）が第２の過負荷・短絡検出位相変化角範囲（たとえば、−５．２°〜−３０°）内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
（ｄ）Ｔ−Ｒ相短絡の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．１８３）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-Sの位相差α（＝−１５９．６°）が所定の第１の過負荷・短絡検出位相差範囲（たとえば、−２０３°〜−９０°）内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する。
また、３Ｅリレー２０は、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であっても、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-Sの位相差（＝−１０５°）が第２の過負荷・短絡検出位相差範囲（たとえば、−２１０°〜−１５０°）内の値でないと、「Ｔ−Ｒ相短絡が発生した」と判定する。
（ｅ）三相短絡の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-Sの位相差（＝−１６５°）が第２の過負荷・短絡検出位相差範囲（たとえば、−２１０°〜−１５０°）内の値であると、「三相短絡が発生した」と判定する。 (7) overload, RS-phase short circuit, S-T phase short-circuit, T-R phase short-circuit and three-phase short circuit detecting the resultant current I _RS phase theta _RS is -45 ° to 15 ° due to the influence of the arc resistance Consider fluctuations in range.
(A) Overload detection In the 3E relay 20, the current change rate K _RS (= 1.15) of the combined current I _RS is equal to or greater than a predetermined overload / short-circuit detection current change rate value (eg, 1.15). When the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is larger than a predetermined first overload / short-circuit detection voltage change rate value (for example, 0.96), Is determined to occur.
(B) Detection of R-S phase short circuit The 3E relay 20 has a current change rate K _RS (= 1.328) of the combined current I _RS that is equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15). Yes, and the voltage change rate L _TR (= 0.954) of the TR phase line voltage V _TR is equal to or less than a first overload / short-circuit detection voltage change rate value (for example, 0.96) The overload / short circuit detection voltage change rate value (for example, 0.8) is larger and the phase change angle Δθ _TR (= 5.2 °) of the TR phase line voltage V _TR is the first overload / short circuit. If it is a value within the detection phase change angle range (for example, 5.2 ° to 30 ° (considering impedance to the short circuit point)), it is determined that “the R-S phase short circuit has occurred”.
(C) Detection of S-T phase short circuit The 3E relay 20 has a current change rate K _RS (= 1.231) of the combined current I _RS equal to or higher than an overload / short circuit detection current change rate value (eg, 1.15). And the second overload when the voltage change rate L _TR (= 0.954) of the TR phase line voltage V _TR is equal to or less than the first overload / short-circuit detection voltage change rate value (for example, 0.96). The phase change angle Δθ _TR (= −5.2 °) of the TR phase line voltage V _TR is greater than the short circuit detection voltage change rate value (for example, 0.8), and the second overload / short circuit detection. If the value is within a phase change angle range (for example, -5.2 ° to -30 ° (considering impedance to the short-circuit point)), it is determined that “S-T phase short-circuit has occurred”.
Further, the 3E relay 20 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the S-phase and T-phase fault currents I _FS and I _FT exceeding the rated current value flow. Is less than the overload / short-circuit detection current change rate value (for example, 1.15), the voltage change rate L _TR (= 0.954) of the TR phase line voltage V _TR is the second overload / short-circuit value. Phase change of TR phase-to-line voltage V _TR that is greater than the detected voltage change rate value (eg, 0.8) and less than or equal to the first overload / short-circuit detected voltage change rate value (eg, 0.96) When the angle Δθ _TR (= −5.2 °) is a value within the second overload / short-circuit detection phase change angle range (for example, −5.2 ° to −30 °), “ST phase short circuit” Is determined to occur.
(D) Detection of TR phase short circuit The 3E relay 20 has a current change rate K _RS (= 0.183) of the combined current I _RS that is less than an overload / short circuit detection current change rate value (eg, 1.15). Yes, and the voltage change rate L _TR (= 0.8) of the TR phase line voltage V _TR is equal to or less than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and When the phase difference α (= −159.6 °) of the current I _RS is a value within a predetermined first overload / short-circuit detection phase difference range (for example, −203 ° to −90 °), “T− It is determined that an R-phase short circuit has occurred.
Further, the 3E relay 20 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow. Is the overload / short circuit detection current change rate value (eg, 1.15) or more, the voltage change rate L _TR (= 0.8) of the TR phase line voltage V _TR is the second overload / short circuit The detected voltage change rate value (for example, 0.8) or less and the phase difference (= −105 °) of the combined current I _RS is the second overload / short-circuit detection phase difference range (for example, −210 ° to If the value is not within the range of −150 °, it is determined that “TR phase short circuit has occurred”.
(E) Three-phase short circuit detection The 3E relay 20 has a current change rate K _RS (= 1.15) of the combined current I _RS that is equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15), Further, the voltage change rate L _TR (= 0.8) of the TR phase line voltage V _TR is equal to or less than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and the combined current I _{If the RS} phase difference (= −165 °) is within the second overload / short-circuit detection phase difference range (for example, −210 ° to −150 °), it is determined that “three-phase short-circuit has occurred”. To do.

次に、３Ｅリレー２０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について、図６および図７を参照して詳しく説明する。   Next, a method for detecting the RS reciprocal phase, the ST reciprocal phase, and the TR reciprocal phase in the 3E relay 20 will be described in detail with reference to FIGS. 6 and 7.

（１）正常時の合成電流Ｉ_(R-S)0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは上記（１−１）式から（１−５）式でそれぞれ表される（図６（ａ），（ｂ）参照）。 (1) Combined current I _{(RS) 0} and TR phase line voltage V _TR0 at normal time
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the above equations (1-1) to (1-5) (see FIGS. 6A and 6B).

（２）Ｒ−Ｓ相反相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相およびＳ相が逆になる（Ｒ−Ｓ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（７−１）式から（７−７）式でそれぞれ表される（図６（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （７−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （７−２）
θ_R-S＝１５０° （７−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （７−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （７−５）
θ_TR＝２７０° （７−６）
α＝θ_R-S−θ_TR＝１５０°−２７０°＝−１２０° （７−７） (2) Composite current I _RS and TR phase line voltage V _TR during _RS- phase reciprocal phase
When the R phase and S phase of the three-phase power supply line are reversed (R-S phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V The value of _TR | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the phase difference α of the combined current I _RS are expressed by equations (7-1) to (7-7), respectively (FIG. 6 ( b-1) and (b-2)).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (7-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 3 ^1/2 / 3 ^1/2 = 1 (7-2)
θ _RS = 150 ° (7-3)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (7-4)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (7-5)
θ _TR = 270 ° (7-6)
α = θ _RS −θ _TR = 150 ° -270 ° = −120 ° (7-7)

（３）Ｓ−Ｔ相反相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相およびＴ相が逆になる（Ｓ−Ｔ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（８−１）式から（８−７）式でそれぞれ表される（図７（ａ−１），（ａ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （８−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （８−２）
θ_R-S＝３０° （８−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （８−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （８−５）
θ_TR＝１５０° （８−６）
α＝θ_R-S−θ_TR＝３０°−１５０°＝−１２０° （８−７） (3) Composite current I _RS and TR phase line voltage V _TR during S-T phase opposite phase
When the S phase and T phase of the three-phase power supply line are reversed (ST phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V The value of _TR | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the phase difference α of the combined current I _RS are expressed by equations (8-1) to (8-7), respectively (FIG. 7 ( a-1) and (a-2)).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (8-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 3 ^1/2 / 3 ^1/2 = 1 (8-2)
θ _RS = 30 ° (8-3)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (8-4)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (8-5)
θ _TR = 150 ° (8-6)
α = θ _RS −θ _TR = 30 ° −150 ° = −120 ° (8-7)

（４）Ｔ−Ｒ相反相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相およびＲ相が逆になる（Ｔ−Ｒ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（９−１）式から（９−７）式でそれぞれ表される（図７（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （９−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （９−２）
θ_R-S＝２７０° （９−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （９−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （９−５）
θ_TR＝３０° （９−６）
α＝θ_R-S−θ_TR＝２７０°−３０°＝２４０°＝−１２０° （９−７） (4) Combined current I _RS and TR phase line voltage V _TR at the time of TR phase opposite phase
When the T phase and R phase of the three-phase power supply line are reversed (TR phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V _TR value | V _TR |, voltage change rate L _TR, phase θ _TR, and phase difference α of combined current I _RS are expressed by equations (9-1) to (9-7), respectively (FIG. 7 ( b-1) and (b-2)).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (9-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 3 ^1/2 / 3 ^1/2 = 1 (9-2)
θ _RS = 270 ° (9-3)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (9-4)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (9-5)
θ _TR = 30 ° (9-6)
α = θ _RS −θ _TR = 270 ° −30 ° = 240 ° = −120 ° (9-7)

（５）反相の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が所定の反相検出電流変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が所定の反相検出電圧変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、合成電流Ｉ_R-Sの位相差α（＝−１２０°）が所定の反相検出位相差範囲（たとえば、−１５０°〜−９０°）内の値であると、「反相が発生した」と判定する。 (5) Detection of opposite phase In the 3E relay 20, the current change rate K _RS (= 1) of the combined current I _RS is a value within a predetermined opposite phase detection current change rate range (for example, 0.9 to 1.1). And the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is a value within a predetermined antiphase detection voltage change rate range (for example, 0.9 to 1.1), and , the phase difference between the combined current _{I RS α (= - 120 °} ) is specified anti-phase phase difference detection range (for example, -150 ° ~-90 °) when a value within a "reverse phase occurs" judge.

次に、３Ｅリレー２０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について、図８および図９を参照して詳しく説明する。   Next, FIG. 8 and FIG. 8 show detection methods for the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase disconnections of the star-connected three-phase power supply line in the 3E relay 20. This will be described in detail with reference to FIG.

（１）正常時の合成電流Ｉ_(R-S)0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは上記（１−１）式から（１−５）式でそれぞれ表される（図８（ａ−１），（ａ−２）参照）。 (1) Combined current I _{(RS) 0} and TR phase line voltage V _TR0 at normal time
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the above equations (1-1) to (1-5) (see FIGS. 8A-1 and 8A-2). .

（２）Ｒ相欠相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相の欠相（Ｒ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（１０−１）式から（１０−７）式でそれぞれ表される（図８（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_S｜＝｜Ｉ_S0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （１０−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2／２）／３^1/2＝０．５ （１０−２）
θ_R-S＝２７０° （１０−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_T｜＝｜Ｖ_T0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （１０−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（３^1/2／２）／３^1/2＝０．５ （１０−５）
θ_TR＝２７０° （１０−６）
α＝θ_R-S−θ_TR＝２７０°−１７０°＝０° （１０−７） (2) Composite current I _RS and TR phase line voltage V _TR when R phase is open
When an R-phase phase loss (R-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, voltage change rate L _TR, phase θ _TR, and phase difference α of combined current I _RS are expressed by equations (10-1) to (10-7), respectively (FIG. 8 (b-1)) ), (B-2)).
| I _RS | = | I _R −I _S | = | I _S | = | I _S0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (10-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (10-2)
θ _RS = 270 ° (10-3)
| V _TR | = | V _T −V _R | = | V _T | = | V _T0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (10-4)
L _TR = | V _TR | / | V _TR0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (10−5)
θ _TR = 270 ° (10-6)
α = θ _RS −θ _TR = 270 ° −170 ° = 0 ° (10−7)

（３）Ｓ相欠相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相の欠相（Ｓ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（１１−１）式から（１１−７）式でそれぞれ表される（図９（ａ−１），（ａ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_R｜＝｜Ｉ_R0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （１１−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2／２）／３^1/2＝０．５ （１１−２）
θ_R-S＝３０° （１１−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_T｜＋｜Ｖ_R｜
＝（｜Ｖ_T0｜×ｃｏｓ３０°）＋（｜Ｖ_R0｜×ｃｏｓ３０°）
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （１１−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （１１−５）
θ_TR＝２１０° （１１−６）
α＝θ_R-S−θ_TR＝３０°−２１０°＝−１８０°＝１８０° （１１−７） (3) Combined current I _RS and TR phase line voltage V _TR when S phase is open
When the S-phase phase loss (S-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, the phase difference α between the voltage change rate L _TR and the phase theta _TR resultant current I _RS respectively represented by (11-7) expression (11-1) expression (Fig. 9 (a-1 ), (A-2)).
| I _RS | = | I _R −I _S | = | I _R | = | I _R0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (11-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (11-2)
θ _RS = 30 ° (11-3)
| V _TR | = | V _T −V _R | = | V _T | + | V _R |
= (| V _T0 | × cos 30 °) + (| V _R0 | × cos 30 °)
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (11-4)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (11-5)
θ _TR = 210 ° (11-6)
α = θ _RS −θ _TR = 30 ° −210 ° = −180 ° = 180 ° (11−7)

（４）Ｔ相欠相時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相の欠相（Ｔ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは（１２−１）式から（１２−７）式でそれぞれ表される（図９（ｂ−１），（ｂ−２）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_R｜＋｜Ｉ_S｜
＝｜Ｉ_R0｜×ｃｏｓ３０°＋｜Ｉ_S0｜×ｃｏｓ３０°
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （１２−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （１２−２）
θ_R-S＝３３０° （１２−３）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_R｜＝｜Ｖ_R0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （１２−４）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（３^1/2／２）／３^1/2＝０．５ （１２−５）
θ_TR＝１５０° （１２−６）
α＝θ_R-S−θ_TR＝３３０°−１５０°＝１８０° （１２−７） (4) Composite current I _RS and T-phase line voltage V _TR when T phase is open
When a T-phase phase loss (T-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, voltage change rate L _TR, phase θ _TR, and phase difference α of combined current I _RS are expressed by equations (12-1) to (12-7), respectively (FIG. 9 (b-1) ), (B-2)).
| I _RS | = | I _R −I _S | = | I _R | + | I _S |
= | I _R0 | × cos 30 ° + | I _S0 | × cos 30 °
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (12-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 3 ^1/2 / 3 ^1/2 = 1 (12-2)
θ _RS = 330 ° (12-3)
| V _TR | = | V _T −V _R | = | V _R | = | V _R0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (12-4)
L _TR = | V _TR | / | V _TR0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (12−5)
θ _TR = 150 ° (12-6)
α = θ _RS −θ _TR = 330 ° -150 ° = 180 ° (12-7)

（５）Ｒ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相の断線（Ｒ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１０−１）式から（１０−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。また、合成電流Ｉ_R-Sの位相差αは（１３−１）式で表される。
α＝θ_R-S−θ_TR＝２７０°−２１０°＝６０° （１３−１） (5) Composite current I _RS and R phase line voltage V _TR when R phase is broken
When the R-phase disconnection (R-phase disconnection) of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by 3), and the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. The Further, the phase difference α of the combined current I _RS is expressed by the equation (13-1).
α = θ _RS −θ _TR = 270 ° −210 ° = 60 ° (13-1)

（６）Ｓ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相の断線（Ｓ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１１−１）式から（１１−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。また、合成電流Ｉ_R-Sの位相差αは（１３−２）式で表される。
α＝θ_R-S−θ_TR＝２１０°−３０°＝１８０° （１３−２） (6) Synthetic current I _RS and TR phase line voltage V _TR when S phase is broken
When the S-phase disconnection (S-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (11-1) as (11− 3) each represented by the formula, the value of the voltage V _TR - TR phase line | V _TR |, the voltage change rate L _TR and the phase theta _TR is represented respectively by (2-6) below from the above (2-4) below The Further, the phase difference α of the combined current I _RS is expressed by the equation (13-2).
α = θ _RS −θ _TR = 210 ° −30 ° = 180 ° (13-2)

（７）Ｔ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相の断線（Ｔ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１２−１）式から（１２−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。また、合成電流Ｉ_R-Sの位相差αは（１３−３）式で表される。
α＝θ_R-S−θ_TR＝３３０°−２１０°＝１２０° （１３−３）
（８）Ｒ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出
（ａ）Ｒ相欠相の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が所定の欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が所定の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、合成電流Ｉ_R-Sの位相差α（＝０°）が所定の第１の欠相・断線検出位相差範囲（たとえば、−３０°〜３０°）内の値であると、「Ｒ相欠相が発生した」と判定する。
（ｂ）Ｓ相欠相またはＳ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１８０°）が所定の第２の欠相・断線検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｓ相欠相またはＳ相断線が発生した」と判定する。
（ｃ）Ｔ相欠相の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、合成電流Ｉ_R-Sの位相差α（＝１８０°）が第２の欠相・断線検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｔ相欠相が発生した」と判定する。
（ｄ）Ｒ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝６０°）が所定の第３の欠相・断線検出位相差範囲（たとえば、３０°〜９０°）内の値であると、「Ｒ相断線が発生した」と判定する。
（ｅ）Ｔ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１２０°）が所定の第４の断線検出位相差範囲（たとえば、９０°〜１５０°）内の値であると、「Ｔ相断線が発生した」と判定する。 (7) Composite current I _RS and TR phase line voltage V _TR when T phase is broken
When the T-phase disconnection (T-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (12-1) as 3), the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. The Further, the phase difference α of the combined current I _RS is expressed by the equation (13-3).
α = θ _RS −θ _TR = 330 ° −210 ° = 120 ° (13-3)
(8) R Aiketsusho, S Aiketsusho, T Aiketsusho, detection 3E relay 20 of the R-phase disconnection, S-phase disconnection and T-phase detection of disconnection (a) R-phase open-phase is the combined current I _RS The current change rate K _RS (= 0.5) is a value within a predetermined open phase / disconnection detection current change rate range (for example, 0.4 to 0.6), and the TR phase line voltage V _TR The voltage change rate L _TR (= 0.5) is a value within a predetermined open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the phase difference α of the combined current I _RS If (= 0 °) is a value within a predetermined first phase loss / disconnection detection phase difference range (for example, −30 ° to 30 °), it is determined that “R phase phase loss has occurred”.
(B) Detection of S-phase open phase or S-phase disconnection In the 3E relay 20, the current change rate K _RS (= 0.5) of the combined current I _RS is in the open phase / open-circuit detection current change rate range (for example, 0.4 ˜0.6), and the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is within the phase loss / breakage detection voltage change rate range (for example, 0.4 to 0.6). ) And the phase difference α (= 180 °) of the combined current I _RS is a value within a predetermined second phase failure / disconnection detection phase difference range (for example, 150 ° to 210 °). Then, it is determined that “the S phase missing phase or the S phase disconnection has occurred”.
(C) Detection of T-phase phase loss In the 3E relay 20, the current change rate K _RS (= 1) of the combined current I _RS is within the phase loss / disconnection detection current rate of change range (for example, 0.4 to 0.6). And the voltage change rate L _TR (= 0.5) of the TR phase line-to-line voltage V _TR is a value within the phase loss / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the phase difference α (= 180 °) of the combined current I _RS is a value within the second phase failure / disconnection detection phase difference range (for example, 150 ° to 210 °). It is determined that a phase has occurred.
(D) Detection of R-phase disconnection In the 3E relay 20, the current change rate K _RS (= 0.5) of the combined current I _{RS is in} the range of open-phase / disconnection detection current change rate (for example, 0.4 to 0.6). And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is a value within the open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the phase difference α (= 60 °) of the combined current I _RS is a value within a predetermined third open phase / disconnection detection phase difference range (for example, 30 ° to 90 °). It is determined that a disconnection has occurred.
(E) Detection of T-phase disconnection The 3E relay 20 has a current change rate K _RS (= 1) of the combined current I _RS within an open / break detection current change rate range (for example, 0.4 to 0.6). Is not a value, and the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is not a value within the phase loss / breakage detection voltage change rate range (for example, 0.4 to 0.6). Further, if the phase difference α (= 120 °) of the combined current I _RS is a value within a predetermined fourth disconnection detection phase difference range (for example, 90 ° to 150 °), “T-phase disconnection has occurred”. It is determined.

次に、３Ｅリレー２０におけるデルタ結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出方法について、図１０を参照して詳しく説明する。   Next, FIG. 10 shows a method for detecting an R phase, S phase, T phase, RS phase, ST phase, and TR phase disconnection of the delta-connected three-phase power supply line in the 3E relay 20. This will be described in detail with reference.

（１）正常時の合成電流Ｉ_(R-S)0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは上記（１−１）式から（１−５）式でそれぞれ表される。 (1) Combined current I _{(RS) 0} and TR phase line voltage V _TR0 at normal time
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the above equations (1-1) to (1-5).

（２）Ｒ相欠相、Ｓ相欠相およびＴ相欠相の検出
３Ｅリレー２０は、上述したスター結線された三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相の検出と同様にして、デルタ結線された三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相を検出する。 (2) Detection of R-phase, S-phase, and T-phase phases In the same manner as the detection, the R phase missing phase, the S phase missing phase, and the T phase missing phase of the three-phase power line connected in the delta connection are detected.

（３）ＲＳ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲＳ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは（１４−１）式から（１４−３）式でそれぞれ表される（図１０（ａ）参照）。また、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。さらに、合成電流Ｉ_R-Sの位相差αは（１４−４）式で表される。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜
＝（｜Ｉ_R｜²＋｜Ｉ_S｜²−２×｜Ｉ_R｜×｜Ｉ_S｜×ｃｏｓ６０°）^1/2
＝｛（｜Ｉ_R0｜／３^1/2）²＋（｜Ｉ_S0｜／３^1/2）²−２×（｜Ｉ_R0｜／３^1/2）×（｜Ｉ_S0｜／３^1/2）×ｃｏｓ６０°｝^1/2
＝｛（１／３^1/2）²＋（１／３^1/2）²−２×（１／３^1/2）×（１／３^1/2）×ｃｏｓ６０°｝^1/2
＝（１／３＋１／３−１／３）^1/2＝１／３^1/2 （１４−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（１／３^1/2）／３^1/2
＝１／３（＝０．３３３） （１４−２）
θ_R-S＝３３０° （１４−３）
α＝θ_R-S−θ_TR＝３３０°−２１０°＝１２０° （１４−４） (3) Combined current I _RS and _RS phase line voltage V _TR when RS phase is disconnected
When the RS phase disconnection of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by the equations (14-1) to (14-3), respectively. (See FIG. 10A). Further, the value | V _TR | of the TR phase line voltage V _TR , the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. Furthermore, the phase difference α of the combined current I _RS is expressed by the equation (14-4).
| I _RS | = | I _R −I _S |
= (| I _R | ² + | I _S | ² −2 × | I _R | × | I _S | × cos 60 °) ^1/2
= {(| I _R0 | / 3 ^1/2 ) ² + (| I _S0 | / 3 ^1/2 ) ² −2 × (| I _R0 | / 3 ^1/2 ) × (| I _S0 | / 3 ^{1 / 2} ) x cos 60 °} ^1/2
= {(1/3 ^1/2 ) ² + (1/3 ^1/2 ) ² −2 × (1/3 ^1/2 ) × (1/3 ^1/2 ) × cos 60 °} ^1/2
= (1/3 + 1 / 3-1 / 3) ^1/2 = 1/3 ^1/2 (14-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (1/3 ^1/2 ) / 3 ^1/2
= 1/3 (= 0.333) (14-2)
θ _RS = 330 ° (14-3)
α = θ _RS −θ _TR = 330 ° −210 ° = 120 ° (14-4)

（４）ＳＴ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳＴ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは（１５−１）式から（１５−３）式でそれぞれ表される（図１０（ｂ）参照）。また、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。さらに、合成電流Ｉ_R-Sの位相差αは（１５−４）式で表される。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜
＝｛｜Ｉ_R｜²＋｜Ｉ_S｜²−２×｜Ｉ_R｜×｜Ｉ_S｜×ｃｏｓ１５０°｝^1/2
＝｛｜Ｉ_R0｜²＋（｜Ｉ_S0｜／３^1/2）²−２×｜Ｉ_R0｜×（｜Ｉ_S0｜／３^1/2）×ｃｏｓ１５０°｝^1/2
＝｛１²＋（１／３^1/2）²−２×１×（１／３^1/2）×ｃｏｓ１５０°｝^1/2
＝（１＋１／３＋１）^1/2＝（７／３）^1/2 （１５−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（７／３）^1/2／３^1/2＝７^1/2／３
（＝０．８８２） （１５−２）
θ_R-S＝３４９．１° （１５−３）
α＝θ_R-S−θ_TR＝３４９．１°−２１０°＝１３９．１° （１５−４） (4) Combined current I _RS and ST phase line voltage V _TR when ST phase is disconnected
When the ST phase disconnection of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by the equations (15-1) to (15-3), respectively. (See FIG. 10B). Further, the value | V _TR | of the TR phase line voltage V _TR , the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. Furthermore, the phase difference α of the combined current I _RS is expressed by the equation (15-4).
| I _RS | = | I _R −I _S |
= {| I _R | ² + | I _S | ² −2 × | I _R | × | I _S | × cos 150 °} ^1/2
= {| I _R0 | ² + (| I _S0 | / 3 ^1/2 ) ² −2 × | I _R0 | × (| I _S0 | / 3 ^1/2 ) × cos 150 °} ^1/2
= {1 ² + (1/3 ^1/2 ) ² −2 × 1 × (1/3 ^1/2 ) × cos 150 °} ^1/2
= (1 + 1/3 + 1) ^1/2 = (7/3) ^1/2 (15-1)
_{K RS = | I RS | /} | I (RS) 0 | = (7/3) 1/2 / 3 1/2 = 7 1/2 / 3
(= 0.882) (15-2)
θ _RS = 349.1 ° (15-3)
α = θ _RS −θ _TR = 349.1 ° −210 ° = 139.1 ° (15-4)

（４）ＴＲ相断線時の合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴＲ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは（１６−１）式から（１６−３）式でそれぞれ表される（図１０（ｃ）参照）。また、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される（図３（ｂ）参照）。さらに、合成電流Ｉ_R-Sの位相差αは（１６−４）式で表される。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜
＝｛｜Ｉ_R｜²＋｜Ｉ_S｜²−２×｜Ｉ_R｜×｜Ｉ_S｜×ｃｏｓ１５０°｝^1/2
＝｛（｜Ｉ_R0｜／３^1/2）²＋｜Ｉ_S0｜²−２×（｜Ｉ_R0｜／３^1/2）×｜Ｉ_S0｜×ｃｏｓ１５０°｝^1/2
＝｛（１／３^1/2）²＋１²−２×（１／３^1/2）×１×ｃｏｓ１５０°｝^1/2
＝（１／３＋１＋１）^1/2＝（７／３）^1/2 （１６−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（７／３）^1/2／３^1/2＝７^1/2／３
（＝０．８８２） （１６−２）
θ_R-S＝３１０．９° （１６−３）
α＝θ_R-S−θ_TR＝３１０．９°−２１０°＝１００．９° （１６−４） (4) Composite current I _RS and TR phase line voltage V _TR when TR phase is disconnected
When the TR phase disconnection of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by the equations (16-1) to (16-3), respectively. (See FIG. 10C). Further, the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively (FIG. 3B). )reference). Furthermore, the phase difference α of the combined current I _RS is expressed by the equation (16-4).
| I _RS | = | I _R −I _S |
= {| I _R | ² + | I _S | ² −2 × | I _R | × | I _S | × cos 150 °} ^1/2
= {(| I _R0 | / 3 ^1/2 ) ² + | I _S0 | ² −2 × (| I _R0 | / 3 ^1/2 ) × | I _S0 | × cos 150 °} ^1/2
= {(1/3 ^1/2 ) ² +1 ² -2 × (1/3 ^1/2 ) × 1 × cos 150 °} ^1/2
= (1/3 + 1 + 1) ^1/2 = (7/3) ^1/2 (16-1)
_{K RS = | I RS | /} | I (RS) 0 | = (7/3) 1/2 / 3 1/2 = 7 1/2 / 3
(= 0.882) (16-2)
θ _RS = 310.9 ° (16-3)
α = θ _RS −θ _TR = 310.9 ° −210 ° = 100.9 ° (16-4)

（５）ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出
（ａ）ＲＳ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．３３３）が所定の第１の断線検出電流変化率範囲（たとえば、０．２〜０．４）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でないと、「ＲＳ相断線が発生した」と判定する。
（ｂ）ＳＴ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が所定の第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１３９．１°）が所定の第１の断線検出位相差範囲（たとえば、１３０°〜１５０°）内の値であると、「ＳＴ相断線が発生した」と判定する。
（ｃ）ＴＲ相断線の検出
３Ｅリレー２０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１００．９°）が所定の第２の断線検出位相差範囲（たとえば、９０°〜１１０°）内の値であると、「ＴＲ相断線が発生した」と判定する。 (5) Detection of RS phase disconnection, ST phase disconnection, and TR phase disconnection (a) Detection of RS phase disconnection The 3E relay 20 has a predetermined current change rate K _RS (= 0.333) of the combined current I _RS . Is a value within the disconnection detection current change rate range (for example, 0.2 to 0.4), and the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is the phase loss / disconnection detection voltage. If it is not a value within the change rate range (for example, 0.4 to 0.6), it is determined that “RS phase disconnection has occurred”.
(B) Detection of ST phase disconnection In the 3E relay 20, the current change rate K _RS (= 0.882) of the combined current I _RS is a predetermined second disconnection detection current change rate range (for example, 0.8 to 0. 9), and the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is within the phase loss / breakage detection voltage change rate range (for example, 0.4 to 0.6). If the phase difference α (= 139.1 °) of the combined current I _RS is not a value and is a value within a predetermined first disconnection detection phase difference range (for example, 130 ° to 150 °), “ST It is determined that a phase break has occurred.
(C) TR phase disconnection detection In the 3E relay 20, the current change rate K _RS (= 0.882) of the combined current I _RS is in the second disconnection detection current change rate range (for example, 0.8 to 0.9). And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is a value within the open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the phase difference α (= 100.9 °) of the combined current I _RS is a value within a predetermined second disconnection detection phase difference range (for example, 90 ° to 110 °), “TR phase disconnection Is determined to occur.

次に、３Ｅリレー２０の構成について、図１１を参照して説明する。
３Ｅリレー２０は、図１１に示すように、入力変換器２１と、アナログ入力部２２と、メモリ２３と、電流変化率算出部２４と、電圧変化率算出部２５と、位相変化角算出部２６と、位相差算出部２７と、リレー演算処理部２８と、整定・表示部２９と、入出部３０と、外部機器Ｉ／Ｆ部３１とを備える。 Next, the configuration of the 3E relay 20 will be described with reference to FIG.
As illustrated in FIG. 11, the 3E relay 20 includes an input converter 21, an analog input unit 22, a memory 23, a current change rate calculation unit 24, a voltage change rate calculation unit 25, and a phase change angle calculation unit 26. A phase difference calculation unit 27, a relay calculation processing unit 28, a settling / display unit 29, an input / output unit 30, and an external device I / F unit 31.

ここで、入力変換器２１は、クロス貫通変流器１１から入力される合成電流Ｉ_R-Sおよび計器用変成器１２から入力されるＴＲ相線間電圧Ｖ_TRのレベルをアナログ入力部２２の処理に適したレベルに変換する。
アナログ入力部２２は、バンドパスフィルタとサンプリングホールド回路とマルチプレクサ回路とアナログ／ディジタル変換器とを備え、入力変換器２１から入力されるアナログの合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TRをディジタルの合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TRに変換する。
メモリ２３は、アナログ入力部２２によってディジタルデータに変換された合成電流Ｉ_R-SおよびＴＲ相線間電圧Ｖ_TRを格納するためのものである。 Here, the input converter 21 processes the level of the combined current I _RS input from the cross-through current transformer 11 and the TR phase line voltage V _TR input from the instrument transformer 12 to the analog input unit 22. Convert to a suitable level.
The analog input unit 22 includes a band-pass filter, a sampling hold circuit, a multiplexer circuit, and an analog / digital converter, and digitally outputs the analog combined current I _RS and the TR phase line voltage V _TR input from the input converter 21. The combined current I _RS and the TR phase line voltage V _TR are converted.
The memory 23 is for storing the combined current I _RS and the TR phase line voltage V _TR converted into digital data by the analog input unit 22.

電流変化率算出部２４は、メモリ２３に格納されているＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値に基づいて、アナログ入力部２２から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sを算出する。 The current change rate calculation unit 24 is a composite current input from the analog input unit 22 based on the rated current values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T stored in the memory 23. calculating a current change rate K _RS of I _RS.

電圧変化率算出部２５は、メモリ２３に格納されているＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値に基づいて、アナログ入力部２２から入力されるＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRを算出する。 The voltage change rate calculation unit 25 is a TR phase input from the analog input unit 22 based on the rated voltage values of the R-phase, S-phase, and T-phase voltages V _R , V _S , and V _T stored in the memory 23. calculating the voltage change rate L _TR line voltage V _TR.

位相変化角算出部２６と、アナログ入力部２２から入力されるＴＲ相線間電圧Ｖ_TRの位相θ_TRからメモリ２３に格納されている正常時のＴＲ相線間電圧Ｖ_TRの位相θ_TR0を引くことにより、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRを算出する。 From the phase θ _{TR of the} TR phase line voltage V _TR input from the phase change angle calculation unit 26 and the analog input unit 22, the phase θ _TR0 of the normal TR phase line voltage V _TR stored in the memory 23 is calculated. it allows to calculate the phase shift angle [Delta] [theta] _TR of the voltage V _TR - TR phase line pulling.

位相差算出部２７は、アナログ入力部２２から入力される合成電流Ｉ_R-Sの位相θ_R-Sからアナログ入力部２２から入力されるＴＲ相線間電圧Ｖ_TRの位相θ_TRを引くことにより、合成電流Ｉ_R-Sの位相差αを算出する。 The phase difference calculation unit 27 subtracts the phase θ _TR of the TR phase line voltage V _TR input from the analog input unit 22 from the phase θ _RS of the combined current I _RS input from the analog input unit 22, thereby generating a combined current. The phase difference α of I _RS is calculated.

リレー演算処理部２８は、電流変化率算出部２４によって算出された合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sと電圧変化率算出部２５によって算出されたＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRと位相変化角算出部２６によって算出されたＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRと位相差算出部２７によって算出された合成電流Ｉ_R-Sの位相差αと基づいて、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡、三相短絡、Ｒ−Ｓ相反相、Ｓ−Ｔ相反相、Ｔ−Ｒ相反相、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線、Ｔ相断線、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出すると、第１乃至第３の遮断器３₁〜３₃（図１参照）をそれぞれ遮断するための第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を生成し、生成した第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を入出力部３０および外部機器インターフェース部３１を介して第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The relay calculation processing unit 28 includes a current change rate K _RS of the combined current I _RS calculated by the current change rate calculation unit 24 and a voltage change rate L of the TR phase line voltage V _TR calculated by the voltage change rate calculation unit 25. _{Based on} the phase change angle Δθ _{TR of} the TR phase line voltage V _TR calculated by _TR and the phase change angle calculation unit 26 and the phase difference α of the combined current I _RS calculated by the phase difference calculation unit 27, overload, R-S phase short circuit, S-T phase short circuit, T-R phase short circuit, three-phase short circuit, R-S reciprocal phase, S-T reciprocal phase, TR reciprocal phase, R in star-connected three-phase power supply line Phase open phase, S phase open phase, T phase open phase, R phase open wire, S phase open wire, T phase open wire, R phase open phase, S phase open phase, T phase open phase in delta-connected three-phase power supply line, RS phase disconnection, when detecting the ST-phase disconnection and TR phase disconnection, the first to third circuit breakers 3 ₁ to 3 ₃ (see FIG. 1) its The first to third trip signal T ₁ generates through T _3, the first through third trip signal T ₁ through T ₃ input-output unit 30 and an external device interface unit 31 which is generated for interrupting, respectively To the _first to _third circuit breakers 3 _{1 to} 3 ₃ , respectively.

整定・表示部２９は、過負荷・短絡検出電流変化率値、第１および第２の過負荷・短絡検出電圧変化率値、第１および第２の過負荷・短絡検出位相変化角範囲、第１および第２の過負荷・短絡検出位相差範囲、反相検出電流変化率範囲、反相検出電圧変化率範囲、反相検出位相差範囲、欠相・断線検出電流変化率範囲、第１および第２の断線検出電流変化率範囲、欠相・断線検出電圧変化率範囲、第１乃至第４の欠相・断線検出位相差範囲並びに第１および第２の断線検出位相差範囲に基づいてリレー整定処理を行うとともに、整定値などを外部に表示する。   The settling / display unit 29 includes an overload / short-circuit detection current change rate value, first and second overload / short-circuit detection voltage change rate values, first and second overload / short-circuit detection phase change angle ranges, 1 and 2 overload / short circuit detection phase difference range, anti-phase detection current change rate range, anti-phase detection voltage change rate range, anti-phase detection phase difference range, open phase / disconnection detection current change rate range, Relay based on the second disconnection detection current change rate range, the phase loss / disconnection detection voltage change rate range, the first to fourth phase loss / disconnection detection phase difference ranges, and the first and second disconnection detection phase difference ranges A settling process is performed and a settling value is displayed outside.

次に、以下に示す条件下におけるリレー演算処理部２８の動作について説明する。
（１）過負荷・短絡検出電流変化率値＝１．１５、第１の過負荷・短絡検出電圧変化率値＝０．９６、第２の過負荷・短絡検出電圧変化率値＝０．８、第１の過負荷・短絡検出位相変化角範囲＝５．２°〜３０°、第２の過負荷・短絡検出位相変化角範囲＝−５．２°〜−３０°、第１の過負荷・短絡検出位相差範囲＝−２０３°〜−９０°、第２の過負荷・短絡検出位相差範囲＝−２１０°〜−１５０°
（２）反相検出電流変化率範囲＝０．９〜１．１、反相検出電圧変化率範囲＝０．９〜１．１、反相検出位相差範囲＝−１５０°〜−９０°
（３）欠相・断線検出電流変化率範囲＝０．４〜０．６、第１の断線検出電流変化率範囲＝０．２〜０．４、第２の断線検出電流変化率範囲＝０．８〜０．９、欠相・断線検出電圧変化率範囲＝０．４〜０．６、第１の欠相・断線検出位相差範囲＝−３０°〜３０°、第２の欠相・断線検出位相差範囲＝１５０°〜２１０°、第３の欠相・断線検出位相差範囲＝３０°〜９０°、第４の欠相・断線検出位相差範囲＝９０°〜１５０°、第１の断線検出位相差範囲＝１３０°〜１５０°、第２の断線検出位相差範囲＝９０°〜１１０° Next, the operation of the relay calculation processing unit 28 under the following conditions will be described.
(1) Overload / short-circuit detection current change rate value = 1.15, first overload / short-circuit detection voltage change rate value = 0.96, second overload / short-circuit detection voltage change rate value = 0.8 First overload / short-circuit detection phase change angle range = 5.2 ° to 30 °, second overload / short-circuit detection phase change angle range = −5.2 ° to −30 °, first overload Short-circuit detection phase difference range = −203 ° to −90 °, second overload / short-circuit detection phase difference range = −210 ° to −150 °
(2) Anti-phase detection current change rate range = 0.9 to 1.1, anti-phase detection voltage change rate range = 0.9 to 1.1, anti-phase detection phase difference range = −150 ° to −90 °
(3) Phase loss / disconnection detection current change rate range = 0.4 to 0.6, first disconnection detection current change rate range = 0.2 to 0.4, second disconnection detection current change rate range = 0 .8 to 0.9, phase loss / breakage detection voltage change rate range = 0.4 to 0.6, first phase failure / breakage detection phase difference range = −30 ° to 30 °, second phase loss / Disconnection detection phase difference range = 150 ° to 210 °, third open phase / disconnection detection phase difference range = 30 ° to 90 °, fourth open phase / disconnection detection phase difference range = 90 ° to 150 °, first Disconnection detection phase difference range = 130 ° to 150 °, second disconnection detection phase difference range = 90 ° to 110 °

まず、過負荷または短絡事故発生時のリレー演算処理部２８の動作について、図１２に示すフローチャートを参照して説明する。
リレー演算処理部２８は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）以上であるか否かを調べ（ステップＳ１０）、電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値以上であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値（＝０．９６）以下であるか否かを調べる（ステップＳ１１）。
リレー演算処理部２８は、電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値以下でないと、「過負荷が発生した」と判定する（ステップＳ１９ａ）。 First, the operation of the relay calculation processing unit 28 when an overload or short circuit accident occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 28, the resultant current the current rate of change K _RS overload or short circuit detecting current change rate values I _RS (= 1.15) examines if the either more (step S10), and the current change rate K _{If RS} is equal to or greater than the overload / short-circuit detection current change rate value, the voltage change rate L _TR of the TR phase line voltage V _TR is equal to or less than the first overload / short-circuit detection voltage change rate value (= 0.96). It is checked whether or not there is (step S11).
If the voltage change rate L _TR is not less than or equal to the first overload / short-circuit detection voltage change rate value, the relay calculation processing unit 28 determines that “overload has occurred” (step S19a).

ステップＳ１１において電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値以下であると、リレー演算処理部２８は、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べる（ステップＳ１２）。
リレー演算処理部２８は、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下でないと、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲（＝５．２°〜３０°）内の値であるか否かを調べ（ステップＳ１３）、位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲内の値であると、「Ｒ−Ｓ相短絡が発生した」と判定し（ステップＳ１９ｂ）、一方、位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲内の値でないと、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲（＝−５．２°〜−３０°）内の値であるか否かを調べ（ステップＳ１６）、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する（ステップＳ１９ｃ）。 When the voltage change rate L _TR is equal to or less than the first overload / short circuit detection voltage change rate value in step S11, the relay calculation processing unit 28 determines that the voltage change rate L _TR is the second overload / short circuit detection voltage change rate. It is checked whether or not the value (= 0.8) or less (step S12).
Relay processing section 28, when the voltage change rate L _TR not less than the second overload or short circuit detecting voltage change rate value, the phase change angle [Delta] [theta] _TR of the voltage V _TR - TR phase line first overload or short circuit It is checked whether or not the value is within the detection phase change angle range (= 5.2 ° to 30 °) (step S13), and the phase change angle Δθ _TR is within the first overload / short-circuit detection phase change angle range. If it is a value, it is determined that “R-S phase short-circuit has occurred” (step S19b). On the other hand, if the phase change angle Δθ _TR is not within the first overload / short-circuit detection phase change angle range, change angle [Delta] [theta] _TR is checked whether the second value of the overload or short circuit detecting the phase change angle range (= -5.2 ° ~-30 ° ) in (step S16), and the phase change angle [Delta] [theta] _TR If the value is within the second overload / short-circuit detection phase change angle range, it is determined that "ST phase short-circuit has occurred" (step S19). c).

ステップＳ１２において電圧変化率Ｌ_TRが第２の短絡検出電圧変化率値以下であると、リレー演算処理部２８は、合成電流Ｉ_R-Sの位相差αが第２の過負荷・短絡検出位相差範囲（＝−２１０°〜−１５０°）内の値であるか否かを調べ（ステップＳ１８）、位相差αが第２の過負荷・短絡検出位相差範囲内の値であると、「三相短絡が発生した」と判定し（ステップＳ１９ｅ）、一方、位相差αが第２の過負荷・短絡検出位相差範囲内の値でないと、「Ｔ−Ｒ相短絡が発生した」と判定し（ステップＳ１９ｄ）。 When the voltage change rate L _TR is equal to or smaller than the second short circuit detection voltage change rate value in step S12, the relay calculation processing unit 28 determines that the phase difference α of the combined current I _RS is the second overload / short circuit detection phase difference range. (= −210 ° to −150 °) is checked (step S18). If the phase difference α is a value within the second overload / short-circuit detection phase difference range, “three-phase On the other hand, if the phase difference α is not a value within the second overload / short circuit detection phase difference range, it is determined that a “T-R phase short circuit has occurred” (step S19e) Step S19d).

ステップＳ１０において電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）未満であると、リレー演算処理部２８は、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べ（ステップＳ１４）、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下でないと、電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値（＝０．９６）以下であるか否かを調べ（ステップＳ１５）、電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値以下であると、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲（＝−５．２°〜−３０°）内の値であるか否かを調べる（ステップＳ１６）。
リレー演算処理部２８は、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する（ステップＳ１９ｃ）。 If the current change rate _KRS is less than the overload / short circuit detection current change rate value (= 1.15) in step S10, the relay calculation processing unit 28 determines that the voltage change rate _LTR is the second overload / short circuit detection. It is checked whether or not the voltage change rate value (= 0.8) or less (step S14). If the voltage change rate L _TR is not less than or equal to the second overload / short-circuit detection voltage change rate value, the voltage change rate L _TR Is less than or equal to the first overload / short circuit detection voltage change rate value (= 0.96) (step S15), and the voltage change rate L _TR is the first overload / short circuit detection voltage change rate value. If it is below, it is checked whether or not the phase change angle Δθ _TR is a value within the second overload / short-circuit detection phase change angle range (= −5.2 ° to −30 °) (step S16).
When the phase change angle Δθ _TR is a value within the second overload / short-circuit detection phase change angle range, the relay arithmetic processing unit 28 determines that “ST phase short-circuit has occurred” (step S19c).

ステップＳ１４において電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であると、リレー演算処理部２８は、位相差αが第１の過負荷・短絡検出位相差範囲（＝−２０３°〜−９０°）内の値であるか否かを調べる（ステップＳ１７）。
リレー演算処理部２８は、位相差αが第１の過負荷・短絡検出位相差範囲内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する（ステップＳ１９ｄ）。 When the voltage change rate L _TR is equal to or less than the second overload / short circuit detection voltage change rate value (= 0.8) in step S14, the relay calculation processing unit 28 determines that the phase difference α is the first overload / short circuit. It is checked whether or not the value is within a detection phase difference range (= −203 ° to −90 °) (step S17).
When the phase difference α is a value within the first overload / short circuit detection phase difference range, the relay calculation processing unit 28 determines that “TR phase short circuit has occurred” (step S19d).

リレー演算処理部２８は、以上のようにして過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡または三相短絡の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ２０）。 When the relay calculation processing unit 28 detects the occurrence of an overload, an R-S phase short circuit, an ST phase short circuit, a TR phase short circuit, or a three-phase short circuit as described above, the first to third trip signals are detected. T _{1 to} T ₃ are output (step S20).

次に、反相発生時のリレー演算処理部２８の動作について、図１３に示すフローチャートを参照して説明する。
リレー演算処理部２８は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが反相検出電流変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ２１）、電流変化率Ｋ_R-Sが反相検出電流変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが反相検出電圧変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ２２）、電圧変化率Ｌ_TRが反相検出電圧変化率範囲内の値であると、合成電流Ｉ_R-Sの位相差αが反相検出位相差範囲（＝−１５０°〜−９０°）内の値であるか否かを調べる（ステップＳ２３）。
リレー演算処理部２８は、位相差αが反相検出位相差範囲内の値であると、「反相が発生した」と判定して（ステップＳ２４）、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ２５）。 Next, the operation of the relay calculation processing unit 28 when a reverse phase occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 28 checks whether the combined current I current change rate K _RS of _RS is a value within the anti-phase detected current change rate range (= 0.9 to 1.1) (step S21), and If the current change rate K _RS is a value within the antiphase detection current change rate range, the voltage change rate L _{TR of} the TR phase line voltage V _{TR is} the antiphase detection voltage change rate range (= 0.9 to 1.1). ) (Step S22), and if the voltage change rate L _TR is a value within the anti-phase detection voltage change rate range, the phase difference α of the combined current I _RS is the anti-phase detection phase difference. It is checked whether the value is within a range (= −150 ° to −90 °) (step S23).
When the phase difference α is a value within the anti-phase detection phase difference range, the relay calculation processing unit 28 determines that “an anti-phase has occurred” (step S24), and the first to third trip signals T _1. and it outputs the through T ₃ (step S25).

次に、スター結線された三相電源線における欠相または断線発生時のリレー演算処理部２８の動作について、図１４に示すフローチャートを参照して説明する。
リレー演算処理部２８は、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ３１）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値であると、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ３２）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-Sの位相差αが第１の欠相・断線検出位相差範囲（＝−３０°〜３０°）内の値であるか否かを調べる（ステップＳ３３）。
リレー演算処理部２８は、位相差αが第１の欠相・断線検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ３９ａ）。 Next, the operation of the relay arithmetic processing unit 28 when a phase loss or disconnection occurs in a star-connected three-phase power supply line will be described with reference to the flowchart shown in FIG.
The relay arithmetic processing unit 28 checks whether or not the voltage change rate L _TR of the TR phase line voltage V _TR is a value within the phase loss / disconnection detection voltage change rate range (= 0.4 to 0.6). (Step S31) If the voltage change rate L _TR is a value within the range of the phase failure / disconnection detection voltage change rate, the current change rate K _RS of the combined current I _RS is the range of the phase failure / disconnection detection current change rate (= 0). examines whether the value of .4～0.6) in (step S32), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, the resultant current I-position of the _RS It is checked whether or not the phase difference α is a value within the first phase loss / disconnection detection phase difference range (= −30 ° to 30 °) (step S33).
When the phase difference α is a value within the first phase loss / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “R phase phase loss has occurred” (step S39a).

ステップＳ３１において電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部２８は、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ３４）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、位相差αが第２の欠相・断線検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ３５）。
リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲内の値であると、「Ｓ相欠相またはＳ相断線が発生した」と判定する（ステップＳ３９ｄ）。 If the voltage change rate _LTR is not a value within the phase loss / disconnection detection voltage change rate range in step S31, the relay processing unit 28 determines that the current change rate _KRS is the phase loss / disconnection detection current change rate range (= 0. examines whether the value of 4 to 0.6) in (step S34), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, the phase difference α is the second It is checked whether or not the value is within the open phase / disconnection detection phase difference range (= 150 ° to 210 °) (step S35).
When the phase difference α is a value within the second phase loss / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “S phase phase loss or S phase disconnection has occurred” (step S39d).

ステップＳ３２において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ３６）。
リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ３９ｃ）。 If the current change rate _KRS is not a value within the open phase / disconnection detection current change rate range in step S32, the relay calculation processing unit 28 determines that the phase difference α is equal to the second open phase / disconnection detection phase difference range (= 150 °). It is checked whether the value is within the range of ~ 210 ° (step S36).
When the phase difference α is a value within the second phase loss / disconnection detection phase difference range, the relay arithmetic processing unit 28 determines that “a T phase phase loss has occurred” (step S39c).

ステップＳ３５において位相差αが第２の欠相・断線検出位相差範囲内の値でないと、リレー演算処理部２８は、位相差αが第３の欠相・断線検出位相差範囲（＝３０°〜９０°）内の値であるか否かを調べる（ステップＳ３７）。
リレー演算処理部２８は、位相差αが第３の欠相・断線検出位相差範囲内の値であると、「Ｒ相断線が発生した」と判定する（ステップＳ３９ｄ）。 If the phase difference α is not a value within the second open phase / disconnection detection phase difference range in step S35, the relay processing unit 28 determines that the phase difference α is within the third open phase / disconnection detection phase difference range (= 30 °). It is checked whether the value is within the range of (˜90 °) (step S37).
When the phase difference α is a value within the third open phase / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “R phase disconnection has occurred” (step S39d).

ステップＳ３４において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部２８は、位相差αが第４の欠相・断線検出位相差範囲（＝９０°〜１５０°）内の値であるか否かを調べる（ステップＳ３８）。
リレー演算処理部２８は、位相差αが第４の欠相・断線検出位相差範囲内の値であると、「Ｔ相断線が発生した」と判定する（ステップＳ３９ｅ）。 If the current change rate _KRS is not a value within the phase loss / disconnection detection current change rate range in step S34, the relay calculation processing unit 28 determines that the phase difference α is the fourth phase loss / disconnection detection phase difference range (= 90 °). It is checked whether the value is within the range of (˜150 °) (step S38).
When the phase difference α is a value within the fourth open phase / disconnection detection phase difference range, the relay arithmetic processing unit 28 determines that “a T-phase disconnection has occurred” (step S39e).

リレー演算処理部２８は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線またはＴ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ４０）。 When the relay arithmetic processing unit 28 detects the occurrence of the R-phase, S-phase, T-phase, R-phase, S-phase, or T-phase disconnection as described above, the first to third and it outputs the trip signal T ₁ through T ₃ (step S40).

次に、デルタ結線された三相電源線における欠相または断線発生時のリレー演算処理部２８の動作について、図１５および図１６に示すフローチャートを参照して説明する。
リレー演算処理部２８は、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ４１）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値であると、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ４２）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-Sの位相差αが第１の欠相・断線検出位相差範囲（＝−３０°〜３０°）内の値であるか否かを調べる（ステップＳ４３）。
リレー演算処理部２８は、位相差αが第１の欠相・断線検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ５１ａ）。 Next, the operation of the relay arithmetic processing unit 28 when a phase loss or disconnection occurs in the delta-connected three-phase power supply line will be described with reference to the flowcharts shown in FIGS. 15 and 16.
The relay arithmetic processing unit 28 checks whether or not the voltage change rate L _TR of the TR phase line-to-line voltage V _TR is a value within the phase loss / disconnection detection voltage change rate range (= 0.4 to 0.6). (Step S41) When the voltage change rate L _TR is a value within the range of the phase failure / disconnection detection voltage change rate, the current change rate K _RS of the combined current I _RS is the range of the phase failure / disconnection detection current change rate (= 0). .4 to 0.6) (step S42), and if the current change rate K _RS is a value within the range of the phase failure / disconnection detection current change rate, the position of the combined current I _RS It is checked whether or not the phase difference α is a value within the first phase loss / disconnection detection phase difference range (= −30 ° to 30 °) (step S43).
If the phase difference α is a value within the first open phase / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “the R phase open phase has occurred” (step S51a).

ステップＳ４１において電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部２８は、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ４４）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、位相差αが第２の欠相・断線検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ４５）。
リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲内の値であると、「Ｓ相欠相が発生した」と判定する（ステップＳ５１ｂ）。 If the voltage change rate _LTR is not a value within the phase failure / disconnection detection voltage change rate range in step S41, the relay processing unit 28 determines that the current change rate _KRS is the phase loss / disconnection detection current change rate range (= 0.0. examines whether the value of 4 to 0.6) in (step S44), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, the phase difference α is the second It is checked whether or not the value is within the phase loss / disconnection detection phase difference range (= 150 ° to 210 °) (step S45).
When the phase difference α is a value within the second phase loss / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “S phase phase loss has occurred” (step S51b).

ステップＳ４２において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ４６）。
リレー演算処理部２８は、位相差αが第２の欠相・断線検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ５１ｃ）。 If the current change rate _KRS is not a value within the open phase / disconnection detection current change rate range in step S42, the relay calculation processing unit 28 determines that the phase difference α is equal to the second open phase / disconnection detection phase difference range (= 150 °). It is checked whether the value is within the range of ~ 210 ° (step S46).
When the phase difference α is a value within the second phase loss / disconnection detection phase difference range, the relay calculation processing unit 28 determines that “T phase phase loss has occurred” (step S51c).

ステップＳ４４において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部２８は、電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲（＝０．２〜０．４）内の値であるか否かを調べる（図１６のステップＳ４７）。
リレー演算処理部２８は、電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲内の値であると、「Ｒ相断線が発生した」と判定する（ステップＳ５１ｄ）。 If the current change rate K _RS is not a value within the phase failure / disconnection detection current change rate range in step S44, the relay processing unit 28 determines that the current change rate K _RS is within the first disconnection detection current change rate range (= 0.0. 2 to 0.4) is checked (step S47 in FIG. 16).
When the current change rate K _RS is a value within the first disconnection detection current change rate range, the relay arithmetic processing unit 28 determines that “R-phase disconnection has occurred” (step S51d).

一方、ステップＳ４７において電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲内の値でないと、リレー演算処理部２８は、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲（＝０．８〜０．９）内の値であるか否かを調べ（ステップＳ４８）、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲内の値であると、位相差αが第１の断線検出位相差範囲（＝１３０°〜１５０°）内の値であるか否かを調べる（ステップＳ４９）。
リレー演算処理部２８は、位相差αが第１の断線検出位相差範囲内の値であると、ＳＴ相断線が発生した」と判定する（ステップＳ５１ｅ）。 On the other hand, if the current change rate K _RS is not a value within the first disconnection detection current change rate range in step S47, the relay calculation processing unit 28 determines that the current change rate K _RS is equal to the second disconnection detection current change rate range (= It examines whether the value of 0.8-0.9) in (step S48), if the current rate of change K _RS is the value of the second disconnection detecting the current change rate range, the phase difference α is a It is checked whether the value is within a disconnection detection phase difference range of 1 (= 130 ° to 150 °) (step S49).
When the phase difference α is a value within the first disconnection detection phase difference range, the relay calculation processing unit 28 determines that the ST phase disconnection has occurred ”(step S51e).

一方、ステップＳ４９において位相差αが第１の断線検出位相差範囲内の値でないと、リレー演算処理部２８は、位相差αが第２の断線検出位相差範囲（＝９０°〜１１０°）内の値であるか否かを調べる（ステップＳ５０）。
リレー演算処理部２８は、位相差αが第２の断線検出位相差範囲内の値であると、「ＴＲ相断線が発生した」と判定する（ステップＳ５１ｆ）。 On the other hand, if the phase difference α is not a value within the first disconnection detection phase difference range in step S49, the relay calculation processing unit 28 determines that the phase difference α is the second disconnection detection phase difference range (= 90 ° to 110 °). It is checked whether the value is within the range (step S50).
When the phase difference α is a value within the second disconnection detection phase difference range, the relay calculation processing unit 28 determines that “TR phase disconnection has occurred” (step S51f).

リレー演算処理部２８は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線またはＴＲ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ５２）。 When the relay calculation processing unit 28 detects the occurrence of the R-phase open phase, the S-phase open phase, the T-phase open phase, the RS phase open wire, the ST phase open wire, or the TR phase open wire as described above, and it outputs the trip signal T ₁ through T ₃ (step S52).

次に、本発明の第２の実施例による保護継電システムについて、図１７乃至図２７を参照して説明する。
本実施例による保護継電システムは、図１７に示すように、三相電源線のＲ相およびＳ相がクロスするように貫通されたクロス貫通変流器４１と、三相電源線のＲ相とＴ相との間に設けられた計器用変成器４２と、クロス貫通変流器４１から入力される合成電流Ｉ_R-Sと計器用変成器４２から入力されるＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tとに基づいて三相電源線における過負荷、短絡、反相、欠相および断線を検出する三相誘導電動機用３Ｅリレー５０（以下、「３Ｅリレー５０」と称する。）とを具備する。 Next, a protection relay system according to a second embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 17, the protection relay system according to the present embodiment includes a cross-through current transformer 41 that is penetrated so that the R phase and the S phase of the three-phase power supply line cross, and the R phase of the three-phase power supply line. Instrument transformer 42 provided between the T phase and the T phase, the combined current I _RS input from the cross-through current transformer 41 and the TR phase line voltage V _TR and T input from the instrument transformer 42. A 3E relay 50 for a three-phase induction motor (hereinafter referred to as “3E relay 50”) that detects overload, short circuit, reverse phase, phase loss, and disconnection in a three-phase power source line based on the phase voltage V _T. It has.

ここで、クロス貫通変流器４１は、図１に示したクロス貫通変流器１１と同じものである。
計器用変成器４２は、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tを３Ｅリレー５０に出力する。 Here, the cross through current transformer 41 is the same as the cross through current transformer 11 shown in FIG.
The instrument transformer 42 outputs the TR phase line voltage V _TR and the T phase voltage V _T to the 3E relay 50.

３Ｅリレー５０は、クロス貫通変流器４１から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sと計器用変成器４２から入力されるＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRおよび位相変化角Δθ_TRと計器用変成器４２から入力されるＴ相電圧Ｖ_Tの電圧変化率Ｌ_Tおよび位相変化角Δθ_Tとに基づいて、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡を検出する。
また、３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-SとＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRとＴ相電圧Ｖ_Tの電圧変化率Ｌ_Tおよび位相差β（ＴＲ相線間電圧Ｖ_TRの位相θ_TRに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）とに基づいて、Ｒ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相を検出する。
さらに、３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sおよび位相差α（ＴＲ相線間電圧Ｖ_TRの位相θ_TRに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。）とＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRとＴ相電圧Ｖ_Tの電圧変化率Ｌ_Tとに基づいて、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線を検出するとともに、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出する。
３Ｅリレー５０は、以上のようにして過負荷などを検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The 3E relay 50 includes a current change rate K _RS of the combined current I _RS input from the cross-through current transformer 41, a voltage change rate L _TR and a phase of the TR phase line voltage V _TR input from the instrument transformer 42. based on the voltage change rate L _T and the phase change angle [Delta] [theta] _T T-phase voltage V _T which is input from the change angle [Delta] [theta] _TR and instrument transformer 42, overload, R-S-phase short circuit, S-T phase short-circuit , TR phase short circuit and three phase short circuit are detected.
Further, 3E relay 50 is the combined current-voltage change rate L _T and the phase difference of the voltage change rate L _TR and T-phase voltage V _T of the current change rate K _RS and TR phase line voltage V _TR of the I _RS beta (TR phase Based on the phase difference of the line voltage V _TR relative to the phase θ _TR , the lag phase is a positive value, the lead phase is a negative value, and so on. And TR reciprocal phase is detected.
Furthermore, 3E relay 50 is the phase difference for the phase theta _TR synthetic current I _RS of the current rate of change K _RS and the phase difference alpha (TR-phase line voltage V _TR, negative phase lead lag phase at a positive value indicated by the value.) and on the basis of the voltage change rate L _T of the voltage change rate L _TR and T-phase voltage V _T of the TR-phase line voltage V _TR, R Aiketsusho in three-phase power supply lines which are star-connected , S phase open phase, T phase open phase, R phase open phase, S phase open phase and T phase open phase are detected, and R phase open phase, S phase open phase, T phase open phase in delta-connected three-phase power supply line RS phase disconnection, ST phase disconnection and TR phase disconnection are detected.
When the 3E relay 50 detects an overload or the like as described above, the 3E relay 50 outputs the first to third trip signals T _{1 to} T ₃ to the first to third circuit breakers 3 _{1 to} 3 ₃ , respectively.

次に、３Ｅリレー５０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について、図１８を参照して詳しく説明する。
なお、以下の説明では、Ｒ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値を“１”とし、Ｒ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値を“１”とし、正常時のＲ相電流Ｉ_R0の位相θ_R0を０°として説明する。 Next, a method for detecting overload, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit in the 3E relay 50 will be described in detail with reference to FIG.
In the following description, the rated current values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T are “1”, and the R-phase, S-phase, and T-phase voltages V _R , V _S , V Description will be made assuming that the rated voltage value of _T is “1” and the phase θ _R0 of the R-phase current I _R0 at normal time is 0 °.

（１）正常時の合成電流Ｉ_(R-S)0、ＴＲ相線間電圧Ｖ_TR0およびＴ相電圧Ｖ_T0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは上記（１−１）式から（１−５）式でそれぞれ表される。
また、正常時のＴ相電圧Ｖ_T0の値｜Ｖ_T0｜、位相θ_T0および位相差β₀は（２１−１）式から（２１−３）式でそれぞれ表される（図１９（ａ）参照）。
｜Ｖ_T0｜＝１ （２１−１）
θ_T0＝２４０° （２１−２）
β₀＝θ_T0−θ_TR0＝２４０°−２１０°＝３０° （２１−３） (1) Composite current I _{(RS) 0} at normal time, TR phase line voltage V _TR0 and T phase voltage V _T0
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the above equations (1-1) to (1-5).
Further, the value of the T-phase voltage V _T0 at normal time | V _T0 |, the phase θ _T0, and the phase difference β ₀ are expressed by the equations (21-1) to (21-3), respectively (FIG. 19A) reference).
| V _T0 | = 1 (21-1)
θ _T0 = 240 ° (21-2)
β ₀ = θ _T0 −θ _TR0 = 240 ° −210 ° = 30 ° (21-3)

（２）過負荷時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
過負荷が発生して定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tが三相電源線のＲ相、Ｓ相およびＴ相にそれぞれ流れたとすると、過負荷時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRとは上記（２−１）式から（２−７）式でそれぞれ表される。
また、過負荷時のＴ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相変化角Δθ_Tは（２２−１）式から（２２−４）式でそれぞれ表される。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （２２−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （２２−２）
θ_T＝２４０° （２２−３）
Δθ_T＝θ_T−θ_T0＝２４０°−２４０°＝０° （２２−４） (2) Composite current I _RS at the time of overload, TR phase line voltage V _TR and T phase voltage V _T
R-phase, S-phase, and T-phase current 1.15 times the rated current value (in this example, normal R-phase, S-phase, and T-phase currents I _R0 , I _S0 , I _T0 ) due to overload I _R, I _S, R-phase of the I _T is a three-phase power line, assuming that respectively flow into S phase and T-phase, the value of the composite current I _RS during overload | I _RS |, the current change rate K _RS and phase The value of θ _RS and the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR , the phase θ _TR and the phase change angle Δθ _TR are expressed by the equations (2-1) to (2-7), respectively. expressed.
Further, the value of the T-phase voltage V _T at the time of overload | V _T |, the voltage change rate L _T , the phase θ _T and the phase change angle Δθ _T are respectively expressed by the equations (22-1) to (22-4). Is done.
| V _T | = | V _T0 | = 1 (22-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (22-2)
θ _T = 240 ° (22-3)
Δθ _T = θ _T −θ _T0 = 240 ° −240 ° = 0 ° (22-4)

（３）Ｒ−Ｓ相短絡時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
Ｒ相−Ｓ相間の短絡事故（Ｒ−Ｓ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＲ相およびＳ相事故電流Ｉ_FR，Ｉ_FSが流れたとすると、Ｒ−Ｓ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差α（＝θ_R-S−θ_TR）とは上記（３−１）式から（３−８）式でそれぞれ表される）。
また、Ｒ−Ｓ相短絡時のＴ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相変化角Δθ_Tは（２３−１）式から（２３−４）式でそれぞれ表される（図１８（ａ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （２３−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （２３−２）
θ_T＝２４０° （２３−３）
Δθ_T＝θ_T−θ_T0＝２４０°−２４０°＝０° （２３−４） (3) Composite current I _RS , TR phase line voltage V _TR and T phase voltage V _T when _RS phase is short-circuited
An R phase that is 1.15 times the rated current value (in this example, the normal R phase and S phase currents I _R0 , I _S0 ) due to a short circuit accident between the R phase and the S phase (R-S phase short circuit) And S-phase fault currents I _FR and I _FS flow, the value of the combined current I _RS when the _RS phase is short-circuited | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V _TR The value | V _TR |, the voltage change rate L _TR , the phase θ _{TR, the} phase change angle Δθ _TR, and the phase difference α (= θ _RS −θ _TR ) of the combined current I _RS are obtained from the above equation (3-1) ( 3-8) each represented by the formula).
Also, the value of the T-phase voltage V _T when the RS phase is short-circuited | V _T |, the voltage change rate L _T , the phase θ _T, and the phase change angle Δθ _T are expressed by the equations (23-1) to (23-4) (Refer to FIG. 18A).
| V _T | = | V _T0 | = 1 (23-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (23-2)
θ _T = 240 ° (23-3)
Δθ _T = θ _T −θ _T0 = 240 ° −240 ° = 0 ° (23-4)

（４）Ｓ−Ｔ相短絡時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
Ｓ相−Ｔ相間の短絡事故（Ｓ−Ｔ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは上記（４−１）式から（４−８）式でそれぞれ表される。
また、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-Sの位相差αとは上記（４−９）式から（４−１２）式でそれぞれ表される。
さらに、Ｓ−Ｔ相短絡時のＴ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相変化角Δθ_Tは（２４−１）式から（２４−４）式でそれぞれ表される（図１８（ｂ）参照）。
｜Ｖ_T｜＝｛０．５²＋（０．８×３^1/2／２）²｝^1/2 （２４−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝｛０．５²＋（０．８×３^1/2／２）²｝^1/2／１
（＝０．８５４） （２４−２）
θ_T＝２３４．２° （２４−３）
Δθ_T＝θ_T−θ_T0＝２３４．２°−２４０°＝−５．８° （２４−４） (4) Composite current I _RS , TR phase line voltage V _TR and T phase voltage V _T when S-T phase is short-circuited
The S phase is 1.15 times the rated current value (in this example, the normal R phase and S phase currents I _R0 , I _S0 ) due to the occurrence of a short circuit accident between the S phase and the T phase (ST phase short circuit) And T-phase fault currents I _FS and I _FT flow, the value | I _RS | of the combined current I _RS when the ST phase is short-circuited, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V _TR Value | V _TR |, voltage change rate L _TR , phase θ _TR, phase change angle Δθ _TR and phase difference α of the combined current I _RS are expressed by the equations (4-1) to (4-8), respectively. Is done.
Further, if the S-phase and T-phase fault currents I _FS and I _{FT that} are larger than the rated current value flow, the value | I _RS | of the combined current I _RS and the current change rate K _RS The phase difference α between the phase θ _RS and the combined current I _RS is expressed by the above equations (4-9) to (4-12), respectively.
Further, the value of the T-phase voltage V _T when the S-T phase is short-circuited | V _T |, the voltage change rate L _T , the phase θ _T, and the phase change angle Δθ _T are expressed by equations (24-1) to (24-4). (Refer to FIG. 18B).
| V _T | = {0.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (24-1)
L _T = | V _T | / | V _T0 | = {0.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 1
(= 0.854) (24-2)
θ _T = 234.2 ° (24-3)
Δθ _T = θ _T −θ _T0 = 234.2 ° −240 ° = −5.8 ° (24-4)

（５）Ｔ−Ｒ相短絡時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
Ｔ相−Ｒ相間の短絡事故（Ｔ−Ｒ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは上記（５−１）式から（５−８）式でそれぞれ表される。
また、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-Sの位相差αとは上記（５−９）式から（５−１２）式でそれぞれ表される。
さらに、Ｔ−Ｒ相短絡時のＴ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相変化角Δθ_Tは（２５−１）式から（２５−４）式でそれぞれ表される（図１８（ｃ）参照）。
｜Ｖ_T｜＝｛０．５²＋（０．８×３^1/2／２）²｝^1/2 （２５−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝｛０．５²＋（０．８×３^1/2／２）²｝^1/2／１
（＝０．８５４） （２５−２）
θ_T＝２４５．８° （２５−３）
Δθ_T＝θ_T−θ_T0＝２４５．８°−２４０°＝５．８° （２５−４） (5) Composite current I _RS , TR phase line voltage V _TR and T phase voltage V _T when T-R phase is short-circuited
A T-phase that is 1.15 times the rated current value (in this example, the R-phase and S-phase currents I _R0 and I _{S0 in} the normal state) due to a short-circuit accident between the T-phase and R-phase (T-R phase short-circuit) And R-phase fault currents I _FT and I _FR flow, the value of the combined current I _RS when the TR phase is short-circuited | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V _TR Value | V _TR |, voltage change rate L _TR , phase θ _TR, phase change angle Δθ _TR and phase difference α of the combined current I _RS are expressed by the above equations (5-1) to (5-8), respectively. Is done.
Also, assuming that the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow, the value of the combined current I _RS when the TR phase is short-circuited | I _RS |, the current change rate K _RS and The phase θ _RS and the phase difference α between the combined currents I _RS are expressed by the above equations (5-9) to (5-12), respectively.
Further, the value of the T-phase voltage V _T when the T-R phase is short-circuited | V _T |, the voltage change rate L _T , the phase θ _T, and the phase change angle Δθ _T are expressed by equations (25-1) to (25-4). (Refer to FIG. 18C).
| V _T | = {0.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (25-1)
L _T = | V _T | / | V _T0 | = {0.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 1
(= 0.854) (25-2)
θ _T = 245.8 ° (25-3)
Δθ _T = θ _T −θ _T0 = 245.8 ° -240 ° = 5.8 ° (25-4)

（６）三相短絡時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
三相短絡事故（三相短絡）が発生して定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相事故電流Ｉ_FR，Ｉ_FS，Ｉ_FTが流れたとすると、三相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TR、位相θ_TRおよび位相変化角Δθ_TRと合成電流Ｉ_R-Sの位相差αとは上記（６−１）式から（６−８）式でそれぞれ表される。
また、三相短絡時のＴ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相変化角Δθ_Tは（２６−１）式から（２６−４）式でそれぞれ表される（図１８（ｄ）参照）。
｜Ｖ_T｜＝０．８×｜Ｖ_T0｜＝０．８×１＝０．８ （２６−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝０．８／１＝０．８ （２６−２）
θ_T＝２４０° （２６−３）
Δθ_T＝θ_T−θ_T0＝２４０°−２４０°＝０° （２６−４） (6) Composite current I _RS , TR phase line voltage V _TR and T phase voltage V _T at the time of three-phase short circuit
R phase that is 1.15 times the rated current value (in this example, normal R phase, S phase, and T phase currents I _R0 , I _S0 , I _T0 ) due to the occurrence of a three-phase short circuit accident (three-phase short circuit) , S-phase and T-phase fault currents I _FR , I _FS , I _FT flow, value of composite current I _RS at three-phase short circuit | I _RS |, current change rate K _RS and phase θ _RS and TR phase line The value of the inter-voltage V _TR | V _TR |, the voltage change rate L _TR , the phase θ _{TR, the} phase change angle Δθ _TR and the phase difference α of the combined current I _RS are expressed by the above equation (6-1) (6-8) Each is represented by a formula.
Also, the value of the T-phase voltage V _T at the time of a three-phase short circuit | V _T |, the voltage change rate L _T , the phase θ _T and the phase change angle Δθ _T are expressed by the equations (26-1) to (26-4), respectively. It is expressed (see FIG. 18D).
| V _T | = 0.8 × | V _T0 | = 0.8 × 1 = 0.8 (26-1)
_{L T = | V T | /} | V T0 | = 0.8 / 1 = 0.8 (26-2)
θ _T = 240 ° (26-3)
Δθ _T = θ _T −θ _T0 = 240 ° −240 ° = 0 ° (26-4)

（７）過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出
合成電流Ｉ_R-Sの位相θ_R-Sがアーク抵抗の影響により−４５°〜１５°の範囲で変動することを考慮する。
（ａ）過負荷の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が所定の過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が所定の第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）よりも大きいと、「過負荷が発生した」と判定する。
（ｂ）Ｒ−Ｓ相短絡の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．３２８）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で所定の第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝５．２°）が第１の過負荷・短絡検出位相変化角範囲（たとえば、５．２°〜３０°（短絡点までのインピーダンスを考慮））内の値であると、「Ｒ−Ｓ相短絡が発生した」と判定する。
（ｃ）Ｓ−Ｔ相短絡の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．２３１）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝−５．２°）が第２の過負荷・短絡検出位相変化角範囲（たとえば、−５．２°〜−３０°）内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
また、３Ｅリレー５０は、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であっても、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝０．８５４）が第３の過負荷・短絡検出電圧変化率値（たとえば、０．８６）以下であり、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．９５４）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TR（＝−５．２°）が第２の過負荷・短絡検出位相変化角範囲（たとえば、−５．２°〜−３０°）内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
（ｄ）Ｔ−Ｒ相短絡の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．１８３）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であり、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝０．８５４）が第３の過負荷・短絡検出電圧変化率値（たとえば、０．８６）以下であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、Ｔ相電圧Ｖ_Tの位相変化角Δθ_T（＝５．８°）が第３の過負荷・短絡検出位相変化角範囲（たとえば、５．８°〜６０°）内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する。
また、３Ｅリレー５０は、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であっても、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、Ｔ相電圧Ｖ_Tの位相変化率Δθ_T（＝５．８°）が第３の過負荷・短絡検出位相変化角範囲（たとえば、５．８〜６０°）内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する。
（ｅ）三相短絡の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、Ｔ相電圧Ｖ_Tの位相変化率Δθ_T（＝０°）が第３の過負荷・短絡検出位相変化角範囲（たとえば、５．８〜６０°）内の値でないと、「三相短絡が発生した」と判定する。 (7) overload, RS-phase short circuit, S-T phase short-circuit, T-R phase short-circuit and three-phase short circuit detecting the resultant current I _RS phase theta _RS is -45 ° to 15 ° due to the influence of the arc resistance Consider fluctuations in range.
(A) Overload detection In the 3E relay 50, the current change rate K _RS (= 1.15) of the combined current I _RS is equal to or greater than a predetermined overload / short-circuit detection current change rate value (eg, 1.15). When the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is larger than a predetermined first overload / short-circuit detection voltage change rate value (for example, 0.96), Is determined to occur.
(B) Detection of R-S phase short circuit The 3E relay 50 has a current change rate K _RS (= 1.328) of the combined current I _RS that is equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15). Yes, and the voltage change rate L _TR (= 0.954) of the TR phase line voltage V _TR is equal to or less than a first overload / short-circuit detection voltage change rate value (for example, 0.96) The overload / short circuit detection voltage change rate value (for example, 0.8) is larger and the phase change angle Δθ _TR (= 5.2 °) of the TR phase line voltage V _TR is the first overload / short circuit. If it is a value within the detection phase change angle range (for example, 5.2 ° to 30 ° (considering impedance to the short circuit point)), it is determined that “the R-S phase short circuit has occurred”.
(C) Detection of S-T phase short circuit The 3E relay 50 has a current change rate K _RS (= 1.231) of the combined current I _RS equal to or higher than an overload / short circuit detection current change rate value (eg, 1.15). There, and the voltage change rate L _T (= 0.954) is the first overload or short circuit detecting voltage change rate value of the T-phase voltage V _T (e.g., 0.96) the second overload or short circuit in the following The phase change angle Δθ _TR (= −5.2 °) of the TR phase line voltage V _TR is larger than the detection voltage change rate value (for example, 0.8), and the second overload / short-circuit detection phase change When the value is within the angular range (for example, −5.2 ° to −30 °), it is determined that “S-T phase short circuit has occurred”.
Further, the 3E relay 50 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the S-phase and T-phase fault currents I _FS , I _FT exceeding the rated current value flow. Is less than the overload / short-circuit detection current change rate value (eg, 1.15), the voltage change rate L _T (= 0.854) of the T-phase voltage V _T is the third overload / short-circuit detection voltage. The change rate value (eg, 0.86) or less, and the voltage change rate L _TR (= 0.954) of the TR phase line voltage V _TR is equal to the second overload / short-circuit detection voltage change rate value (eg, 0 .8) and the phase change angle Δθ _TR (= −5.2 °) of the TR phase line voltage V _TR is equal to the second overload / short-circuit detection phase change angle range (for example, −5.2). When the value is within the range of (° to −30 °), it is determined that “ST phase short circuit has occurred”.
(D) Detection of TR phase short circuit The 3E relay 50 has a current change rate K _RS (= 0.183) of the combined current I _RS that is less than the overload / short circuit detection current change rate value (eg, 1.15). Yes, and the voltage change rate L _T (= 0.854) of the T-phase voltage V _T is equal to or less than a third overload / short-circuit detection voltage change rate value (for example, 0.86), and the TR phase wire The voltage change rate L _TR (= 0.8) of the inter-voltage V _TR is equal to or less than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and the phase change angle Δθ of the T-phase voltage V _{T When T} (= 5.8 °) is a value within the third overload / short-circuit detection phase change angle range (for example, 5.8 ° to 60 °), “T-R phase short-circuit has occurred” judge.
Further, the 3E relay 50 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow. Is the overload / short circuit detection current change rate value (eg, 1.15) or more, the voltage change rate L _TR (= 0.8) of the TR phase line voltage V _TR is the second overload / short circuit The phase change rate Δθ _T (= 5.8 °) of the T-phase voltage V _T is equal to or less than the detected voltage change rate value (for example, 0.8), and the third overload / short-circuit detected phase change angle range ( For example, when the value is within the range of 5.8 to 60 °, it is determined that “T-R phase short circuit has occurred”.
(E) Three-phase short circuit detection The 3E relay 50 has a current change rate K _RS (= 1.15) of the combined current I _RS equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15), The voltage change rate L _TR (= 0.8) of the TR phase line voltage V _TR is equal to or less than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and the T phase voltage If the phase change rate Δθ _T (= 0 °) of V _T is not a value within the third overload / short-circuit detection phase change angle range (for example, 5.8 to 60 °), “a three-phase short circuit has occurred” Is determined.

次に、３Ｅリレー５０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について、図１９を参照して詳しく説明する。   Next, a method for detecting the RS reciprocal phase, the ST reciprocal phase, and the TR reciprocal phase in the 3E relay 50 will be described in detail with reference to FIG.

（１）正常時の合成電流Ｉ_(R-S)0、ＴＲ相線間電圧Ｖ_TR0およびＴ相電圧Ｖ_T0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0と正常時の合成電流Ｉ_(R-S)0の位相差α₀とは上記（１−１）式から（１−５）式でそれぞれ表される。
また、正常時のＴ相電圧Ｖ_T0の値｜Ｖ_T0｜、位相θ_T0および位相差β₀は上記（２１−１）式から上記（２１−３）式でそれぞれ表される（図１９（ａ）参照）。 (1) Composite current I _{(RS) 0} at normal time, TR phase line voltage V _TR0 and T phase voltage V _T0
Normal value of composite current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal value of TR phase line voltage V _TR0 | V _TR0 | and phase θ _TR0 and normal value The phase difference α ₀ of the combined current I _{(RS) 0} is expressed by the above equations (1-1) to (1-5).
Further, the value | V _T0 |, the phase θ _T0, and the phase difference β ₀ of the T-phase voltage V _{T0 in} the normal state are expressed by the above formula (21-1) to the above formula (21-3), respectively (FIG. 19 ( a)).

（２）Ｒ−Ｓ相反相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
三相電源線のＲ相およびＳ相が逆になる（Ｒ−Ｓ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは上記（７−１）式から（７−６）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相差βは（２７−１）式から（２７−４）式でそれぞれ表される（図１９（ｂ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （２７−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （２７−２）
θ_T＝２４０° （２７−３）
β＝θ_T−θ_TR＝２４０°−２７０°＝−３０° （２７−４） (2) Composite current I _RS , TR phase line voltage V _TR and T phase voltage V _T during the R-S phase opposite phase
When the R phase and S phase of the three-phase power supply line are reversed (R-S phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V The value of _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (7-1) to (7-6), respectively.
Further, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T , the phase θ _T and the phase difference β are expressed by the equations (27-1) to (27-4), respectively (FIG. 19 ( b)).
| V _T | = | V _T0 | = 1 (27-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (27-2)
θ _T = 240 ° (27-3)
β = θ _T −θ _TR = 240 ° -270 ° = −30 ° (27-4)

（３）Ｓ−Ｔ相反相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
三相電源線のＳ相およびＴ相が逆になる（Ｓ−Ｔ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは上記（８−１）式から（８−６）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相差βは（２８−１）式から（２８−４）式でそれぞれ表される（図１９（ｃ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （２８−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （２８−２）
θ_T＝１２０° （２８−３）
β＝θ_T−θ_TR＝１２０°−１５０°＝−３０° （２８−４） (3) Combined current I _RS , TR phase line voltage V _TR and T phase voltage V _T during S-T phase reciprocal phase
When the S phase and T phase of the three-phase power supply line are reversed (ST phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V The value of _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the equations (8-1) to (8-6), respectively.
Further, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T , the phase θ _T and the phase difference β are expressed by the equations (28-1) to (28-4), respectively (FIG. 19 ( c)).
| V _T | = | V _T0 | = 1 (28-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (28-2)
θ _T = 120 ° (28-3)
β = θ _T −θ _TR = 120 ° −150 ° = −30 ° (28-4)

（４）Ｔ−Ｒ相反相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_T
三相電源線のＴ相およびＲ相が逆になる（Ｔ−Ｒ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは（１０−１）式から（１０−６）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_T、位相θ_Tおよび位相差βは（２９−１）式から（２９−４）式でそれぞれ表される（図１９（ｄ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （２９−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （２９−２）
θ_T＝０° （２９−３）
β＝θ_T−θ_TR＝０°−３０°＝−３０° （２９−４） (4) Combined current I _RS , TR phase line voltage V _TR and T phase voltage V _T during the TR phase opposite phase
When the T phase and R phase of the three-phase power supply line are reversed (TR phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the TR phase line voltage V The value of _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by equations (10-1) to (10-6), respectively.
Also, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T , the phase θ _T and the phase difference β are respectively expressed by the equations (29-1) to (29-4) (FIG. 19 ( d)).
| V _T | = | V _T0 | = 1 (29-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (29-2)
θ _T = 0 ° (29-3)
β = θ _T −θ _TR = 0 ° −30 ° = −30 ° (29-4)

（５）反相の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が所定の反相検出電流変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が所定の反相検出電圧変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝１）が反相検出電圧変化率範囲内の値であり、かつ、Ｔ相電圧Ｖ_Tの位相差β（＝−３０°）が所定の反相検出位相差範囲（たとえば、−６０°〜０°）内の値であると、「反相が発生した」と判定する。 (5) Detection of opposite phase In the 3E relay 50, the current change rate K _RS (= 1) of the combined current I _RS is a value within a predetermined opposite phase detection current change rate range (for example, 0.9 to 1.1). And the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is a value within a predetermined antiphase detection voltage change rate range (for example, 0.9 to 1.1), and , the voltage change rate of the T-phase voltage V _T L _T (= 1) is a value in the anti-phase detection voltage change rate range, and the phase difference between the T-phase voltage _{V T β (= - 30 °} ) is given If the value is within the anti-phase detection phase difference range (for example, −60 ° to 0 °), it is determined that “an anti-phase has occurred”.

次に、３Ｅリレー５０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について、図２０を参照して詳しく説明する。   Next, FIG. 20 shows a method for detecting the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase breaks of the star-connected three-phase power supply line in the 3E relay 50. This will be described in detail with reference.

（１）正常時の合成電流Ｉ_(R-S)0、ＴＲ相線間電圧Ｖ_TR0およびＴ相電流Ｉ_T0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0とＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは上記（１−１）式から（１−４）式でそれぞれ表される。
また、正常時のＴ相電圧Ｖ_T0の値｜Ｖ_T0｜および位相θ_T0とは上記（２１−１）式および（２１−２）式でそれぞれ表される。 (1) Composite current I _{(RS) 0} at normal time, TR phase line voltage V _TR0 and T phase current I _T0
Combined current I _{(RS) 0} value at normal | I _{(RS) 0} | and phase θ _{(RS) 0} and the value of TR-phase line voltage V _TR0 | V _TR0 | and above the phase theta _TR0 (1- 1) to (1-4).
Further, the value | V _T0 | and the phase θ _T0 of the T-phase voltage V _{T0 in} the normal state are expressed by the above expressions (21-1) and (21-2), respectively.

（２）Ｒ相欠相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＲ相の欠相（Ｒ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは上記（１０−１）式から（１０−７）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは（３０−１）式から（３０−３）式でそれぞれ表される（図２０（ａ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜×ｃｏｓ３０°＝１×（３^1/2／２）＝３^1/2／２ （３０−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝（３^1/2／２）／１＝３^1/2／２
（＝０．８６６） （３０−２）
θ_T＝２７０° （３０−３） (2) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when R phase is open
When an R-phase phase loss (R-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the phase difference α of the combined current I _RS are expressed by the above equations (10-1) to (10-7), respectively.
Further, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T, and the phase θ _TR are expressed by the equations (30-1) to (30-3), respectively (see FIG. 20A). .
| V _T | = | V _T0 | × cos 30 ° = 1 × (3 ^1/2 / 2) = 3 ^1/2 / 2 (30-1)
L _T = | V _T | / | V _T0 | = (3 ^1/2 / 2) / 1 = 3 ^1/2 / 2
(= 0.866) (30-2)
θ _T = 270 ° (30-3)

（３）Ｓ相欠相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＳ相の欠相（Ｓ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは上記（１１−１）式から（１１−７）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは（３１−１）式から（３１−３）式でそれぞれ表される（図２０（ｂ）参照）。
｜Ｖ_T｜＝｜Ｖ_T0｜×ｃｏｓ３０°＝１×（３^1/2／２）＝３^1/2／２ （３１−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝（３^1/2／２）／１＝３^1/2／２
（＝０．８６６） （３１−２）
θ_T＝２１０° （３０−３） (3) Combined current I _RS , TR phase line voltage V _TR and T phase current I _T when S phase is open
When the S-phase phase loss (S-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the phase difference α of the combined current I _RS are expressed by the equations (11-1) to (11-7), respectively.
Further, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T, and the phase θ _TR are expressed by equations (31-1) to (31-3), respectively (see FIG. 20B). .
| V _T | = | V _T0 | × cos 30 ° = 1 × (3 ^1/2 / 2) = 3 ^1/2 / 2 (31-1)
L _T = | V _T | / | V _T0 | = (3 ^1/2 / 2) / 1 = 3 ^1/2 / 2
(= 0.866) (31-2)
θ _T = 210 ° (30-3)

（４）Ｔ相欠相時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＴ相の欠相（Ｔ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-Sの位相差αとは上記（１２−１）式から（１２−７）式でそれぞれ表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは（３２−１）式から（３２−３）式でそれぞれ表される（図２０（ｃ）参照）。
｜Ｖ_T｜＝０ （３２−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝０／１＝０ （３２−２）
θ_T＝２４０° （３２−３） (4) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when T phase is open
When a T-phase phase loss (T-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the phase difference α of the combined current I _RS are expressed by the equations (12-1) to (12-7), respectively.
Further, the value | V _T | of the T-phase voltage V _T , the voltage change rate L _T, and the phase θ _TR are expressed by the equations (32-1) to (32-3), respectively (see FIG. 20C). .
| V _T | = 0 (32-1)
L _T = | V _T | / | V _T0 | = 0/1 = 0 (32-2)
θ _T = 240 ° (32-3)

（５）Ｒ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＲ相の断線（Ｒ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１０−１）式から（１０−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１３−１）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは（３３−１）式から（３３−３）式でそれぞれ表される。
｜Ｖ_T｜＝｜Ｖ_T0｜＝１ （３３−１）
Ｌ_T＝｜Ｖ_T｜／｜Ｖ_T0｜＝１／１＝１ （３３−２）
θ_T＝２４０° （３３−３） (5) Combined current I _RS , TR phase line voltage V _TR and T phase current I _T when R phase is broken
When the R-phase disconnection (R-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (10-1) (10− 3), the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. The phase difference α of the combined current I _RS is expressed by the above equation (13-1).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR is respectively represented by (33-3) expression (33-1) below.
| V _T | = | V _T0 | = 1 (33-1)
L _T = | V _T | / | V _T0 | = 1/1 = 1 (33-2)
θ _T = 240 ° (33-3)

（６）Ｓ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＳ相の断線（Ｓ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１１−１）式から（１１−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１３−２）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは上記（３３−１）式から（３３−３）式でそれぞれ表される。 (6) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when S phase is broken
When the S-phase disconnection (S-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (11-1) as (11− 3), and the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. The phase difference α of the combined current I _RS is expressed by the above equation (13-2).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR are represented respectively by the above (33-1) Formula (33-3) below.

（７）Ｔ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＴ相の断線（Ｔ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１２−１）式から（１２−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１３−３）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは上記（３３−１）式から（３３−３）式でそれぞれ表される。 (7) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when T phase is broken
When the T-phase disconnection (T-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (12-1) as (12− 3), the value of the TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively. The phase difference α of the combined current I _RS is expressed by the above equation (13-3).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR are represented respectively by the above (33-1) Formula (33-3) below.

（８）Ｒ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出
（ａ）Ｒ相欠相の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が所定の欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が所定の第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、合成電流Ｉ_R-Sの位相差α（＝０°）が所定の第１の欠相検出位相差範囲（たとえば、−３０°〜３０°）内の値であると、「Ｒ相欠相が発生した」と判定する。
（ｂ）Ｓ相欠相の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝０．８６６）が第２の欠相・断線検出電圧変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、合成電流Ｉ_R-Sの位相差α（＝１８０°）が所定の第２の欠相検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｓ相欠相が発生した」と判定する。
（ｃ）Ｔ相欠相の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝０）が所定の欠相検出電圧変化率値（たとえば、０．１）以下であり、かつ、合成電流Ｉ_R-Sの位相差α（＝１８０°）が第２の欠相検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｔ相欠相が発生した」と判定する。
（ｄ）Ｒ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、ＴＲ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝１）が第２の欠相・断線検出電圧変化率範囲（たとえば、０．８〜０．９）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝６０°）が所定の第１の断線検出位相差範囲（たとえば、３０°〜９０°）内の値であると、「Ｒ相断線が発生した」と判定する。
（ｅ）Ｓ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_T（＝１）が第２の欠相・断線検出電圧変化率範囲（たとえば、０．８〜０．９）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１８０°）が所定の第２の断線検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｓ相断線が発生した」と判定する。
（ｆ）Ｔ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が欠相・断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１２０°）が所定の第３断線検出位相差範囲（たとえば、９０°〜１５０°）内の値であると、「Ｔ相断線が発生した」と判定する。 (8) R Aiketsusho, S Aiketsusho, T Aiketsusho, detection 3E relay 50 of the R-phase disconnection, S-phase disconnection and T-phase detection of disconnection (a) R-phase open-phase is the combined current I _RS The current change rate K _RS (= 0.5) is a value within a predetermined open phase / disconnection detection current change rate range (for example, 0.4 to 0.6), and the TR phase line voltage V _TR The voltage change rate L _TR (= 0.5) is a value within a predetermined first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the combined current I _RS When the phase difference α (= 0 °) is a value within a predetermined first phase loss detection phase difference range (for example, −30 ° to 30 °), it is determined that “R phase phase loss has occurred”.
(B) Detection of S-phase phase loss The 3E relay 50 has a current rate of change K _RS (= 0.5) of the combined current I _{RS in} the range of phase failure / disconnection detection current change rate (eg, 0.4 to 0.6 ), And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is in the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the voltage change rate L _T (= 0.866) of the T-phase voltage V _T is within the second open-phase / disconnection detection voltage change rate range (for example, 0.8 to 0.9). And the phase difference α (= 180 °) of the combined current I _RS is a value within a predetermined second phase loss detection phase difference range (for example, 150 ° to 210 °). It is determined that a phase failure has occurred.
(C) Detection of T-phase phase loss In the 3E relay 50, the current change rate K _RS (= 1) of the combined current I _RS is within the range of the phase failure / disconnection detection current change rate (for example, 0.4 to 0.6). And the voltage change rate L _TR (= 0.5) of the TR phase line-to-line voltage V _TR is in the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the voltage change rate L _T (= 0) of the T-phase voltage V _T is equal to or less than a predetermined open-phase detection voltage change rate value (for example, 0.1), and the combined current I _RS When the phase difference α (= 180 °) is a value within the second phase loss detection phase difference range (for example, 150 ° to 210 °), it is determined that “T phase phase loss has occurred”.
(D) detecting 3E relay 50 of the R-phase disconnection, combined current I _RS of the current rate of change K _RS (= 0.5) is open phase-disconnection detecting the current change rate range (e.g., 0.4-0.6) And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is within the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the voltage change rate L _T (= 1) of the TR phase voltage V _T is a value within the second open phase / disconnection detection voltage change rate range (for example, 0.8 to 0.9). If the phase difference α (= 60 °) of the combined current I _RS is a value within a predetermined first disconnection detection phase difference range (for example, 30 ° to 90 °), “R phase disconnection occurs. It was determined.
(E) Detection of S-phase disconnection In the 3E relay 50, the current change rate K _RS (= 0.5) of the combined current I _{RS is in} the range of open-phase / disconnection detection current change rate (for example, 0.4 to 0.6). And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is within the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the voltage change rate L _T (= 1) of the T-phase voltage V _T is a value within the second open-phase / disconnection detection voltage change rate range (for example, 0.8 to 0.9). If the phase difference α (= 180 °) of the combined current I _RS is a value within a predetermined second disconnection detection phase difference range (for example, 150 ° to 210 °), “S phase disconnection occurs. It was determined.
(F) Detection of T-phase disconnection In the 3E relay 50, the current change rate K _RS (= 1) of the combined current I _RS is within the phase loss / disconnection detection current change rate range (for example, 0.4 to 0.6). And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is a value within the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). not, and the phase difference α (= 120 °) is predetermined third disconnection detecting phase difference range of the combined current I _RS (e.g., 90 ° ~150 °) when a value within the "T-phase disconnection occurs It was determined.

次に、３Ｅリレー２０におけるデルタ結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出方法について詳しく説明する。   Next, a method for detecting the R-phase, S-phase, T-phase, RS-phase, ST-phase, and TR-phase disconnections of the three-phase power supply line connected in delta connection in the 3E relay 20 will be described in detail.

（１）正常時の合成電流Ｉ_(R-S)0、ＴＲ相線間電圧Ｖ_TR0およびＴ相電流Ｉ_T0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0とＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは上記（１−１）式から（１−４）式でそれぞれ表される。 (1) Composite current I _{(RS) 0} at normal time, TR phase line voltage V _TR0 and T phase current I _T0
Combined current I _{(RS) 0} value at normal | I _{(RS) 0} | and phase θ _{(RS) 0} and the value of TR-phase line voltage V _TR0 | V _TR0 | and above the phase theta _TR0 (1- 1) to (1-4).

（２）Ｒ相欠相、Ｓ相欠相およびＴ相欠相の検出
３Ｅリレー５０は、上述したスター結線された三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相の検出と同様にして、三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相を検出する。 (2) Detection of R-phase, S-phase, and T-phase missing phases The 3E relay 50 detects the R-phase, S-phase, and T-phase missing phases of the star-connected three-phase power supply line. Similarly to the detection, the R-phase missing phase, the S-phase missing phase, and the T-phase missing phase of the three-phase power supply line are detected.

（３）ＲＳ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＲＳ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１４−１）式から（１４−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１４−４）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは上記（３３−１）式から（３３−３）式でそれぞれ表される。 (3) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when RS phase is disconnected
When the RS phase disconnection of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are expressed by the above equations (14-1) to (14-3), respectively. is the value of the voltage V _TR - TR phase line | V _TR |, the voltage change rate L _TR and the phase theta _TR each represented by (2-6) below from the above (2-4) equation, the composite current I _RS The phase difference α is expressed by the above equation (14-4).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR are represented respectively by the above (33-1) Formula (33-3) below.

（４）ＳＴ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＳＴ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１５−１）式から（１５−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１５−４）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは上記（３３−１）式から（３３−３）式でそれぞれ表される。 (4) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when ST phase is disconnected
When the ST phase disconnection of the three-phase power line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are expressed by the above equations (15-1) to (15-3), respectively. is the value of the voltage V _TR - TR phase line | V _TR |, the voltage change rate L _TR and the phase theta _TR each represented by (2-6) below from the above (2-4) equation, the composite current I _RS The phase difference α is expressed by the above equation (15-4).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR are represented respectively by the above (33-1) Formula (33-3) below.

（４）ＴＲ相断線時の合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電流Ｉ_T
三相電源線のＴＲ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１６−１）式から（１６−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表され、合成電流Ｉ_R-Sの位相差αは上記（１６−４）式で表される。
また、Ｔ相電圧Ｖ_Tの値｜Ｖ_T｜、電圧変化率Ｌ_Tおよび位相θ_TRは上記（３３−１）式から（３３−３）式でそれぞれ表される。 (4) Composite current I _RS , TR phase line voltage V _TR and T phase current I _T when TR phase is disconnected
When the TR phase disconnection of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by the above equations (16-1) to (16-3), respectively. is the value of the voltage V _TR - TR phase line | V _TR |, the voltage change rate L _TR and the phase theta _TR each represented by (2-6) below from the above (2-4) equation, the composite current I _RS The phase difference α is expressed by the above equation (16-4).
The value of T-phase voltage V _T | V _T |, the voltage change rate L _T and the phase theta _TR are represented respectively by the above (33-1) Formula (33-3) below.

（５）ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出
（ａ）ＲＳ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．３３３）が所定の第１の断線検出電流変化率範囲（たとえば、０．２〜０．４）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でないと、「ＲＳ相断線が発生した」と判定する。
（ｂ）ＳＴ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が所定の第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１３９．１°）が所定の第４の断線検出位相差範囲（たとえば、１３０°〜１５０°）内の値であると、「ＳＴ相断線が発生した」と判定する。
（ｃ）ＴＲ相断線の検出
３Ｅリレー５０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）が第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの位相差α（＝１００．９°）が所定の第５の断線検出位相差範囲（たとえば、９０°〜１１０°）内の値であると、「ＴＲ相断線が発生した」と判定する。 (5) Detection of RS phase disconnection, ST phase disconnection, and TR phase disconnection (a) Detection of RS phase disconnection The 3E relay 50 has a predetermined current change rate K _RS (= 0.333) of the combined current I _RS . Is a value within the disconnection detection current change rate range (for example, 0.2 to 0.4), and the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is If it is not a value within the disconnection detection voltage change rate range (for example, 0.4 to 0.6), it is determined that “RS phase disconnection has occurred”.
(B) Detection of ST phase disconnection In the 3E relay 50, the current change rate K _RS (= 0.882) of the combined current I _RS has a predetermined second disconnection detection current change rate range (for example, 0.8 to 0. 9), and the voltage change rate L _TR (= 1) of the TR phase line voltage V _TR is within the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). ) And the phase difference α (= 139.1 °) of the combined current I _RS is a value within a predetermined fourth disconnection detection phase difference range (for example, 130 ° to 150 °). , “ST phase disconnection has occurred” is determined.
(C) Detection of TR phase disconnection In the 3E relay 50, the current change rate K _RS (= 0.882) of the combined current I _RS has a second disconnection detection current change rate range (for example, 0.8 to 0.9). And the voltage change rate L _TR (= 1) of the TR phase line-to-line voltage V _TR is within the first open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6). And the phase difference α (= 100.9 °) of the combined current I _RS is a value within a predetermined fifth disconnection detection phase difference range (for example, 90 ° to 110 °). It is determined that a TR phase disconnection has occurred.

次に、３Ｅリレー５０の構成について、図２１を参照して説明する。
３Ｅリレー５０は、図２１に示すように、入力変換器５１と、アナログ入力部５２と、メモリ５３と、電流変化率算出部５４と、電圧変化率算出部５５と、位相角算出部５６と、位相差算出部５７と、リレー演算処理部５８と、整定・表示部５９と、入出力部６０と、外部機器Ｉ／Ｆ部６１とを備える。 Next, the configuration of the 3E relay 50 will be described with reference to FIG.
As shown in FIG. 21, the 3E relay 50 includes an input converter 51, an analog input unit 52, a memory 53, a current change rate calculation unit 54, a voltage change rate calculation unit 55, and a phase angle calculation unit 56. , A phase difference calculation unit 57, a relay calculation processing unit 58, a settling / display unit 59, an input / output unit 60, and an external device I / F unit 61.

ここで、入力変換器５１は、クロス貫通変流器４１から入力される合成電流Ｉ_R-Sおよび計器用変成器４２から入力されるＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tのレベルをアナログ入力部５２の処理に適したレベルに変換する。
アナログ入力部５２は、バンドパスフィルタとサンプリングホールド回路とマルチプレクサ回路とアナログ／ディジタル変換器とを備え、入力変換器５１から入力されるアナログの合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tをディジタルの合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tに変換する。
メモリ５３は、アナログ入力部５２によってディジタルデータに変換された合成電流Ｉ_R-S、ＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tを格納するためのものである。 Here, the input converter 51 analogizes the levels of the combined current I _RS input from the cross-through current transformer 41 and the TR phase line voltage V _TR and T phase voltage V _T input from the instrument transformer 42. The level is converted to a level suitable for the processing of the input unit 52.
Analog input unit 52 is provided with a band-pass filter and a sampling hold circuit and multiplexer circuit and an analog / digital converter, the combined current of the analog input from the input transducer 51 I _RS, between TR-phase line voltage V _TR and T The phase voltage V _T is converted into a digital composite current I _RS , a TR phase line voltage V _TR and a T phase voltage V _T.
The memory 53 is for storing the combined current I _RS , the TR phase line voltage V _TR and the T phase voltage V _T converted into digital data by the analog input unit 52.

電流変化率算出部５４は、メモリ５３に格納されているＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値に基づいて、アナログ入力部５２から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sを算出する。 The current change rate calculation unit 54 is a composite current input from the analog input unit 52 based on the rated current values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T stored in the memory 53. calculating a current change rate K _RS of I _RS.

電圧変化率算出部５５は、メモリ５３に格納されているＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値に基づいて、アナログ入力部５２から入力されるＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tの電圧変化率Ｌ_TR，Ｌ_Tを算出する。 The voltage change rate calculation unit 55 receives the TR phase input from the analog input unit 52 based on the rated voltage values of the R phase, S phase, and T phase voltages V _R , V _S , and V _T stored in the memory 53. voltage change rate L _TR line voltage V _TR and T-phase voltage V _T, and calculates the L _T.

位相変化角算出部５６と、アナログ入力部５２から入力されるＴＲ相線間電圧Ｖ_TRの位相θ_TRからメモリ５３に格納されている正常時のＴＲ相線間電圧Ｖ_TRの位相θ_TR0を引くことによりＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRを算出するとともに、アナログ入力部５２から入力されるＴ相電圧Ｖ_Tの位相θ_Tからメモリ５３に格納されている正常時のＴ相電圧Ｖ_Tの位相θ_T0を引くことによりＴ相電圧Ｖ_Tの位相変化角Δθ_Tを算出する。 From the phase θ _{TR of the} TR phase line voltage V _TR input from the phase change angle calculation unit 56 and the analog input unit 52, the phase θ _TR0 of the TR phase line voltage V _TR at normal time stored in the memory 53 is obtained. The phase change angle Δθ _TR of the TR phase line voltage V _TR is calculated by subtraction, and the normal T stored in the memory 53 from the phase θ _T of the T phase voltage V _T input from the analog input unit 52. calculating a phase change angle [Delta] [theta] _T T-phase voltage V _T by subtracting the phase theta _T0 of the phase voltage V _T.

位相差算出部５７は、アナログ入力部５２から入力される合成電流Ｉ_R-Sの位相θ_R-Sからアナログ入力部５２から入力されるＴＲ相線間電圧Ｖ_TRの位相θ_TRを引くことにより、合成電流Ｉ_R-Sの位相差αを算出するとともに、アナログ入力部５２から入力されるＴ相電圧Ｖ_Tの位相θ_TからＴＲ相線間電圧Ｖ_TRの位相θ_TRを引くことにより、Ｔ相電圧Ｖ_Tの位相差βを算出する。 The phase difference calculation unit 57 subtracts the phase θ _TR of the TR phase line voltage V _TR input from the analog input unit 52 from the phase θ _RS of the combined current I _RS input from the analog input unit 52, thereby generating the combined current. By calculating the phase difference α of I _RS and subtracting the phase θ _TR of the TR phase line voltage V _TR from the phase θ _T of the T phase voltage V _T input from the analog input unit 52, the T phase voltage V _T The phase difference β is calculated.

リレー演算処理部５８は、電流変化率算出部５４によって算出された合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sと電圧変化率算出部５５によって算出されたＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tの電圧変化率Ｌ_TR，Ｌ_Tと位相変化角算出部５６によって算出されたＴＲ相線間電圧Ｖ_TRおよびＴ相電圧Ｖ_Tの位相変化角Δθ_TR，Δθ_Tと位相差算出部５７によって算出された合成電流Ｉ_R-SおよびＴ相電圧Ｖ_Tの位相差α，βと基づいて、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡、三相短絡、Ｒ−Ｓ相反相、Ｓ−Ｔ相反相、Ｔ−Ｒ相反相、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線、Ｔ相断線、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出すると、第１乃至第３の遮断器３₁〜３₃（図１７参照）をそれぞれ遮断するための第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を生成し、生成した第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を入出力部６０および外部機器インターフェース部６１を介して第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The relay calculation processing unit 58 includes the current change rate K _RS of the combined current I _RS calculated by the current change rate calculating unit 54, the TR phase line voltage V _TR and the T phase voltage V calculated by the voltage change rate calculating unit 55. voltage change rate L _TR of _T, L _T and TR between phase line voltage is calculated by the phase change angle calculation unit 56 V _TR and T-phase voltage V _T of the phase change angle [Delta] [theta] _TR, by [Delta] [theta] _T and the phase difference calculator 57 Based on the calculated composite current I _RS and phase difference α, β of T phase voltage V _T , overload, RS phase short circuit, ST phase short circuit, TR phase short circuit, three phase short circuit, R− S-phase reciprocal phase, S-T reciprocal phase, TR reciprocal phase, R-phase open phase, S-phase open phase, T-phase open phase, R-phase open phase, S-phase open phase, T-phase R-phase open phase, S-phase open phase, T-phase open phase, RS phase open phase, ST phase open phase and T Upon detecting a phase disconnection, the first to the third circuit breakers 3 ₁ to 3 ₃ to generate the first to third trip signal T ₁ through T ₃ for blocking (see FIG. 17), respectively, were produced first The first to third trip signals T _{1 to} T ₃ are output to the first to third circuit breakers 3 ₁ to ₃ 3 via the input / output unit 60 and the external device interface unit 61, respectively.

整定・表示部５９は、過負荷・短絡検出電流変化率値、第１乃至第３の過負荷・短絡検出電圧変化率値、第１乃至第３の過負荷・短絡検出位相変化角範囲、第１および第２の過負荷・短絡検出位相差範囲、反相検出電流変化率範囲、反相検出電圧変化率範囲、反相検出位相差範囲、欠相・断線検出電流変化率範囲、第１および第２の断線検出電流変化率範囲、第１および第２の欠相・断線検出電圧変化率範囲、欠相検出電圧変化率値、第１および第２の欠相検出位相差範囲並びに第１乃至第５の断線検出位相差範囲に基づいてリレー整定処理を行うとともに、整定値などを外部に表示する。   The settling / display unit 59 includes an overload / short-circuit detection current change rate value, first to third overload / short-circuit detection voltage change rate values, first to third overload / short-circuit detection phase change angle ranges, 1 and 2 overload / short circuit detection phase difference range, anti-phase detection current change rate range, anti-phase detection voltage change rate range, anti-phase detection phase difference range, open phase / disconnection detection current change rate range, Second disconnection detection current change rate range, first and second open phase / disconnection detection voltage change rate range, open phase detection voltage change rate value, first and second open phase detection phase difference ranges, and first to second A relay settling process is performed based on the fifth disconnection detection phase difference range, and a settling value or the like is displayed outside.

次に、以下に示す条件下におけるリレー演算処理部５８の動作について説明する。
（１）過負荷・短絡検出電流変化率値＝１．１５、第１の過負荷・短絡検出電圧変化率値＝０．９６、第２の過負荷・短絡検出電圧変化率値＝０．８、第３の過負荷・短絡検出電圧変化率値＝０．８６、第１の過負荷・短絡検出位相変化角範囲＝５．２°〜３０°、第２の過負荷・短絡検出位相変化角範囲＝−５．２°〜−３０°、第３の過負荷・短絡検出位相変化角範囲＝５．８°〜６０°、第１の過負荷・短絡検出位相差範囲＝９５．２°〜１８０°、第２の過負荷・短絡検出位相差範囲＝−１５０°〜−９０°
（２）反相検出電流変化率範囲＝０．９〜１．１、反相検出電圧変化率範囲＝０．９〜１．１、反相検出位相差範囲＝−６０°〜０°
（３）欠相・断線検出電流変化率範囲＝０．４〜０．６、第１の断線検出電流変化率範囲＝０．２〜０．４、第２の断線検出電流変化率範囲＝０．８〜０．９、第１の欠相・断線検出電圧変化率範囲＝０．４〜０．６、第２の欠相・断線検出電圧変化率範囲＝０．８〜０．９、欠相検出電圧変化率値＝０．１、第１の欠相検出位相差範囲＝−３０°〜３０°、第２の欠相検出位相差範囲＝１５０°〜２１０°、第１の断線検出位相差範囲＝３０°〜９０°、第２の断線検出位相差範囲＝１５０°〜２１０°、第３断線検出位相差範囲＝９０°〜１５０°、第４の断線検出位相差範囲＝１３０°〜１５０°、第５の断線検出位相差範囲＝９０°〜１１０° Next, the operation of the relay calculation processing unit 58 under the following conditions will be described.
(1) Overload / short-circuit detection current change rate value = 1.15, first overload / short-circuit detection voltage change rate value = 0.96, second overload / short-circuit detection voltage change rate value = 0.8 , Third overload / short-circuit detection voltage change rate value = 0.86, first overload / short-circuit detection phase change angle range = 5.2 ° to 30 °, second overload / short-circuit detection phase change angle Range = −5.2 ° to −30 °, third overload / short-circuit detection phase change angle range = 5.8 ° to 60 °, first overload / short-circuit detection phase difference range = 95.2 ° to 180 °, second overload / short-circuit detection phase difference range = −150 ° to −90 °
(2) Antiphase detection current change rate range = 0.9 to 1.1, antiphase detection voltage change rate range = 0.9 to 1.1, antiphase detection phase difference range = −60 ° to 0 °
(3) Phase loss / disconnection detection current change rate range = 0.4 to 0.6, first disconnection detection current change rate range = 0.2 to 0.4, second disconnection detection current change rate range = 0 .8 to 0.9, first open phase / disconnection detection voltage change rate range = 0.4 to 0.6, second open phase / disconnection detection voltage change rate range = 0.8 to 0.9, missing Phase detection voltage change rate value = 0.1, first open phase detection phase difference range = −30 ° to 30 °, second open phase detection phase difference range = 150 ° to 210 °, first disconnection detection position Phase difference range = 30 ° to 90 °, second disconnection detection phase difference range = 150 ° to 210 °, third disconnection detection phase difference range = 90 ° to 150 °, fourth disconnection detection phase difference range = 130 ° to 150 °, fifth disconnection detection phase difference range = 90 ° to 110 °

まず、過負荷または短絡事故発生時のリレー演算処理部５８の動作について、図２２に示すフローチャートを参照して説明する。
リレー演算処理部５８は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）以上であるか否かを調べ（ステップＳ６０）、電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値以上であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値（＝０．９６）以下であるか否かを調べる（ステップＳ６１）。
リレー演算処理部５８は、電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値以下でないと、「過負荷が発生した」と判定する（ステップＳ６９ａ）。 First, the operation of the relay calculation processing unit 58 when an overload or short circuit accident occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 58, the resultant current the current rate of change K _RS overload or short circuit detecting current change rate values I _RS (= 1.15) examines if the either more (step S60), the current change rate K _{If RS} is equal to or greater than the overload / short-circuit detection current change rate value, the voltage change rate L _TR of the TR phase line voltage V _TR is equal to or less than the first overload / short-circuit detection voltage change rate value (= 0.96). It is checked whether or not there is (step S61).
Relay processing section 58 determines, when the voltage change rate L _TR not less than the first overload or short circuit detecting voltage change rate value, the "overload has occurred" (step S69A).

ステップＳ６１において電圧変化率Ｌ_TRが第１の過負荷・短絡検出電圧変化率値以下であると、リレー演算処理部５８は、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べ（ステップＳ６２）、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下であると、Ｔ相電圧Ｖ_Tの位相変化角Δθ_Tが第３の過負荷・短絡検出位相変化角範囲（＝５．８°〜６０°）内の値であるか否かを調べる（ステップＳ６８）。
リレー演算処理部５８は、位相変化角Δθ_Tが第３の過負荷・短絡検出位相変化角範囲内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定し（ステップＳ６９ｄ）、一方、位相変化角Δθ_Tが第３の過負荷・短絡検出位相変化角範囲内の値でないと、「三相短絡が発生した」と判定する（ステップＳ６９ｅ）。 When the voltage change rate L _TR is equal to or less than the first overload / short circuit detection voltage change rate value in step S61, the relay calculation processing unit 58 determines that the voltage change rate L _TR is the second overload / short circuit detection voltage change rate. It is checked whether or not the value (= 0.8) or less (step S62). If the voltage change rate L _TR is less than or equal to the second overload / short-circuit detection voltage change rate value, the phase of the T-phase voltage V _T It is checked whether or not the change angle Δθ _T is a value within the third overload / short-circuit detection phase change angle range (= 5.8 ° to 60 °) (step S68).
When the phase change angle Δθ _T is a value within the third overload / short circuit detection phase change angle range, the relay calculation processing unit 58 determines that “TR phase short circuit has occurred” (step S69d). On the other hand, if the phase change angle Δθ _T is not a value within the third overload / short circuit detection phase change angle range, it is determined that “a three-phase short circuit has occurred” (step S69e).

一方、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下でないと、リレー演算処理部５８は、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲（＝５．２°〜３０°）内の値であるか否かを調べる（ステップＳ６３）。
リレー演算処理部５８は、位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲内の値であると、「Ｒ−Ｓ相短絡が発生した」と判定する（ステップＳ６９ｂ）。 On the other hand, when the voltage change rate L _TR not less than the second overload or short circuit detecting voltage change rate value, the relay processing unit 58, a phase change angle [Delta] [theta] _TR of the voltage V _TR - TR phase line first overload Whether or not the value is within the short-circuit detection phase change angle range (= 5.2 ° to 30 °) is checked (step S63).
When the phase change angle Δθ _TR is a value within the first overload / short-circuit detection phase change angle range, the relay calculation processing unit 58 determines that “RS phase short-circuit has occurred” (step S69b).

一方、位相変化角Δθ_TRが第１の過負荷・短絡検出位相変化角範囲内の値でないと、リレー演算処理部５８は、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲（＝−５．２°〜−３０°）内の値であるか否かを調べる（ステップＳ６６）。
リレー演算処理部５８は、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する（ステップＳ６９ｃ）。 On the other hand, if the phase change angle Δθ _TR is not a value within the first overload / short circuit detection phase change angle range, the relay calculation processing unit 58 determines that the phase change angle Δθ _TR is the second overload / short circuit detection phase change angle. It is checked whether or not the value is within a range (= −5.2 ° to −30 °) (step S66).
When the phase change angle Δθ _TR is a value within the second overload / short circuit detection phase change angle range, the relay calculation processing unit 58 determines that “ST phase short-circuit has occurred” (step S69c).

ステップＳ６０において電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）未満であると、リレー演算処理部５８は、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_Tが第３の過負荷・短絡検出電圧変化率値（＝０．８６）以下であるか否かを調べ（ステップＳ６４）、電圧変化率Ｌ_Tが第３の過負荷・短絡検出電圧変化率値以下であると、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べ（ステップＳ６５）、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下でないと、ＴＲ相線間電圧Ｖ_TRの位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲（＝−５．２°〜−３０°）内の値であるか否かを調べる（ステップＳ６６）。
リレー演算処理部５８は、位相変化角Δθ_TRが第２の過負荷・短絡検出位相変化角範囲内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する（ステップＳ６９ｃ）。 If the current rate of change K _RS is less than the overload or short circuit detected current change rate value (= 1.15) in step S60, the relay processing unit 58, the voltage change rate L _T of the T-phase voltage V _T is the third overload or short circuit detecting voltage change rate value (= 0.86) examined in whether or less (step S64), the voltage change rate L _T is below the third overload or short circuit detecting voltage change rate values When the voltage change rate L _TR second overload or short circuit detecting voltage change rate value (= 0.8) examines if the either less (step S65), the voltage change rate L _TR second overload - a short-circuit detecting not less voltage change rate value, the phase change angle [Delta] [theta] _TR of the voltage V _TR - TR phase line and the second overload or short circuit detecting the phase change angle range (= -5.2 ° ~-30 ° ) in It is checked whether or not the value is (step S66).
When the phase change angle Δθ _TR is a value within the second overload / short circuit detection phase change angle range, the relay calculation processing unit 58 determines that “ST phase short-circuit has occurred” (step S69c).

ステップＳ６５において電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下であると、リレー演算処理部５８は、Ｔ相電圧Ｖ_Tの位相変化角Δθ_Tが第３の過負荷・短絡検出位相変化角範囲（＝５．８°〜６０°）内の値であるか否かを調べる（ステップＳ６７）。
リレー演算処理部５８は、位相変化角Δθ_Tが第３の過負荷・短絡検出位相変化角範囲内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する（ステップＳ６９ｄ）。 When the voltage change rate L _TR is below the second overload or short circuit detecting voltage change rate value at step S65, the relay processing unit 58, a phase change angle [Delta] [theta] _T T-phase voltage V _T is the third overload Whether or not the value is within the short-circuit detection phase change angle range (= 5.8 ° to 60 °) is checked (step S67).
When the phase change angle Δθ _T is a value within the third overload / short circuit detection phase change angle range, the relay calculation processing unit 58 determines that “TR phase short circuit has occurred” (step S69d).

リレー演算処理部５８は、以上のようにして過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡または三相短絡の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ７０）。 When the relay calculation processing unit 58 detects the occurrence of overload, R-S phase short circuit, S-T phase short circuit, TR phase short circuit, or three-phase short circuit as described above, the first to third trip signals are detected. T _{1 to} T ₃ are output (step S70).

次に、反相発生時のリレー演算処理部５８の動作について、図２３に示すフローチャートを参照して説明する。
リレー演算処理部５８は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが反相検出電流変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ７１）、電流変化率Ｋ_R-Sが反相検出電流変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが反相検出電圧変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ７２）、電圧変化率Ｌ_TRが反相検出電圧変化率範囲内の値であると、Ｔ相電圧Ｖ_Rの電圧変化率Ｌ_Tが反相検出電圧変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ７３）、電圧変化率Ｌ_Tが反相検出電圧変化率範囲内の値であると、Ｔ相電圧Ｖ_Rの位相差βが反相検出位相差範囲（＝−６０°〜０°）内の値であるか否かを調べる（ステップＳ７４）。
リレー演算処理部５８は、位相差βが反相検出位相差範囲内の値であると、「反相が発生した」と判定して（ステップＳ７５）、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ７６）。 Next, the operation of the relay calculation processing unit 58 when a reverse phase occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 58 checks whether the combined current I current change rate K _RS of _RS is a value within the anti-phase detected current change rate range (= 0.9 to 1.1) (step S71), If the current rate of change K _RS is within the anti-phase detected current change rate range, the voltage change rate L _TR of the voltage V _TR - TR phase line reverse phase detecting voltage change rate range (= 0.9 to 1.1 ) examines if the value is either in (step S72), when the voltage change rate L _TR is within this reverse phase detecting voltage change rate range, the voltage change rate L _T of the T-phase voltage V _R is reverse phase detected voltage change rate ranges (= 0.9-1.1) examines whether the value of the (step S73), when the voltage change rate L _T is a value within the counter-phase detection voltage change rate range, It is checked whether or not the phase difference β of the T-phase voltage V _R is a value within the anti-phase detection phase difference range (= −60 ° to 0 °) (step S74).
When the phase difference β is a value within the anti-phase detection phase difference range, the relay calculation processing unit 58 determines that “an anti-phase has occurred” (step S75), and the first to third trip signals T _1. and it outputs the through T ₃ (step S76).

次に、スター結線された三相電源線における欠相または断線発生時のリレー演算処理部５８の動作について、図２４および図２５に示すフローチャートを参照して説明する。
リレー演算処理部５８は、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが第１の欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ８１）、電圧変化率Ｌ_TRが第１の欠相・断線検出電圧変化率範囲内の値であると、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ８２）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-Sの位相差αが第１の欠相検出位相差範囲（＝−３０°〜３０°）内の値であるか否かを調べる（ステップＳ８３）。
リレー演算処理部５８は、位相差αが第１の欠相検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ９２ａ）。 Next, the operation of the relay calculation processing unit 58 when a phase loss or disconnection occurs in a star-connected three-phase power supply line will be described with reference to the flowcharts shown in FIGS.
The relay calculation processing unit 58 determines whether or not the voltage change rate L _TR of the TR phase line voltage V _TR is a value within the first open phase / disconnection detection voltage change rate range (= 0.4 to 0.6). or the checked (step S81), when the voltage change rate L _TR is the value of the first phase loss-disconnection detecting voltage change rate range, the resultant current I _RS of the current rate of change K _RS is open phase-disconnection detection current change rate range (= 0.4-0.6) examines whether the value of the (step S82), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, It is checked whether or not the phase difference α of the combined current I _RS is a value within the first open phase detection phase difference range (= −30 ° to 30 °) (step S83).
When the phase difference α is a value within the first phase loss detection phase difference range, the relay calculation processing unit 58 determines that “R phase phase loss has occurred” (step S92a).

ステップＳ８１において電圧変化率Ｌ_TRが第１の相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部５８は、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ８４）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_Tが第２の欠相・断線検出電圧変化率範囲（＝０．８〜０．９）内の値であるか否かを調べ（ステップＳ８５）、電圧変化率Ｌ_Tが第２の欠相・断線検出電圧変化率範囲内の値であると、位相差αが第２の欠相検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ８６）。
リレー演算処理部５８は、位相差αが第２の欠相検出位相差範囲内の値であると、「Ｓ相欠相が発生した」と判定する（ステップＳ９２ｄ）。 If the voltage change rate _LTR is not a value within the first phase / disconnection detection voltage change rate range in step S81, the relay calculation processing unit 58 determines that the current change rate _KRS is an open phase / disconnection detection current change rate range (= examines whether the value of 0.4 to 0.6) in (step S84), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, T-phase voltage V _T voltage change rate L _T as it is checked whether the value of the second phase loss-disconnection detecting voltage change rate ranges (= 0.8-0.9) in (step S85), the voltage change rate L _T Whether the phase difference α is a value within the second open phase detection phase difference range (= 150 ° to 210 °) is checked if the value is within the second open phase / disconnection detection voltage change rate range. (Step S86).
When the phase difference α is a value within the second phase loss detection phase difference range, the relay calculation processing unit 58 determines that “S phase phase loss has occurred” (step S92d).

ステップＳ８２において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部５８は、電圧変化率Ｌ_Tが欠相検出電圧変化率値（＝０．１）以下であるか否かを調べ（ステップＳ８７）、電圧変化率Ｌ_Tが欠相検出電圧変化率値以下であると、位相差αが第２の欠相検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ８８）。
リレー演算処理部５８は、位相差αが第２の欠相検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ９２ｃ）。 If the current rate of change K _RS is not the value of the open phase-disconnection detecting the current change rate in the range at step S82, the relay processing unit 58, the voltage change rate L _T phase loss detection voltage change rate value (= 0.1) examines if less either (step S87), when the voltage change rate L _T is less phase loss detection voltage change rate value, the phase difference α is a second open-phase phase difference detection range (= 0.99 ° to 210 It is checked whether the value is within (°) (step S88).
When the phase difference α is a value within the second phase loss detection phase difference range, the relay calculation processing unit 58 determines that “T phase phase loss has occurred” (step S92c).

ステップＳ８５において電圧変化率Ｌ_Tが第２の欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部５８は、位相差αが第１の断線検出位相差範囲（＝３０°〜９０°）内の値であるか否かを調べる（図２５のステップＳ８９）。
リレー演算処理部５８は、位相差αが第１の断線検出位相差範囲内の値であると、「Ｒ相断線が発生した」と判定する（ステップＳ９２ｄ）。 When the voltage change rate L _T is not the second value of the open phase-disconnection detecting voltage change rate in the range at step S85, the relay processing unit 58, the phase difference α is a first disconnection detecting the phase difference range (= 30 ° It is checked whether the value is within the range of (˜90 °) (step S89 in FIG. 25).
When the phase difference α is a value within the first disconnection detection phase difference range, the relay calculation processing unit 58 determines that “R phase disconnection has occurred” (step S92d).

ステップＳ８９において位相差αが第１の断線検出位相差範囲内の値でないと、リレー演算処理部５８は、位相差αが第２の断線検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ９０）。
リレー演算処理部５８は、位相差αが第２の断線検出位相差範囲内の値であると、「Ｓ相断線が発生した」と判定する（ステップＳ９２ｅ）。 If the phase difference α is not a value within the first disconnection detection phase difference range in step S89, the relay calculation processing unit 58 determines that the phase difference α is within the second disconnection detection phase difference range (= 150 ° to 210 °). It is checked whether it is a value (step S90).
When the phase difference α is a value within the second disconnection detection phase difference range, the relay calculation processing unit 58 determines that “S phase disconnection has occurred” (step S92e).

ステップＳ８４において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部５８は、位相差αが第３の断線検出位相差範囲（＝９０°〜１５０°）内の値であるか否かを調べる（ステップＳ９１）。
リレー演算処理部５８は、位相差αが第３の断線検出位相差範囲内の値であると、「Ｔ相断線が発生した」と判定する（ステップＳ９２ｆ）。 If the current change rate _KRS is not a value within the phase loss / disconnection detection current change rate range in step S84, the relay calculation processing unit 58 determines that the phase difference α is equal to the third disconnection detection phase difference range (= 90 ° to 150 °). ) Is checked (step S91).
When the phase difference α is a value within the third disconnection detection phase difference range, the relay calculation processing unit 58 determines that “T-phase disconnection has occurred” (step S92f).

リレー演算処理部５８は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線またはＴ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ９３）。 When the relay arithmetic processing unit 58 detects the occurrence of the R-phase, S-phase, T-phase, R-phase, S-phase, or T-phase disconnection as described above, the first to third Trip signals T _{1 to} T ₃ are output (step S93).

次に、デルタ結線された三相電源線における欠相または断線発生時のリレー演算処理部５８の動作について、図２６および図２７に示すフローチャートを参照して説明する。
リレー演算処理部５８は、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが第１の欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１０１）、電圧変化率Ｌ_TRが第１の欠相・断線検出電圧変化率範囲内の値であると、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１０２）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-Sの位相差αが第１の欠相検出位相差範囲（＝−３０°〜３０°）内の値であるか否かを調べる（ステップＳ１０３）。
リレー演算処理部５８は、位相差αが第１の欠相検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ１１３ａ）。 Next, the operation of the relay calculation processing unit 58 when a phase loss or disconnection occurs in a delta-connected three-phase power supply line will be described with reference to the flowcharts shown in FIGS.
The relay calculation processing unit 58 determines whether or not the voltage change rate L _TR of the TR phase line voltage V _TR is a value within the first open phase / disconnection detection voltage change rate range (= 0.4 to 0.6). or the checked (step S101), when the voltage change rate L _TR is the value of the first phase loss-disconnection detecting voltage change rate range, the resultant current I _RS of the current rate of change K _RS is open phase-disconnection detection current change rate range (= 0.4-0.6) examines whether the value of the (step S102), the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, It is checked whether or not the phase difference α of the combined current I _RS is a value within the first open phase detection phase difference range (= −30 ° to 30 °) (step S103).
When the phase difference α is a value within the first phase loss detection phase difference range, the relay calculation processing unit 58 determines that “R phase phase loss has occurred” (step S113a).

ステップＳ１０１において電圧変化率Ｌ_TRが第１の欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部５８は、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１０４）、電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値であると、Ｔ相電圧Ｖ_Tの電圧変化率Ｌ_Tが第２の欠相・断線検出電圧変化率範囲（＝０．８〜０．９）内の値であるか否かを調べ（ステップＳ１０５）、電圧変化率Ｌ_Tが第２の欠相・断線検出電圧変化率範囲内の値であると、位相差αが第２の欠相検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ１０６）。
リレー演算処理部５８は、位相差αが第２の欠相検出位相差範囲内の値であると、「Ｓ相欠相が発生した」と判定する（ステップＳ１１３ｂ）。 If the voltage change rate _LTR is not a value within the first open phase / disconnection detection voltage change rate range in step S101, the relay calculation processing unit 58 determines that the current change rate _KRS is the open phase / disconnection detection current change rate range ( = 0.4 to 0.6) examines if the value is either inside (step S104), and the current rate of change K _RS is a value open phase-disconnection detecting the current change rate in the range, T-phase voltage V voltage change rate L _T of the _T are checked whether the value of the second phase loss-disconnection detecting voltage change rate ranges (= 0.8-0.9) in (step S105), the voltage change rate L _T Is a value within the second open phase / disconnection detection voltage change rate range, whether or not the phase difference α is a value within the second open phase detection phase difference range (= 150 ° to 210 °). It investigates (step S106).
When the phase difference α is a value within the second phase loss detection phase difference range, the relay calculation processing unit 58 determines that “S phase phase loss has occurred” (step S113b).

ステップＳ１０２において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部５８は、電圧変化率Ｌ_Tが欠相検出電圧変化率値（＝０．１）以下であるか否かを調べ（ステップＳ１０７）、電圧変化率Ｌ_Tが欠相検出電圧変化率値（＝０．１）以下であると、位相差αが第２の欠相検出位相差範囲（＝１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ１０８）。
リレー演算処理部５８は、位相差αが第２の欠相検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ１１３ｃ）。 If the current rate of change K _RS is not the value of the open phase-disconnection detecting the current change rate in the range in step S102, the relay processing unit 58, the voltage change rate L _T phase loss detection voltage change rate value (= 0.1) examines if the either less (step S107), when the voltage change rate L _T is phase loss detection voltage change rate value (= 0.1) or less, the phase difference α is a second open-phase phase difference detection range It is checked whether the value is within the range (= 150 ° to 210 °) (step S108).
When the phase difference α is a value within the second phase loss detection phase difference range, the relay calculation processing unit 58 determines that “T phase phase loss has occurred” (step S113c).

ステップＳ１０４において電流変化率Ｋ_R-Sが欠相・断線検出電流変化率範囲内の値でないと、リレー演算処理部５８は、電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲（＝０．２〜０．４）内の値であるか否かを調べる（図２７のステップＳ１０９）。
リレー演算処理部５８は、電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲内の値であると、「Ｒ相断線が発生した」と判定する（ステップＳ１１３ｄ）。 If the current change rate K _RS is not a value within the phase loss / disconnection detection current change rate range in step S104, the relay calculation processing unit 58 determines that the current change rate K _RS is within the first disconnection detection current change rate range (= 0. 2 to 0.4) is checked (step S109 in FIG. 27).
Relay processing section 58, the current rate of change K _RS is the value of the first disconnection detecting the current change rate range, it is determined that the "R-phase disconnection has occurred" (step S113d).

一方、ステップＳ１０９において電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲内の値でないと、リレー演算処理部５８は、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲（＝０．８〜０．９）内の値であるか否かを調べ（ステップＳ１１０）、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲内の値であると、位相差αが第４の断線検出位相差範囲（＝１３０°〜１５０°）内の値であるか否かを調べる（ステップＳ１１１）。
リレー演算処理部５８は、位相差αが第４の断線検出位相差範囲内の値であると、ＳＴ相断線が発生した」と判定する（ステップＳ１１３ｅ）。 On the other hand, if the current change rate K _RS is not a value within the first disconnection detection current change rate range in step S109, the relay calculation processing unit 58 determines that the current change rate K _RS is equal to the second disconnection detection current change rate range (= It examines whether the value of 0.8-0.9) in (step S110), if the current rate of change K _RS is the value of the second disconnection detecting the current change rate range, the phase difference α is a It is checked whether or not the value is within the disconnection detection phase difference range of 4 (= 130 ° to 150 °) (step S111).
The relay calculation processing unit 58 determines that the ST phase disconnection has occurred when the phase difference α is a value within the fourth disconnection detection phase difference range (step S113e).

一方、ステップＳ１１１において位相差αが第４の断線検出位相差範囲内の値でないと、リレー演算処理部５８は、位相差αが第５の断線検出位相差範囲（＝９０°〜１１０°）内の値であるか否かを調べる（ステップＳ１１２）。
リレー演算処理部５８は、位相差αが第５の断線検出位相差範囲内の値であると、「ＴＲ相断線が発生した」と判定する（ステップＳ１１３ｆ）。 On the other hand, if the phase difference α is not a value within the fourth disconnection detection phase difference range in step S111, the relay calculation processing unit 58 determines that the phase difference α is the fifth disconnection detection phase difference range (= 90 ° to 110 °). It is checked whether the value is within the range (step S112).
When the phase difference α is a value within the fifth disconnection detection phase difference range, the relay calculation processing unit 58 determines that “TR phase disconnection has occurred” (step S113f).

リレー演算処理部５８は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線またはＴＲ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ１１４）。 When the relay calculation processing unit 58 detects the occurrence of the R-phase open phase, the S-phase open phase, the T-phase open phase, the RS phase open wire, the ST phase open wire, or the TR phase open wire as described above, Trip signals T _{1 to} T ₃ are output (step S114).

次に、本発明の第３の実施例による保護継電システムについて、図２８乃至図４０を参照して説明する。
本実施例による保護継電システムは、図２８に示すように、三相電源線のＲ相およびＳ相がクロスするように貫通されたクロス貫通変流器６１と、三相電源線に設けられた計器用変成器６２と、クロス貫通変流器６１から入力される合成電流Ｉ_R-Sと計器用変成器６２から入力されるＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRとに基づいて三相電源線における過負荷、短絡、反相、欠相および断線を検出する三相誘導電動機用３Ｅリレー７０（以下、「３Ｅリレー７０」と称する。）とを具備する。 Next, a protection relay system according to a third embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 28, the protection relay system according to the present embodiment is provided in the three-phase power supply line and the cross-through current transformer 61 that is penetrated so that the R phase and the S phase of the three-phase power supply line cross each other. Instrument transformer 62, combined current I _RS input from cross-through current transformer 61, RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase input from instrument transformer 62 A 3E relay 70 for a three-phase induction motor (hereinafter referred to as “3E relay 70”) that detects overload, short circuit, reverse phase, phase loss, and disconnection in a three-phase power supply line based on the line voltage V _TR . It comprises.

ここで、クロス貫通変流器６１は、図１に示したクロス貫通変流器１１および図１７に示したクロス貫通変流器４１と同じものである。
計器用変成器６２は、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRを３Ｅリレー７０に出力する。 Here, the cross through current transformer 61 is the same as the cross through current transformer 11 shown in FIG. 1 and the cross through current transformer 41 shown in FIG.
Instrument transformer 62 outputs RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR to 3E relay 70.

３Ｅリレー７０は、クロス貫通変流器６１から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-S、ＳＴ基準位相差α_ST（ＳＴ相線間電圧Ｖ_STの位相θ_STに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）およびＴＲ基準位相差α_TR（ＴＲ相線間電圧Ｖ_TRの位相θ_TRに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）と計器用変成器６２から入力されるＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRとに基づいて、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡を検出する。
また、３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-SとＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RS（ＴＲ相線間電圧Ｖ_TRの位相θ_TRに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）とに基づいて、Ｒ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相を検出する。
さらに、３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-SおよびＴＲ基準位相差α_TRとＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_ST（ＲＳ相線間電圧Ｖ_RSの位相θ_RSに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）とＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TR（ＳＴ相線間電圧Ｖ_STの位相θ_STに対する位相差であり、遅れ位相を正の値で進み位相を負の値で示す。以下同様）とに基づいて、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線を検出するとともに、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出する。
３Ｅリレー７０は、以上のようにして過負荷などを検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The 3E relay 70 is a current change rate K _RS of the combined current I _RS input from the cross-through current transformer 61, an ST reference phase difference α _ST (a phase difference with respect to the phase θ _ST of the ST phase line voltage V _ST , The lag phase is a positive value and the lead phase is a negative value (the same applies hereinafter) and the TR reference phase difference α _TR (the phase difference with respect to the phase θ _TR of the TR phase line voltage V _TR and the lag phase is a positive value) And the phase change is indicated by a negative value (the same applies hereinafter) and the voltage change rate of the RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR input from the instrument transformer 62. Based on L _RS , L _ST , and L _TR , an overload, an RS phase short circuit, an _ST phase short circuit, a _TR phase short circuit, and a three phase short circuit are detected.
Further, 3E relay 70, the composite current I _RS of the current change rate K _RS and RS-phase line voltage V _RS, the voltage change rate L _RS voltage V _ST and TR phase line voltage V _TR between ST phase line, L _ST is the phase difference for the phase theta _TR of L _TR between the RS phase line voltage V _RS of the TR reference phase difference beta _RS (TR phase line voltage V _TR, the phase lead lag phase at a positive value at a negative value Based on the following, the R—S reciprocal phase, the S—T reciprocal phase, and the T—R reciprocal phase are detected.
Furthermore, 3E relay 70, the composite current I _RS of the current rate of change K _RS and TR reference phase difference alpha _TR and RS phase line voltage V _RS, ST-phase line voltage V _ST and TR phase line voltage of the voltage V _TR Rate of change L _RS , L _ST , L _TR and RS phase line voltage V _RS TR reference phase difference β _RS and ST phase line voltage V _ST RS reference phase difference β _ST (RS phase line voltage V _RS phase θ is the phase difference with respect to _RS, indicating the phase advance and phase delay in a positive value at a negative value. hereinafter the same) and ST reference phase difference beta _TR of TR-phase line voltage V _TR (ST phase line voltage V _ST Phase difference with respect to the phase _θST of the phase, and the lagging phase is a positive value, the leading phase is indicated by a negative value, and so on. R phase in three-phase power supply line that detects open phase, T phase open phase, R phase open wire, S phase open wire and T phase open wire Phase, S Aiketsusho, T Aiketsusho, RS phase disconnection, to detect the ST phase disconnection and TR phase disconnection.
When the 3E relay 70 detects an overload or the like as described above, the 3E relay 70 outputs the first to third trip signals T _{1 to} T ₃ to the first to third circuit breakers 3 _{1 to} 3 ₃ , respectively.

次に、３Ｅリレー７０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について、図２９乃至図３１を参照して詳しく説明する。   Next, a method for detecting overload, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit in the 3E relay 70 will be described in detail with reference to FIGS. 29 to 31.

（１）正常時の合成電流Ｉ_(R-S)0、ＲＳ相線間電圧Ｖ_RS0、ＳＴ相線間電圧Ｖ_ST0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＲＳ相線間電圧Ｖ_RS0の値｜Ｖ_RS0｜および位相θ_RS0と正常時のＳＴ相線間電圧Ｖ_ST0の値｜Ｖ_ST0｜および位相θ_ST0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは（４１−１）式から（４１−８）式でそれぞれ表される（図２９（ａ），（ｂ）参照）。
｜Ｉ_(R-S)0｜＝｜Ｉ_R0−Ｉ_S0｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１＝３^1/2 （４１−１）
θ_(R-S)0＝３３０° （４１−２）
｜Ｖ_RS0｜＝｜Ｖ_R0−Ｖ_S0｜＝３^1/2×｜Ｖ_R0｜＝３^1/2×１＝３^1/2 （４１−３）
θ_RS0＝３３０° （４１−４）
｜Ｖ_ST0｜＝｜Ｖ_S0−Ｖ_T0｜＝３^1/2×｜Ｖ_S0｜＝３^1/2×１＝３^1/2 （４１−５）
θ_ST0＝９０° （４１−６）
｜Ｖ_TR0｜＝｜Ｖ_T0−Ｖ_R0｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１＝３^1/2 （４１−７）
θ_TR0＝２１０° （４１−８） (1) Composite current I _{(RS) 0} at normal time, RS phase line voltage V _RS0 , ST phase line voltage V _ST0 and TR phase line voltage V _TR0
Normal value of combined current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal RS phase line voltage V _RS0 | V _RS0 | and phase θ _RS0 and normal The value | V _ST0 | and the phase θ _ST0 of the ST phase line voltage V _{ST0 and} the value of the TR phase line voltage V _{TR0 in} the normal state | V _TR0 | and the phase θ _TR0 from the equation (41-1) (41 −8) respectively represented by the equations (see FIGS. 29A and 29B).
| I _{(RS) 0} | = | I _R0 −I _S0 | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1 = 3 ^1/2 (41-1)
θ _{(RS) 0} = 330 ° (41-2)
| V _RS0 | = | V _R0 −V _S0 | = 3 ^1/2 × | V _R0 | = 3 ^1/2 × 1 = 3 ^1/2 (41-3)
θ _RS0 = 330 ° (41-4)
| V _ST0 | = | V _S0 −V _T0 | = 3 ^1/2 × | V _S0 | = 3 ^1/2 × 1 = 3 ^1/2 (41-5)
θ _ST0 = 90 ° (41-6)
| V _TR0 | = | V _T0 −V _R0 | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1 = 3 ^1/2 (41-7)
θ _TR0 = 210 ° (41-8)

（２）過負荷時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
過負荷が発生して定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tが三相電源線のＲ相、Ｓ相およびＴ相にそれぞれ流れたとすると、過負荷時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４２−１）式から（４２−１４）式でそれぞれ表される（図３０（ａ），（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝＝３^1/2×（１．１５×｜Ｉ_R0｜）
＝３^1/2×（１．１５×１）＝３^1/2×１．１５ （４２−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2×１．１５）／３^1/2
＝１．１５ （４２−２）
θ_R-S＝３３０° （４２−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝３^1/2×｜Ｖ_R｜＝３^1/2×｜Ｖ_R0｜＝３^1/2×１
＝３^1/2 （４２−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝３^1/2／３^1/2＝１ （４２−５）
θ_RS＝３３０° （４２−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝３^1/2×｜Ｖ_S｜＝３^1/2×｜Ｖ_S0｜＝３^1/2×１
＝３^1/2 （４２−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝３^1/2／３^1/2＝１ （４２−８）
θ_ST＝９０° （４２−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （４２−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （４２−１１）
θ_TR＝２１０° （４２−１２）
α_ST＝θ_R-S−θ_ST＝３３０°−９０°＝２７０°＝−１２０° （４２−１３）
α_TR＝θ_R-S−θ_TR＝３３０°−２１０°＝１２０° （４２−１４） (2) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR during overload
R-phase, S-phase, and T-phase currents that are 1.15 times the rated current values (in this example, normal R-phase, S-phase, and T-phase currents I _R0 , I _S0 , I _T0 ) due to overload I _R, I _S, R-phase of the I _T is a three-phase power line, assuming that respectively flow into S phase and T-phase, the value of the composite current I _RS during overload | I _RS |, the current change rate K _RS and phase Value of θ _RS and RS phase line voltage V _RS | V _RS |, voltage change rate L _RS and phase θ _RS and value of ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST And TR phase line voltage V _TR | V _TR |, voltage change rate L _TR and phase θ _TR, and ST reference phase difference α _ST and TR reference phase difference α _{TR of} combined current I _RS (42-1) From the equations, they are expressed by equations (42-14) (see FIGS. 30A and 30B).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | == 3 ^1/2 × (1.15 × | I _R0 |)
= 3 ^1/2 × (1.15 × 1) = 3 ^1/2 × 1.15 (42-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 × 1.15) / 3 ^1/2
= 1.15 (42-2)
θ _RS = 330 ° (42-3)
| V _RS | = | V _R −V _S | = 3 ^1/2 × | V _R | = 3 ^1/2 × | V _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (42-4)
_{L RS = | V RS | /} | V RS0 | = 3 1/2 / 3 1/2 = 1 (42-5)
θ _RS = 330 ° (42-6)
| V _ST | = | V _S −V _T | = 3 ^1/2 × | V _S | = 3 ^1/2 × | V _S0 | = 3 ^1/2 × 1
= 3 ^1/2 (42-7)
L _ST = | V _ST | / | V _ST0 | = 3 ^1/2 / 3 ^1/2 = 1 (42-8)
θ _ST = 90 ° (42-9)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (42-10)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (42-11)
θ _TR = 210 ° (42-12)
α _ST = θ _RS −θ _ST = 330 ° −90 ° = 270 ° = −120 ° (42-13)
α _TR = θ _RS −θ _TR = 330 ° -210 ° = 120 ° (42-14)

（３）Ｒ−Ｓ相短絡時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
Ｒ相−Ｓ相間の短絡事故（Ｒ−Ｓ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＲ相およびＳ相事故電流Ｉ_FR，Ｉ_FSが流れたとすると、Ｒ−Ｓ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４３−１）式から（４３−１４）式でそれぞれ表される（図４（ａ−１），図３０（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_FS｜＝２×｜Ｉ_FR｜＝２×（１．１５×｜Ｉ_R0｜）
＝２×（１．１５×１）＝２×１．１５＝２．３ （４３−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝２．３／３^1/2（＝１．３２８） （４３−２）
θ_R-S＝４５° （４３−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝０．８×３^1/2 （４３−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４３−５）
θ_RS＝３３０° （４３−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４３−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４３−８）
θ_ST＝８４．８° （４３−９）
｜Ｖ_TR｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４３−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４３−１１）
θ_TR＝２１５．２° （４３−１２）
α_ST＝θ_R-S−θ_ST＝４５°−８４．８°＝−３９．８° （４３−１３）
α_TR＝θ_R-S−θ_TR＝４５°−２１５．２°＝−１７０．２° （４３−１４） (3) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when _RS phase is short-circuited
An R phase that is 1.15 times the rated current value (in this example, the normal R phase and S phase currents I _R0 , I _S0 ) due to a short circuit accident between the R phase and the S phase (R-S phase short circuit) And S phase fault currents I _FR and I _FS flow, the value | I _RS | of the combined current I _RS when the _RS phase is short-circuited, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS Value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR and the ST reference phase difference α _ST and the TR reference phase difference α _{TR of the} combined current I _RS are expressed by the equations (43-1) to (43-14), respectively. (Refer to FIG. 4A-1 and FIG. 30B).
| I _RS | = | I _FR −I _FS | = 2 × | I _FR | = 2 × (1.15 × | I _R0 |)
= 2 × (1.15 × 1) = 2 × 1.15 = 2.3 (43-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 2.3 / 3 ^1/2 (= 1.328) (43-2)
θ _RS = 45 ° (43-3)
| V _RS | = | V _R −V _S | = 0.8 × 3 ^1/2 (43-4)
L _RS = | V _RS | / | V _RS0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (43-5)
θ _RS = 330 ° (43-6)
| V _ST | = | V _S −V _T | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (43-7)
L _ST = | V _ST | / | V _ST0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (43-8)
θ _ST = 84.8 ° (43-9)
| V _TR | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (43-10)
L _TR = | V _TR | / | V _TR0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (43-11)
θ _TR = 215.2 ° (43-12)
α _ST = θ _RS −θ _ST = 45 ° −84.8 ° = −39.8 ° (43-13)
α _TR = θ _RS −θ _TR = 45 ° -215.2 ° = −170.2 ° (43-14)

（４）Ｓ−Ｔ相短絡時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
Ｓ相−Ｔ相間の短絡事故（Ｓ−Ｔ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４４−１）式から（４４−１４）式でそれぞれ表される（図４（ｂ−１），図３１（ａ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R0−Ｉ_FS｜＝｜Ｉ_R0−１．１５Ｉ_S0｜
＝（｜Ｉ_R0｜²＋｜１．１５Ｉ_S0｜²−２×｜Ｉ_R0｜×｜１．１５Ｉ_S0｜×ｃｏｓ１６５°）^1/2
＝（１²＋１．１５²−２×１×１．１５×ｃｏｓ１６５°）^1/2
＝２．１３２ （４４−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝２．１３２／３^1/2＝１．２３１ （４４−２）
θ_R-S＝３５３° （４４−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４４−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４４−５）
θ_RS＝３３５．２° （４４−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝０．８×３^1/2 （４４−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４４−８）
θ_ST＝９０° （４４−９）
｜Ｖ_TR｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４４−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４４−１１）
θ_TR＝２０４．８° （４４−１２）
α_ST＝θ_R-S−θ_ST＝３５３°−９０°＝２６３°＝−９７° （４４−１３）
α_TR＝θ_R-S−θ_TR＝３５３°−２０４．８°＝１４８．２° （４４−１４）
また、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたとすると、Ｓ−Ｔ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４４−１５）式から（４４−１９）式でそれぞれ表される（図４（ｂ）の一点鎖線参照）。
｜Ｉ_R-S｜＝｜−Ｉ_FS｜≫｜１．１５Ｉ_S0｜≫１．１５ （４４−１５）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜≫１．１５／３^1/2（＝０．６６４） （４４−１６）
θ_R-S＝３４５° （４４−１７）
α_ST＝θ_R-S−θ_ST＝３４５°−９０°＝２５５°＝−１０５° （４４−１８）
α_TR＝θ_R-S−θ_TR＝３４５°−２０４．８°＝１４０．２° （４４−１９） (4) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR when the S-T phase is short-circuited
An S phase that is 1.15 times the rated current value (in this example, the normal R phase and S phase currents I _R0 , I _S0 ) due to a short circuit accident between the S phase and the T phase (S-T phase short circuit) And T-phase fault currents I _FS and I _FT flow, the value | I _RS | of the combined current I _RS when the ST phase is short-circuited, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS Value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR | V _TR |, the ST reference phase difference alpha _ST and TR reference phase difference alpha _TR of the voltage change rate L _TR and the phase theta _TR with combined current I _RS (44-1), respectively from the (44-14) by the formula formula (Refer to FIG. 4B-1 and FIG. 31A).
| I _RS | = | I _R0 −I _FS | = | I _R0 −1.15I _S0 |
= (| I _R0 | ² + | 1.15I _S0 | ² −2 × | I _R0 | × | 1.15I _S0 | × cos 165 °) ^1/2
= (1 ² +1.15 ² -2 × 1 × 1.15 × cos 165 °) ^1/2
= 2.132 (44-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 2.132 / 3 ^1/2 = 1.231 (44-2)
θ _RS = 353 ° (44-3)
| V _RS | = | V _R −V _S | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (44-4)
L _RS = | V _RS | / | V _RS0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (44-5)
θ _RS = 335.2 ° (44-6)
| V _ST | = | V _S −V _T | = 0.8 × 3 ^1/2 (44-7)
L _ST = | V _ST | / | V _ST0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (44-8)
θ _ST = 90 ° (44-9)
| V _TR | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (44-10)
L _TR = | V _TR | / | V _TR0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (44-11)
θ _TR = 204.8 ° (44-12)
α _ST = θ _RS −θ _ST = 353 ° −90 ° = 263 ° = −97 ° (44-13)
α _TR = θ _RS −θ _TR = 353 ° -204.8 ° = 148.2 ° (44-14)
Also, assuming that the S-phase and T-phase fault currents I _FS and I _{FT exceeding} the rated current value flow, the value of the combined current I _RS at the time of the S-T phase short circuit | I _RS |, the current change rate K _RS and The ST reference phase difference α _ST and the TR reference phase difference α _{TR of the} phase θ _RS and the combined current I _RS are expressed by the expressions (44-15) to (44-19), respectively (one point in FIG. 4B). (See chain line).
| I _RS | = | −I _FS | >> | 1.15I _S0 | >> 1.15 (44-15)
K _RS = | I _RS | / | I _{(RS) 0} | >> 1.15 / 3 ^1/2 (= 0.664) (44-16)
θ _RS = 345 ° (44-17)
α _ST = θ _RS −θ _ST = 345 ° −90 ° = 255 ° = −105 ° (44-18)
α _TR = θ _RS −θ _TR = 345 ° -204.8 ° = 140.2 ° (44-19)

（５）Ｔ−Ｒ相短絡時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
Ｔ相−Ｒ相間の短絡事故（Ｔ−Ｒ相短絡）が発生して定格電流値（この例では、正常時のＲ相およびＳ相電流Ｉ_R0，Ｉ_S0）の１．１５倍のＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４５−１）式から（４５−１４）式でそれぞれ表される（図５（ａ−１），図３１（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_S0｜＝｜１．１５Ｉ_R0−Ｉ_S0｜
＝（｜１．１５Ｉ_R0｜²＋｜Ｉ_S0｜²−２×｜１．１５Ｉ_R0｜×｜Ｉ_S0｜×ｃｏｓ１５°）^1/2
＝（１．１５²＋１²−２×１．１５×１×ｃｏｓ１５°）^1/2
＝０．３１８ （４５−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝０．３１８／３^1/2＝０．１８３ （４５−２）
θ_R-S＝５０．４° （４５−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４５−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４５−５）
θ_RS＝３２４．８° （４５−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2 （４５−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝｛１．５²＋（０．８×３^1/2／２）²｝^1/2／３^1/2
（＝０．９５４） （４５−８）
θ_ST＝９５．２° （４５−９）
｜Ｖ_TR｜＝０．８×３^1/2 （４５−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４５−１１）
θ_TR＝２１０° （４５−１２）
α_ST＝θ_R-S−θ_ST＝５０．４°−９５．２°＝−４４．８° （４５−１３）
α_TR＝θ_R-S−θ_TR＝５０．４°−２１０°＝−１５９．６° （４５−１４）
また、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたとすると、Ｔ−Ｒ相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４５−１５）式から（４５−１９）式でそれぞれ表される（図４（ｃ）の一点鎖線参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR｜≫１．１５×｜Ｉ_R0｜≫１．１５ （４５−１５）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜≫１．１５／３^1/2（＝０．６６４） （４５−１６）
θ_R-S＝１０５° （４５−１７）
α_ST＝θ_R-S−θ_ST＝１０５°−９５．２＝９．８° （４５−１８）
α_TR＝θ_R-S−θ_TR＝１０５°−２１０°＝−１０５° （４５−１９） (5) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR when T-R phase is short-circuited
T phase that is 1.15 times the rated current value (in this example, normal R phase and S phase currents I _R0 , I _S0 ) due to a short circuit accident between T phase and R phase (TR phase short circuit) And R-phase fault currents I _FT and I _FR flow, the value of the combined current I _RS when the TR phase is short-circuited | I _RS |, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS Value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR and the ST reference phase difference α _ST and the TR reference phase difference α _{TR of the} combined current I _RS are expressed by the equations (45-1) to (45-14), respectively. (Refer to FIG. 5A-1 and FIG. 31B).
| I _RS | = | I _FR −I _S0 | = | 1.15 I _R0 −I _S0 |
= (| 1.15I _R0 | ² + | I _S0 | ² −2 × | 1.15I _R0 | × | I _S0 | × cos 15 °) ^1/2
= (1.15 ² +1 ² -2 × 1.15 × 1 × cos 15 °) ^1/2
= 0.318 (45-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 0.318 / 3 ^1/2 = 0.183 (45-2)
θ _RS = 50.4 ° (45-3)
| V _RS | = | V _R −V _S | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (45-4)
L _RS = | V _RS | / | V _RS0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (45-5)
θ _RS = 324.8 ° (45-6)
| V _ST | = | V _S −V _T | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 (45-7)
L _ST = | V _ST | / | V _ST0 | = {1.5 ² + (0.8 × 3 ^1/2 / 2) ² } ^1/2 / 3 ^1/2
(= 0.954) (45-8)
θ _ST = 95.2 ° (45-9)
| V _TR | = 0.8 × 3 ^1/2 (45-10)
L _TR = | V _TR | / | V _TR0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (45-11)
θ _TR = 210 ° (45-12)
α _ST = θ _RS −θ _ST = 50.4 ° −95.2 ° = −44.8 ° (45-13)
α _TR = θ _RS −θ _TR = 50.4 ° −210 ° = −159.6 ° (45-14)
Further, assuming that the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow, the value of the combined current I _RS at the time of the TR phase short circuit | I _RS |, the current change rate K _RS and The ST reference phase difference α _ST and the TR reference phase difference α _{TR of the} phase θ _RS and the combined current I _RS are respectively expressed by the expressions (45-15) to (45-19) (one point in FIG. 4C). (See chain line).
| I _RS | = | I _FR | >> 1.15 × | I _R0 | >> 1.15 (45-15)
K _RS = | I _RS | / | I _{(RS) 0} | >> 1.15 / 3 ^1/2 (= 0.664) (45-16)
θ _RS = 105 ° (45-17)
α _ST = θ _RS −θ _ST = 105 ° -95.2 = 9.8 ° (45-18)
α _TR = θ _RS −θ _TR = 105 ° −210 ° = −105 ° (45-19)

（６）三相短絡時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相短絡事故（三相短絡）が発生して定格電流値（この例では、正常時のＲ相、Ｓ相およびＴ相電流Ｉ_R0，Ｉ_S0，Ｉ_T0）の１．１５倍のＲ相、Ｓ相およびＴ相事故電流Ｉ_FR，Ｉ_FS，Ｉ_FTが流れたとすると、三相短絡時の合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRと合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TRとは（４６−１）式から（４６−１４）式でそれぞれ表される（図５（ｂ−１），図３１（ｃ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_FR−Ｉ_FS｜＝３^1/2×｜Ｉ_FR｜＝３^1/2×（｜１．１５Ｉ_R0｜）
＝３^1/2×（１．１５×１）＝３^1/2×１．１５
（＝１．９９２） （４６−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2×１．１５）／３^1/2
＝１．１５ （４６−２）
θ_R-S＝４５° （４６−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝０．８×３^1/2 （４６−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４６−５）
θ_RS＝３３０° （４６−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝０．８×３^1/2 （４６−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４６−８）
θ_ST＝９０° （４６−９）
｜Ｖ_TR｜＝０．８×３^1/2 （４６−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（０．８×３^1/2）／３^1/2＝０．８ （４６−１１）
θ_TR＝２１０° （４６−１２）
α_ST＝θ_R-S−θ_ST＝４５°−９０°＝−４５° （４６−１３）
α_TR＝θ_R-S−θ_TR＝４５°−２１０°＝−１６５° （４６−１４） (6) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR during three-phase short circuit
R phase that is 1.15 times the rated current value (in this example, normal R phase, S phase, and T phase currents I _R0 , I _S0 , I _T0 ) due to the occurrence of a three-phase short circuit accident (three-phase short circuit) , S-phase and T-phase fault currents I _FR , I _FS , I _FT flow, value of combined current I _RS at three-phase short circuit | I _RS |, current change rate K _RS and phase θ _RS and RS phase line The value of the voltage V _RS | V _RS |, the voltage change rate L _RS and the phase θ _RS and the ST phase line voltage V _ST | V _ST |, the voltage change rate L _ST and the phase θ _ST and the TR phase line voltage the value of V _TR | V _TR |, the ST reference phase difference alpha _ST and TR reference phase difference alpha _TR of the voltage change rate L _TR and the phase theta _TR resultant current I _RS from (46-1) below (46-14 ) (Refer to FIG. 5 (b-1) and FIG. 31 (c)).
| I _RS | = | I _FR −I _FS | = 3 ^1/2 × | I _FR | = 3 ^1/2 × (| 1.15I _R0 |)
= 3 ^1/2 × (1.15 × 1) = 3 ^1/2 × 1.15
(= 1.992) (46-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 × 1.15) / 3 ^1/2
= 1.15 (46-2)
θ _RS = 45 ° (46-3)
| V _RS | = | V _R −V _S | = 0.8 × 3 ^1/2 (46-4)
L _RS = | V _RS | / | V _RS0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (46-5)
θ _RS = 330 ° (46-6)
| V _ST | = | V _S −V _T | = 0.8 × 3 ^1/2 (46-7)
L _ST = | V _ST | / | V _ST0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (46−8)
θ _ST = 90 ° (46-9)
| V _TR | = 0.8 × 3 ^1/2 (46-10)
L _TR = | V _TR | / | V _TR0 | = (0.8 × 3 ^1/2 ) / 3 ^1/2 = 0.8 (46-11)
θ _TR = 210 ° (46-12)
α _ST = θ _RS −θ _ST = 45 ° −90 ° = −45 ° (46-13)
α _TR = θ _RS −θ _TR = 45 ° −210 ° = −165 ° (46-14)

（７）過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出
合成電流Ｉ_R-Sの位相θ_R-Sがアーク抵抗の影響により−４５°〜１５°の範囲で変動することを考慮する。
（ａ）過負荷の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が所定の過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）が所定の第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）よりも大きいと、「過負荷が発生した」と判定する。
（ｂ）Ｒ−Ｓ相短絡の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．３２８）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．８）が所定の第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．９５４）が第２の過負荷・短絡検出電圧変化率値よりも大きいと、「Ｒ−Ｓ相短絡が発生した」と判定する。
（ｃ）Ｓ−Ｔ相短絡の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１，２３１）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-SのＳＴ基準位相差α_ST（＝−９７°）が所定の第１の過負荷・短絡検出位相差範囲（たとえば、−１５０°〜−９０°）内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
また、３Ｅリレー７０は、定格電流値よりも過大なＳ相およびＴ相事故電流Ｉ_FS，Ｉ_FTが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であっても、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-SのＳＴ基準位相差α_ST（＝−１０５°）が第１の過負荷・短絡検出位相差範囲（たとえば、−１５０°〜−９０°）内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する。
（ｄ）Ｔ−Ｒ相短絡の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．１８３）が過負荷・短絡検出電流変化率値（たとえば、１．１５）未満であり、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．９５４）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝−１５９．６°）が所定の第２の過負荷・短絡検出位相差範囲（たとえば、−２０３．１°〜−９０°）内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する。
また、３Ｅリレー２０は、定格電流値よりも過大なＴ相およびＲ相事故電流Ｉ_FT，Ｉ_FRが流れたときのために、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（≫０．６６４）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であっても、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．９５４）が第１の過負荷・短絡検出電圧変化率値（たとえば、０．９６）以下で第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．９５４）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）よりも大きく、かつ、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝−１４０．２°）が第２の過負荷・短絡検出位相差範囲（たとえば、−２０３．１°〜−９０°）内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する。
（ｅ）三相短絡の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１．１５）が過負荷・短絡検出電流変化率値（たとえば、１．１５）以上であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．８）が第２の過負荷・短絡検出電圧変化率値（たとえば、０．８）以下であり、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．８）が第２の過負荷・短絡検出電圧変化率値以下であると、「三相短絡が発生した」と判定する。 (7) overload, RS-phase short circuit, S-T phase short-circuit, T-R phase short-circuit and three-phase short circuit detecting the resultant current I _RS phase theta _RS is -45 ° to 15 ° due to the influence of the arc resistance Consider fluctuations in range.
(A) Overload detection In the 3E relay 70, the current change rate K _RS (= 1.15) of the combined current I _RS is equal to or greater than a predetermined overload / short-circuit detection current change rate value (eg, 1.15). When the voltage change rate L _RS (= 1) of the RS phase line voltage V _RS is larger than a predetermined first overload / short-circuit detection voltage change rate value (for example, 0.96), Is determined to occur.
(B) Detection of R-S phase short circuit The 3E relay 70 has a current change rate K _RS (= 1.328) of the combined current I _RS that is equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15). And the voltage change rate L _RS (= 0.8) of the RS phase line voltage V _RS is equal to or less than a predetermined second overload / short-circuit detection voltage change rate value (for example, 0.8), and When the voltage change rate L _ST (= 0.954) of the ST phase line voltage V _ST is larger than the second overload / short circuit detection voltage change rate value, it is determined that “RS phase short circuit has occurred”. To do.
(C) Detection of S-T phase short circuit The 3E relay 70 has a current change rate K _RS (= 1,231) of the combined current I _RS equal to or higher than an overload / short circuit detection current change rate value (eg, 1.15). And the second overload when the voltage change rate L _RS (= 0.954) of the RS phase line voltage V _RS is equal to or less than the first overload / short-circuit detection voltage change rate value (for example, 0.96). The voltage change rate L _ST (= 0.8) of the ST phase line voltage V _ST is greater than the short circuit detection voltage change rate value (for example, 0.8), and the second overload / short circuit detection voltage change. The ST reference phase difference α _ST (= −97 °) of the combined current I _RS is a predetermined first overload / short-circuit detection phase difference range (for example, − When the value is within the range of 150 ° to −90 °, it is determined that “S-T phase short circuit has occurred”.
Further, the 3E relay 70 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the S-phase and T-phase fault currents I _FS and I _FT exceeding the rated current value flow. Is less than the overload / short circuit detection current change rate value (for example, 1.15), the voltage change rate L _ST (= 0.8) of the ST phase line voltage V _ST is the second overload / short circuit The detected voltage change rate value (for example, 0.8) or less and the ST reference phase difference α _ST (= −105 °) of the combined current I _RS is the first overload / short-circuit detection phase difference range (for example, When the value is within the range of −150 ° to −90 °, it is determined that “S-T phase short circuit has occurred”.
(D) Detection of TR phase short circuit The 3E relay 70 has a current change rate K _RS (= 0.183) of the combined current I _RS that is less than an overload / short circuit detection current change rate value (eg, 1.15). Yes, and the voltage change rate L _ST (= 0.954) of the ST phase line voltage V _ST is larger than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and TR Voltage change rate L _TR (= 0.8) of phase-line voltage V _TR is equal to or less than a second overload / short-circuit detection voltage change rate value (for example, 0.8), and TR of composite current I _RS When the reference phase difference α _TR (= −159.6 °) is a value within a predetermined second overload / short-circuit detection phase difference range (for example, −203.1 ° to −90 °), “T− It is determined that an R-phase short circuit has occurred.
Further, the 3E relay 20 has a current change rate K _RS (>> 0.664) of the combined current I _RS because the T-phase and R-phase fault currents I _FT and I _{FR that} are larger than the rated current value flow. Is the overload / short circuit detection current change rate value (for example, 1.15) or more, the voltage change rate L _RS (= 0.954) of the RS phase line voltage V _RS is the first overload / short circuit Voltage change rate of ST phase line-to-line voltage V _{ST that} is equal to or less than detection voltage change rate value (eg, 0.96) and greater than second overload / short-circuit detection voltage change rate value (eg, 0.8) L _ST (= 0.954) is larger than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and the voltage change rate L _TR (= 0) of the TR phase line voltage V _TR .8) a second overload or short circuit detecting voltage change rate value (e.g., 0.8) or less and, T of the resultant current I _RS Reference phase difference α _TR (= -140.2 °) a second overload or short circuit detecting a phase difference range (for example, -203.1 ° ~-90 °) when a value within the "TR phase It is determined that a short circuit has occurred.
(E) Three-phase short circuit detection The 3E relay 70 has a current change rate K _RS (= 1.15) of the combined current I _RS equal to or greater than an overload / short circuit detection current change rate value (eg, 1.15), Further, the voltage change rate L _RS (= 0.8) of the RS phase line voltage V _RS is equal to or less than the second overload / short-circuit detection voltage change rate value (for example, 0.8), and the ST phase line When the voltage change rate L _ST (= 0.8) of the inter-voltage V _ST is equal to or less than the second overload / short circuit detection voltage change rate value, it is determined that “a three-phase short circuit has occurred”.

次に、３Ｅリレー７０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について、図３２を参照して詳しく説明する。   Next, the detection method of the RS reciprocal phase, the ST reciprocal phase, and the TR reciprocal phase in the 3E relay 70 will be described in detail with reference to FIG.

（１）正常時の正常時の合成電流Ｉ_(R-S)0、ＲＳ相線間電圧Ｖ_RS0、ＳＴ相線間電圧Ｖ_ST0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＲＳ相線間電圧Ｖ_RS0の値｜Ｖ_RS0｜および位相θ_RS0と正常時のＳＴ相線間電圧Ｖ_ST0の値｜Ｖ_ST0｜および位相θ_ST0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは上記（４１−１）式から（４１−８）式でそれぞれ表される。
また、正常時のＲＳ相線間電圧Ｖ_RS0のＴＲ基準位相差β_RS0は（４７−１）式で表される。
β_RS0＝θ_RS0−θ_TR0＝３３０°−２１０°＝１２０° （４７−１） (1) Normal combined current I _{(RS) 0} at normal time, RS phase line voltage V _RS0 , ST phase line voltage V _ST0 and TR phase line voltage V _TR0
Normal value of combined current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal RS phase line voltage V _RS0 | V _RS0 | and phase θ _RS0 and normal The value | V _ST0 | and the phase θ _ST0 of the ST phase line voltage V _{ST0 and} the value of the TR phase line voltage V _{TR0 in} the normal state | V _TR0 | and the phase θ _TR0 from the equation (41-1) ( 41-8).
Further, the TR reference phase difference β _RS0 of the RS phase line voltage V _RS0 at the normal time is expressed by the equation (47-1).
β _RS0 = θ _RS0 -θ _TR0 = 330 ° -210 ° = 120 ° (47-1)

（２）Ｒ−Ｓ相反相時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相およびＳ相が逆になる（Ｒ−Ｓ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとは（４８−１）式から（４８−１３）式でそれぞれ表される（図６（ｂ−１），図３２（ａ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （４８−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （４８−２）
θ_R-S＝１５０° （４８−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝３^1/2×｜Ｖ_R｜＝３^1/2×｜Ｖ_R0｜＝３^1/2×１
＝３^1/2 （４８−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝３^1/2／３^1/2＝１ （４８−５）
θ_RS＝１５０° （４８−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝３^1/2×｜Ｖ_S｜＝３^1/2×｜Ｖ_S0｜＝３^1/2×１
＝３^1/2 （４８−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝３^1/2／３^1/2＝１ （４８−８）
θ_ST＝３０° （４８−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （４８−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （４８−１１）
θ_TR＝２７０° （４８−１２）
β_RS＝θ_RS−θ_TR＝１５０°−２７０°＝−１２０° （４８−１３） (2) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR during the R-S phase opposite phase
When the R phase and S phase of the three-phase power supply line are reversed (R-S phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR The value | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the TR reference phase difference β _{RS of the} RS phase line voltage V _RS are expressed by equations (48-1) to (48-13), respectively. (See FIG. 6B-1 and FIG. 32A).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (48-1)
_{K RS = | I RS | /} | I (RS) 0 | = 3 1/2 / 3 1/2 = 1 (48-2)
θ _RS = 150 ° (48-3)
| V _RS | = | V _R −V _S | = 3 ^1/2 × | V _R | = 3 ^1/2 × | V _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (48-4)
_{L RS = | V RS | /} | V RS0 | = 3 1/2 / 3 1/2 = 1 (48-5)
θ _RS = 150 ° (48-6)
| V _ST | = | V _S −V _T | = 3 ^1/2 × | V _S | = 3 ^1/2 × | V _S0 | = 3 ^1/2 × 1
= 3 ^1/2 (48-7)
L _ST = | V _ST | / | V _ST0 | = 3 ^1/2 / 3 ^1/2 = 1 (48-8)
θ _ST = 30 ° (48-9)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (48-10)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (48-11)
θ _TR = 270 ° (48-12)
β _RS = θ _RS −θ _TR = 150 ° -270 ° = −120 ° (48-13)

（３）Ｓ−Ｔ相反相時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相およびＴ相が逆になる（Ｓ−Ｔ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとは（４９−１）式から（４９−１３）式でそれぞれ表される（図７（ａ−１），図３２（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （４９−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （４９−２）
θ_R-S＝３０° （４９−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝３^1/2×｜Ｖ_R｜＝３^1/2×｜Ｖ_R0｜＝３^1/2×１
＝３^1/2 （４９−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝３^1/2／３^1/2＝１ （４９−５）
θ_RS＝３０° （４９−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝３^1/2×｜Ｖ_S｜＝３^1/2×｜Ｖ_S0｜＝３^1/2×１
＝３^1/2 （４９−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝３^1/2／３^1/2＝１ （４９−８）
θ_ST＝２７０° （４９−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （４９−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （４９−１１）
θ_TR＝１５０° （４９−１２）
β_RS＝θ_RS−θ_TR＝３０°−１５０°＝−１２０° （４９−１３） (3) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR during the S-T phase opposite phase
When the S phase and T phase of the three-phase power supply line are reversed (ST phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR The value | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the TR reference phase difference β _{RS of the} RS phase line voltage V _RS are expressed by equations (49-1) to (49-13), respectively. (See FIGS. 7 (a-1) and 32 (b)).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (49-1)
_{K RS = | I RS | /} | I (RS) 0 | = 3 1/2 / 3 1/2 = 1 (49-2)
θ _RS = 30 ° (49-3)
| V _RS | = | V _R −V _S | = 3 ^1/2 × | V _R | = 3 ^1/2 × | V _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (49-4)
L _RS = | V _RS | / | V _RS0 | = 3 ^1/2 / 3 ^1/2 = 1 (49-5)
θ _RS = 30 ° (49-6)
| V _ST | = | V _S −V _T | = 3 ^1/2 × | V _S | = 3 ^1/2 × | V _S0 | = 3 ^1/2 × 1
= 3 ^1/2 (49-7)
L _ST = | V _ST | / | V _ST0 | = 3 ^1/2 / 3 ^1/2 = 1 (49-8)
θ _ST = 270 ° (49-9)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (49-10)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (49-11)
θ _TR = 150 ° (49-12)
β _RS = θ _RS −θ _TR = 30 ° −150 ° = −120 ° (49-13)

（４）Ｔ−Ｒ相反相時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相およびＲ相が逆になる（Ｔ−Ｒ相反相）と、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとは（５０−１）式から（５０−１３）式でそれぞれ表される（図７（ｂ−１），図３２（ｃ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝３^1/2×｜Ｉ_R｜＝３^1/2×｜Ｉ_R0｜＝３^1/2×１
＝３^1/2 （５０−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （５０−２）
θ_R-S＝２７０° （５０−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝３^1/2×｜Ｖ_R｜＝３^1/2×｜Ｖ_R0｜＝３^1/2×１
＝３^1/2 （５０−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝３^1/2／３^1/2＝１ （５０−５）
θ_RS＝２７０° （５０−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝３^1/2×｜Ｖ_S｜＝３^1/2×｜Ｖ_S0｜＝３^1/2×１
＝３^1/2 （５０−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝３^1/2／３^1/2＝１ （５０−８）
θ_ST＝１５０° （５０−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝３^1/2×｜Ｖ_T｜＝３^1/2×｜Ｖ_T0｜＝３^1/2×１
＝３^1/2 （５０−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （５０−１１）
θ_TR＝３０° （５０−１２）
β_RS＝θ_RS−θ_TR＝２７０°−３０°＝２４０°＝−１２０° （５０−１３） (4) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST, and TR phase line voltage V _TR during the TR phase opposite phase
When the T phase and R phase of the three-phase power supply line are reversed (TR phase opposite phase), the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS value | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and TR phase line voltage V _TR The value | V _TR |, the voltage change rate L _{TR, the} phase θ _TR, and the TR reference phase difference β _{RS of the} RS phase line voltage V _RS are expressed by equations (50-1) to (50-13), respectively. (See FIG. 7 (b-1) and FIG. 32 (c)).
| I _RS | = | I _R −I _S | = 3 ^1/2 × | I _R | = 3 ^1/2 × | I _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (50-1)
K _RS = | I _RS | / | I _{(RS) 0} | = 3 ^1/2 / 3 ^1/2 = 1 (50-2)
θ _RS = 270 ° (50-3)
| V _RS | = | V _R −V _S | = 3 ^1/2 × | V _R | = 3 ^1/2 × | V _R0 | = 3 ^1/2 × 1
= 3 ^1/2 (50-4)
L _RS = | V _RS | / | V _RS0 | = 3 ^1/2 / 3 ^1/2 = 1 (50-5)
θ _RS = 270 ° (50-6)
| V _ST | = | V _S −V _T | = 3 ^1/2 × | V _S | = 3 ^1/2 × | V _S0 | = 3 ^1/2 × 1
= 3 ^1/2 (50-7)
L _ST = | V _ST | / | V _ST0 | = 3 ^1/2 / 3 ^1/2 = 1 (50-8)
θ _ST = 150 ° (50-9)
| V _TR | = | V _T −V _R | = 3 ^1/2 × | V _T | = 3 ^1/2 × | V _T0 | = 3 ^1/2 × 1
= 3 ^1/2 (50-10)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (50-11)
θ _TR = 30 ° (50-12)
β _RS = θ _RS −θ _TR = 270 ° −30 ° = 240 ° = −120 ° (50-13)

（５）反相の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が所定の反相検出電流変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）およびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝１）がすべて所定の反相検出電圧変化率範囲（たとえば、０．９〜１．１）内の値であり、かつ、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RS（＝−１２０°）が所定の反相検出位相差範囲（たとえば、−９０°〜−１５０°）内の値であると、「反相が発生した」と判定する。 (5) Detection of opposite phase In the 3E relay 70, the current change rate K _RS (= 1) of the combined current I _RS is a value within a predetermined opposite phase detection current change rate range (for example, 0.9 to 1.1). , and the and the voltage change rate L _RS voltage V _RS between RS phase line (= 1), the voltage change rate L _ST of the voltage V _ST between the ST phase line (= 1) and TR phase line voltage of the voltage V _TR All the change rates L _TR (= 1) are values within a predetermined anti-phase detection voltage change rate range (for example, 0.9 to 1.1), and the TR reference phase difference of the RS phase line voltage V _RS If β _RS (= −120 °) is a value within a predetermined anti-phase detection phase difference range (for example, −90 ° to −150 °), it is determined that “an anti-phase has occurred”.

次に、３Ｅリレー７０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について、図３３を参照して詳しく説明する。   Next, FIG. 33 shows a method for detecting the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase disconnections of the star-connected three-phase power supply line in the 3E relay 70. This will be described in detail with reference.

（１）正常時の正常時の合成電流Ｉ_(R-S)0、ＲＳ相線間電圧Ｖ_RS0、ＳＴ相線間電圧Ｖ_ST0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＲＳ相線間電圧Ｖ_RS0の値｜Ｖ_RS0｜および位相θ_RS0と正常時のＳＴ相線間電圧Ｖ_ST0の値｜Ｖ_ST0｜および位相θ_ST0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは上記（４１−１）式から（４１−８）式でそれぞれ表される。
また、正常時のＲＳ相線間電圧Ｖ_RS0のＴＲ基準位相差β_RS0と正常時のＳＴ相線間電圧Ｖ_ST0のＲＳ基準位相差β_ST0と正常時のＴＲ相線間電圧Ｖ_TR0のＳＴ基準位相差β_TR0とは（５１−１）式から（５１−３）式で表される。
β_RS0＝θ_RS0−θ_TR0＝３３０°−２１０°＝１２０° （５１−１）
β_ST0＝θ_ST0−θ_RS0＝９０°−３３０°＝−２４０°＝１２０° （５１−２）
β_TR0＝θ_TR0−θ_ST0＝２１０°−９０°＝１２０° （５１−３） (1) Normal combined current I _{(RS) 0} at normal time, RS phase line voltage V _RS0 , ST phase line voltage V _ST0 and TR phase line voltage V _TR0
Normal value of combined current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal RS phase line voltage V _RS0 | V _RS0 | and phase θ _RS0 and normal The value | V _ST0 | and the phase θ _ST0 of the ST phase line voltage V _{ST0 and} the value of the TR phase line voltage V _{TR0 in} the normal state | V _TR0 | and the phase θ _TR0 from the equation (41-1) ( 41-8).
In addition, the TR reference phase difference β _RS0 of the RS phase line voltage V _{RS0 in} the normal state and the ST reference phase difference β _ST0 of the ST phase line voltage V _{ST0 in} the normal state and the ST of the TR phase line voltage V _{TR0 in} the normal state The reference phase difference β _TR0 is expressed by equations (51-1) to (51-3).
β _RS0 = θ _RS0 -θ _TR0 = 330 ° -210 ° = 120 ° (51-1)
β _ST0 = θ _ST0 -θ _RS0 = 90 ° -330 ° = -240 ° = 120 ° (51-2)
β _TR0 = θ _TR0 −θ _ST0 = 210 ° -90 ° = 120 ° (51-3)

（２）Ｒ相欠相時の合成電流Ｉ_R-S、、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相の欠相（Ｒ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STとＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRとは（５２−１）式から（５２−１５）式でそれぞれ表される（図８（ｂ−１），図３３（ａ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_S｜＝｜Ｉ_S0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （５２−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2／２）／３^1/2＝０．５ （５２−２）
θ_R-S＝２７０° （５２−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝｜Ｖ_S｜＝｜Ｖ_S0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （５２−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝（３^1/2／２）／３^1/2＝０．５ （５２−５）
θ_RS＝２７０° （５２−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝｜Ｖ_S｜＋｜Ｖ_T｜
＝（｜Ｖ_S0｜×ｃｏｓ３０°）＋（｜Ｖ_T0｜×ｃｏｓ３０°）
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （５２−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝３^1/2／３^1/2＝１ （５２−８）
θ_ST＝９０° （５２−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_T｜＝｜Ｖ_T0｜×ｃｏｓ３０°
＝１×（３^1/2／２）＝３^1/2／２ （５２−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（３^1/2／２）／３^1/2＝０．５ （５２−１１）
θ_TR＝２７０° （５２−１２）
β_RS＝θ_RS−θ_TR＝２７０°−２７０°＝０° （５２−１３）
β_ST＝θ_ST−θ_RS＝９０°−２７０°＝−１８０°＝１８０° （５２−１４）
β_TR＝θ_TR−θ_ST＝２７０°−９０°＝１８０° （５２−１５） (2) Composite current I _RS at the time of R phase loss, RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR
When phase failure of the R-phase of the three-phase power line (R Aiketsusho) occurs, the resultant current I _RS value | I _RS |, the current change rate K _RS and the phase theta _RS and the value of the voltage V _RS between RS phase line | V _RS |, voltage change rate L _RS and value of phase θ _RS and ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and value of TR phase line voltage V _TR | V _TR |, voltage change rate L _TR and phase θ _TR and RS phase line voltage V _RS TR reference phase difference β _RS and ST phase line voltage V _ST RS reference phase difference β _ST and TR phase line voltage V _TR The ST reference phase difference β _TR is expressed by the equations (52-1) to (52-15) (see FIGS. 8B-1 and 33A).
| I _RS | = | I _R −I _S | = | I _S | = | I _S0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (52-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (52-2)
θ _RS = 270 ° (52-3)
_{| V RS | = | V R} -V S | = | V S | = | V S0 | × cos30 ° = 1 × (3 1/2 / 2)
= 3 ^1/2 / 2 (52-4)
L _RS = | V _RS | / | V _RS0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (52-5)
θ _RS = 270 ° (52-6)
| V _ST | = | V _S −V _T | = | V _S | + | V _T |
= (| V _S0 | × cos 30 °) + (| V _T0 | × cos 30 °)
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (52-7)
L _ST = | V _ST | / | V _ST0 | = 3 ^1/2 / 3 ^1/2 = 1 (52-8)
θ _ST = 90 ° (52-9)
| V _TR | = | V _T −V _R | = | V _T | = | V _T0 | × cos 30 °
^{= 1 × (3 1/2 / 2} ) = 3 1/2 / 2 (52-10)
L _TR = | V _TR | / | V _TR0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (52-11)
θ _TR = 270 ° (52-12)
β _RS = θ _RS −θ _TR = 270 ° -270 ° = 0 ° (52-13)
β _ST = θ _ST −θ _RS = 90 ° -270 ° = −180 ° = 180 ° (52-14)
β _TR = θ _TR −θ _ST = 270 ° -90 ° = 180 ° (52-15)

（３）Ｓ相欠相時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相の欠相（Ｓ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STとＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRとは（５３−１）式から（５３−１５）式でそれぞれ表される（図９（ａ−１），図３３（ｂ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_R｜＝｜Ｉ_R0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （５３−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝（３^1/2／２）／３^1/2＝０．５ （５３−２）
θ_R-S＝３０° （５３−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_S｜＝｜Ｖ_R｜＝｜Ｖ_R0｜×ｃｏｓ３０°＝１×（３^1/2／２）
＝３^1/2／２ （５３−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝（３^1/2／２）／３^1/2＝０．５ （５３−５）
θ_RS＝３０° （５３−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝｜Ｖ_T｜＝｜Ｖ_T0｜×ｃｏｓ３０°
＝１×（３^1/2／２）＝３^1/2／２ （５３−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝（３^1/2／２）／３^1/2＝０．５ （５３−８）
θ_ST＝３０° （５３−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_T｜＋｜Ｖ_R｜
＝（｜Ｖ_T0｜×ｃｏｓ３０°）＋（｜Ｖ_R0｜×ｃｏｓ３０°）
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （５３−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝３^1/2／３^1/2＝１ （５３−１１）
θ_TR＝２１０° （５３−１２）
β_RS＝θ_RS−θ_TR＝３０°−２１０°＝−１８０°＝１８０° （５３−１３）
β_ST＝θ_ST−θ_RS＝３０°−３０°＝０° （５３−１４）
β_TR＝θ_TR−θ_ST＝２１０°−３０°＝１８０° （５３−１５） (3) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when S phase is open
When an S-phase phase loss (S-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS and the RS phase line voltage V _RS | V _RS |, voltage change rate L _RS and phase θ _RS and value of ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and value of TR phase line voltage V _TR | V _TR |, voltage change rate L _TR and phase θ _TR and RS phase line voltage V _RS TR reference phase difference β _RS and ST phase line voltage V _ST RS reference phase difference β _ST and TR phase line voltage V _TR The ST reference phase difference β _TR is expressed by equations (53-1) to (53-15) (see FIGS. 9 (a-1) and 33 (b)).
| I _RS | = | I _R −I _S | = | I _R | = | I _R0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (53-1)
K _RS = | I _RS | / | I _{(RS) 0} | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (53-2)
θ _RS = 30 ° (53-3)
| V _RS | = | V _R −V _S | = | V _R | = | V _R0 | × cos 30 ° = 1 × (3 ^1/2 / 2)
= 3 ^1/2 / 2 (53-4)
L _RS = | V _RS | / | V _RS0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (53-5)
θ _RS = 30 ° (53-6)
| V _ST | = | V _S −V _T | = | V _T | = | V _T0 | × cos 30 °
= 1 × (3 ^1/2 / 2) = 3 ^1/2 / 2 (53-7)
L _ST = | V _ST | / | V _ST0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (53-8)
θ _ST = 30 ° (53-9)
| V _TR | = | V _T −V _R | = | V _T | + | V _R |
= (| V _T0 | × cos 30 °) + (| V _R0 | × cos 30 °)
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (53-10)
L _TR = | V _TR | / | V _TR0 | = 3 ^1/2 / 3 ^1/2 = 1 (53-11)
θ _TR = 210 ° (53-12)
β _RS = θ _RS −θ _TR = 30 ° −210 ° = −180 ° = 180 ° (53-13)
β _ST = θ _ST −θ _RS = 30 ° -30 ° = 0 ° (53-14)
β _TR = θ _TR −θ _ST = 210 ° −30 ° = 180 ° (53-15)

（４）Ｔ相欠相時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相の欠相（Ｔ相欠相）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-SとＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSとＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STとＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRとは（５４−１）式から（５４−１５）式でそれぞれ表される（図９（ｂ−１），図３３（ｃ）参照）。
｜Ｉ_R-S｜＝｜Ｉ_R−Ｉ_S｜＝｜Ｉ_R｜＋｜Ｉ_S｜
＝｜Ｉ_R0｜×ｃｏｓ３０°＋｜Ｉ_S0｜×ｃｏｓ３０°
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （５４−１）
Ｋ_R-S＝｜Ｉ_R-S｜／｜Ｉ_(R-S)0｜＝３^1/2／３^1/2＝１ （５４−２）
θ_R-S＝３３０° （５４−３）
｜Ｖ_RS｜＝｜Ｖ_R−Ｖ_T｜＝｜Ｖ_R｜＋｜Ｖ_T｜
＝（｜Ｖ_R0｜×ｃｏｓ３０°）＋（｜Ｖ_T0｜×ｃｏｓ３０°）
＝｛１×（３^1/2／２）｝＋｛１×（３^1/2／２）｝
＝２×｛１×（３^1/2／２）｝＝３^1/2 （５４−４）
Ｌ_RS＝｜Ｖ_RS｜／｜Ｖ_RS0｜＝３^1/2／３^1/2＝１ （５４−５）
θ_RS＝３３０° （５４−６）
｜Ｖ_ST｜＝｜Ｖ_S−Ｖ_T｜＝｜Ｖ_S｜＝｜Ｖ_S0｜×ｃｏｓ３０°
＝１×（３^1/2／２）＝３^1/2／２ （５４−７）
Ｌ_ST＝｜Ｖ_ST｜／｜Ｖ_ST0｜＝（３^1/2／２）／３^1/2＝０．５ （５４−８）
θ_ST＝１５０° （５４−９）
｜Ｖ_TR｜＝｜Ｖ_T−Ｖ_R｜＝｜Ｖ_R｜＝｜Ｖ_R0｜×ｃｏｓ３０°
＝１×（３^1/2／２）＝３^1/2／２ （５４−１０）
Ｌ_TR＝｜Ｖ_TR｜／｜Ｖ_TR0｜＝（３^1/2／２）／３^1/2＝０．５ （５４−１１）
θ_TR＝１５０° （５４−１２）
β_RS＝θ_RS−θ_TR＝３３０°−１５０°＝１８０° （５４−１３）
β_ST＝θ_ST−θ_RS＝１５０°−３３０°＝−１８０°＝１８０° （５４−１４）
β_TR＝θ_TR−θ_ST＝１５０°−１５０°＝０° （５４−１５） (4) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when T phase is open
When a T-phase phase loss (T-phase phase loss) occurs in the three-phase power line, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the value of the phase θ _RS and the RS phase line voltage V _RS | V _RS |, voltage change rate L _RS and phase θ _RS and value of ST phase line voltage V _ST | V _ST |, voltage change rate L _ST and phase θ _ST and value of TR phase line voltage V _TR | V _TR |, voltage change rate L _TR and phase θ _TR and RS phase line voltage V _RS TR reference phase difference β _RS and ST phase line voltage V _ST RS reference phase difference β _ST and TR phase line voltage V _TR The ST reference phase difference β _TR is expressed by the equations (54-1) to (54-15) (see FIGS. 9 (b-1) and 33 (c)).
| I _RS | = | I _R −I _S | = | I _R | + | I _S |
= | I _R0 | × cos 30 ° + | I _S0 | × cos 30 °
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (54-1)
_{K RS = | I RS | /} | I (RS) 0 | = 3 1/2 / 3 1/2 = 1 (54-2)
θ _RS = 330 ° (54-3)
| V _RS | = | V _R −V _T | = | V _R | + | V _T |
= (| V _R0 | × cos 30 °) + (| V _T0 | × cos 30 °)
= {1 × (3 ^1/2 / 2)} + {1 × (3 ^1/2 / 2)}
= 2 × {1 × (3 ^1/2 / 2)} = 3 ^1/2 (54-4)
L _RS = | V _RS | / | V _RS0 | = 3 ^1/2 / 3 ^1/2 = 1 (54-5)
θ _RS = 330 ° (54-6)
| V _ST | = | V _S −V _T | = | V _S | = | V _S0 | × cos 30 °
= 1 × (3 ^1/2 / 2) = 3 ^1/2 / 2 (54-7)
L _ST = | V _ST | / | V _ST0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (54-8)
θ _ST = 150 ° (54-9)
| V _TR | = | V _T −V _R | = | V _R | = | V _R0 | × cos 30 °
= 1 × (3 ^1/2 / 2) = 3 ^1/2 / 2 (54-10)
L _TR = | V _TR | / | V _TR0 | = (3 ^1/2 / 2) / 3 ^1/2 = 0.5 (54-11)
θ _TR = 150 ° (54-12)
β _RS = θ _RS −θ _TR = 330 ° -150 ° = 180 ° (54-13)
β _ST = θ _ST −θ _RS = 150 ° −330 ° = −180 ° = 180 ° (54-14)
β _TR = θ _TR −θ _ST = 150 ° −150 ° = 0 ° (54-15)

（５）Ｒ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲ相の断線（Ｒ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（５２−１）式から（５２−３）式でそれぞれ表され、ＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは上記（４２−４）式から（４２−１２）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＴＲ基準位相差α_TRは（５５−１）式で表される。
α_TR＝θ_R-S−θ_TR＝２７０°−２１０°＝６０° （５５−１） (5) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when R phase is disconnected
When disconnection of the R-phase of the three-phase power line (R-phase disconnection) occurs, the resultant current value of I _RS | I _RS |, the current change rate K _RS and the phase theta _RS from the (52-1) Formula (52- 3) The values of RS phase line voltage V _RS | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST value | V _ST |, voltage change rate L _{The value of the ST} and phase θ _ST and TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the equations (42-4) to (42-12), respectively. .
The TR reference phase difference α _TR of the combined current I _RS is expressed by the formula (55-1).
α _TR = θ _RS −θ _TR = 270 ° −210 ° = 60 ° (55-1)

（６）Ｓ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳ相の断線（Ｓ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（５３−１）式から（５３−３）式でそれぞれ表され、ＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは上記（４２−４）式から（４２−１２）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＴＲ基準位相差α_TRは（５５−２）式で表される。
α_TR＝θ_R-S−θ_TR＝３０°−２１０°＝−１８０°＝１８０° （５５−２） (6) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when S phase is broken
When the S-phase disconnection (S-phase disconnection) of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are calculated from the above equation (53-1) (53− 3) The values of RS phase line voltage V _RS | V _RS |, voltage change rate L _RS and phase θ _RS and ST phase line voltage V _ST value | V _ST |, voltage change rate L the value of the _ST and the phase theta _ST and TR phase line voltage V _TR | V _TR |, respectively represented by the above (42-4) expression (42-12) where the voltage change rate L _TR and the phase theta _TR .
The TR reference phase difference α _TR of the combined current I _RS is expressed by the formula (55-2).
α _TR = θ _RS −θ _TR = 30 ° -210 ° = −180 ° = 180 ° (55-2)

（７）Ｔ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴ相の断線（Ｔ相断線）が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（５４−１）式から（５４−３）式でそれぞれ表され
とＲＳ相線間電圧Ｖ_RSの値｜Ｖ_RS｜、電圧変化率Ｌ_RSおよび位相θ_RSとＳＴ相線間電圧Ｖ_STの値｜Ｖ_ST｜、電圧変化率Ｌ_STおよび位相θ_STとＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRとは上記（４２−４）式から（４２−１２）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＴＲ基準位相差α_TRは（５５−３）式で表される。
α_TR＝θ_R-S−θ_TR＝３３０°−２１０°＝１２０° （５５−３） (7) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when T phase is broken
When the T-phase disconnection (T-phase disconnection) of the three-phase power supply line occurs, the value | I _RS | of the combined current I _RS , the current change rate K _RS and the phase θ _RS are expressed by the equation 3) each represented by the formula the value of the voltage V _RS between RS phase line | V _RS |, the voltage change rate L _RS and the phase theta _RS and ST-phase line voltage V values of _ST | V _ST |, the voltage change rate L _{The value of the ST} and phase θ _ST and TR phase line voltage V _TR | V _TR |, the voltage change rate L _TR and the phase θ _TR are expressed by the equations (42-4) to (42-12), respectively. .
The TR reference phase difference α _TR of the combined current I _RS is expressed by the equation (55-3).
α _TR = θ _RS −θ _TR = 330 ° -210 ° = 120 ° (55-3)

（８）Ｒ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出
（ａ）Ｒ相欠相の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．５）およびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が共に所定の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が欠相・断線検出電圧変化率範囲内の値でなく、かつ、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RS（＝０°）が所定の欠相検出位相差範囲（たとえば、−３０°〜３０°）内の値であると、「Ｒ相欠相が発生した」と判定する。
（ｂ）Ｓ相欠相の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝０．５）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．５）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、ＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_ST（＝０°）が欠相検出位相差範囲（たとえば、−３０°〜３０°）内の値であると、「Ｓ相欠相が発生した」と判定する。
（ｃ）Ｔ相欠相の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）が欠相・断線検出電圧変化率範囲内の値でなく、かつ、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝０．５）およびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TR（＝０．５）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、Ｒ相線間電圧Ｖ_TRのＴＲ基準位相差β_TR（＝０°）が欠相検出位相差範囲（たとえば、−３０°〜３０°）内の値であると、「Ｔ相欠相が発生した」と判定する。
（ｄ）Ｒ相断線の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が所定の断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝６０°）が所定の第１の断線検出位相差範囲（たとえば、３０°〜９０°）内の値であると、「Ｒ相断線が発生した」と判定する。
（ｅ）Ｓ相断線の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．５）が断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値であり、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝１８０°）が所定の第２の断線検出位相差範囲（たとえば、１５０°〜２１０°）内の値であると、「Ｓ相断線が発生した」と判定する。
（ｆ）Ｔ相断線の検出
３Ｅリレー７０は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝１）が断線検出電流変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝１２０°）が所定の第３の断線検出位相差範囲（たとえば、９０°〜１５０°）内の値であると、「Ｔ相断線が発生した」と判定する。 (8) Detection of R phase open phase, S phase open phase, T phase open phase, R phase open phase, S phase open phase and T phase open phase (a) Detection of R phase open phase 3E relay 70 is RS phase line voltage voltage change rate L _RS of V _RS (= 0.5) and TR the voltage change rate of the phase line voltage V _TR L _TR (= 0.5) are both predetermined phase loss-disconnection detecting voltage change rate ranges (e.g., 0.4 to 0.6), and the voltage change rate L _ST (= 1) of the ST phase line-to-line voltage V _ST is not a value within the phase loss / breakage detection voltage change rate range, and When the TR reference phase difference β _RS (= 0 °) of the RS phase line voltage V _RS is a value within a predetermined phase loss detection phase difference range (for example, −30 ° to 30 °), It is determined that a phase has occurred.
(B) Detection of S-phase phase loss The 3E relay 70 has a voltage change rate L _RS (= 0.5) of the RS phase line voltage V _RS and a voltage change rate L _ST (= 0) of the ST phase line voltage V _ST. .5) are both values within the phase loss / breakage detection voltage change rate range (for example, 0.4 to 0.6), and the RS reference phase difference β _ST (= 0) of the ST phase line voltage V _ST (°) is a value within a phase loss detection phase difference range (for example, −30 ° to 30 °), it is determined that “S phase phase loss has occurred”.
(C) Detection of T-phase phase loss The 3E relay 70 has a voltage change rate L _RS (= 1) of the RS phase line-to-line voltage V _RS that is not within the range of the phase loss / breakage detection voltage change rate range, and ST voltage change rate of the phase line voltage V _ST L _ST (= 0.5) and the voltage change rate of the TR-phase line voltage V _TR L _TR (= 0.5) are both open phase-disconnection detecting voltage change rate ranges ( For example, the value is within a range of 0.4 to 0.6), and the TR reference phase difference β _TR (= 0 °) of the R-phase line-to-line voltage V _TR is in the open phase detection phase difference range (for example, −30 ° If the value is within the range of ˜30 °, it is determined that “T phase phase loss has occurred”.
(D) detecting 3E relay 70 of the R-phase disconnection, the voltage change rate L _RS voltage V _RS between RS phase line (= 1) and the voltage change rate L _ST of the voltage V _ST between the ST phase line (= 1) are both The current change rate K _RS (= 0.5) of the composite current I _RS is not a value within the phase loss / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the predetermined disconnection detection current. It is a value within a change rate range (for example, 0.4 to 0.6), and the TR reference phase difference α _TR (= 60 °) of the combined current I _RS is a predetermined first disconnection detection phase difference range ( For example, if the value is within a range of 30 ° to 90 °, it is determined that “R-phase disconnection has occurred”.
(E) detecting 3E relay 70 of the S-phase disconnection, the voltage change rate L _RS voltage V _RS between RS phase line (= 1) and the voltage change rate L _ST of the voltage V _ST between the ST phase line (= 1) are both The current change rate K _RS (= 0.5) of the combined current I _RS is not a value within the phase loss / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the disconnection detection current change rate. The TR reference phase difference α _TR (= 180 °) of the combined current I _RS is a value within a range (eg, 0.4 to 0.6), and a predetermined second disconnection detection phase difference range (eg, If the value is within the range of 150 ° to 210 °, it is determined that “S phase disconnection has occurred”.
Detection 3E relay 70 (f) T-phase disconnection, the voltage change rate L _RS voltage V _RS between RS phase line (= 1) and the voltage change rate L _ST of the voltage V _ST between the ST phase line (= 1) are both The current change rate K _RS (= 1) of the combined current I _RS is not a value within the phase loss / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the disconnection detection current change rate range ( For example, the value is not within the range of 0.4 to 0.6), and the TR reference phase difference α _TR (= 120 °) of the combined current I _RS is a predetermined third disconnection detection phase difference range (for example, 90 ° If the value is within the range of ~ 150 °, it is determined that “T-phase disconnection has occurred”.

次に、３Ｅリレー７０におけるデルタ結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出方法について詳しく説明する。   Next, a method for detecting the R-phase, S-phase, T-phase, RS-phase, ST-phase, and TR-phase disconnections of the delta-connected three-phase power supply line in the 3E relay 70 will be described in detail.

（１）正常時の合成電流Ｉ_(R-S)0、ＲＳ相線間電圧Ｖ_RS0、ＳＴ相線間電圧Ｖ_ST0およびＴＲ相線間電圧Ｖ_TR0
正常時の合成電流Ｉ_(R-S)0の値｜Ｉ_(R-S)0｜および位相θ_(R-S)0と正常時のＲＳ相線間電圧Ｖ_RS0の値｜Ｖ_RS0｜および位相θ_RS0と正常時のＳＴ相線間電圧Ｖ_ST0の値｜Ｖ_ST0｜および位相θ_ST0と正常時のＴＲ相線間電圧Ｖ_TR0の値｜Ｖ_TR0｜および位相θ_TR0とは上記（４１−１）式から（４１−８）式でそれぞれ表される。
また、正常時のＲＳ相線間電圧Ｖ_RS0のＴＲ基準位相差β_RS0とＳＴ相線間電圧Ｖ_ST0のＲＳ基準位相差β_ST0とＴＲ相線間電圧Ｖ_TR0のＳＴ基準位相差β_TR0とは上記（５１−１）式から（５１−３）式で表される。 (1) Composite current I _{(RS) 0} at normal time, RS phase line voltage V _RS0 , ST phase line voltage V _ST0 and TR phase line voltage V _TR0
Normal value of combined current I _{(RS) 0} | I _{(RS) 0} | and phase θ _{(RS) 0} and normal RS phase line voltage V _RS0 | V _RS0 | and phase θ _RS0 and normal The value | V _ST0 | and the phase θ _ST0 of the ST phase line voltage V _{ST0 and} the value of the TR phase line voltage V _{TR0 in} the normal state | V _TR0 | and the phase θ _TR0 from the equation (41-1) ( 41-8).
Further, the TR reference phase difference beta _RS0 and ST reference phase difference beta _TR0 of RS reference phase difference beta _ST0 and TR phase line voltage V _TR0 the ST phase line voltage V _ST0 of RS-phase line voltage V _RS0 of normal Is represented by the above equations (51-1) to (51-3).

（２）Ｒ相欠相、Ｓ相欠相およびＴ相欠相の検出
３Ｅリレー７０は、上述したスター結線された三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相の検出と同様にして、三相電源線のＲ相欠相、Ｓ相欠相およびＴ相欠相を検出する。 (2) Detection of R-phase, S-phase, and T-phase missing 3E relay 70 detects the R-phase, S-phase, and T-phase missing phases of the star-connected three-phase power line. Similarly to the detection, the R-phase missing phase, the S-phase missing phase, and the T-phase missing phase of the three-phase power supply line are detected.

（３）ＲＳ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＲＳ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１４−１）式から（１４−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＳＴ基準位相差α_TRは（５６−１）式で表される。
α_TR＝θ_R-S−θ_TR＝３３０°−２１０°＝１２０° （５６−１） (3) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when RS phase is broken
When the RS phase disconnection of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are expressed by the above equations (14-1) to (14-3), respectively. The value | V _TR | of the TR phase line voltage V _TR , the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively.
Further, the ST reference phase difference α _TR of the combined current I _RS is expressed by the equation (56-1).
α _TR = θ _RS −θ _TR = 330 ° -210 ° = 120 ° (56-1)

（４）ＳＴ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＳＴ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１５−１）式から（１５−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＳＴ基準位相差α_TRは（５６−２）式で表される。
α_TR＝θ_R-S−θ_TR＝３４９．１°−２１０°＝１３９．１° （５６−２） (4) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when ST phase is disconnected
When the ST phase disconnection of the three-phase power line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are expressed by the above equations (15-1) to (15-3), respectively. The value | V _TR | of the TR phase line voltage V _TR , the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively.
Further, the ST reference phase difference α _TR of the combined current I _RS is expressed by the equation (56-2).
α _TR = θ _RS −θ _TR = 349.1 ° -210 ° = 139.1 ° (56-2)

（４）ＴＲ相断線時の合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TR
三相電源線のＴＲ相断線が発生すると、合成電流Ｉ_R-Sの値｜Ｉ_R-S｜、電流変化率Ｋ_R-Sおよび位相θ_R-Sは上記（１６−１）式から（１６−３）式でそれぞれ表され、ＴＲ相線間電圧Ｖ_TRの値｜Ｖ_TR｜、電圧変化率Ｌ_TRおよび位相θ_TRは上記（２−４）式から（２−６）式でそれぞれ表される。
また、合成電流Ｉ_R-SのＳＴ基準位相差α_TRは（５６−３）式で表される。
α_TR＝θ_R-S−θ_TR＝３１０．９°−２１０°＝１００．９° （５６−３） (4) Composite current I _RS , RS phase line voltage V _RS , ST phase line voltage V _ST and TR phase line voltage V _TR when TR phase is disconnected
When the TR phase disconnection of the three-phase power supply line occurs, the value of the combined current I _RS | I _RS |, the current change rate K _RS and the phase θ _RS are expressed by the above equations (16-1) to (16-3), respectively. The value | V _TR | of the TR phase line voltage V _TR , the voltage change rate L _TR and the phase θ _TR are expressed by the above equations (2-4) to (2-6), respectively.
Further, the ST reference phase difference α _TR of the combined current I _RS is expressed by the equation (56-3).
α _TR = θ _RS −θ _TR = 310.9 ° −210 ° = 100.9 ° (56-3)

（５）ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出
（ａ）ＲＳ相断線の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．３３３）が所定の第１の断線検出電流変化率範囲（たとえば、０．２〜０．４）内の値であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でないと、「ＲＳ相断線が発生した」と判定する。
（ｂ）ＳＴ相断線の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が所定の第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝１３９．１°）が所定の第４の断線検出位相差範囲（たとえば、１３０°〜１５０°）内の値であると、「ＳＴ相断線が発生した」と判定する。
（ｃ）ＴＲ相断線の検出
３Ｅリレー７０は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-S（＝０．８８２）が第２の断線検出電流変化率範囲（たとえば、０．８〜０．９）内の値であり、かつ、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS（＝１）およびＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_ST（＝１）が共に第１の欠相・断線検出電圧変化率範囲（たとえば、０．４〜０．６）内の値でなく、かつ、合成電流Ｉ_R-SのＴＲ基準位相差α_TR（＝１００．９°）が所定の第５の断線検出位相差範囲（たとえば、９０°〜１１０°）内の値であると、「ＴＲ相断線が発生した」と判定する。 (5) RS-phase disconnection detection 3E relay 70 of the ST phase disconnection and detection of TR-phase disconnection (a) RS phase disconnection, combined current I _RS of the current rate of change K _RS (= 0.333) first reaches a predetermined Is a value within the disconnection detection current change rate range (for example, 0.2 to 0.4), the voltage change rate L _RS (= 1) of the RS phase line voltage V _RS and the ST phase line voltage V _{If the ST} voltage change rate L _ST (= 1) is not a value within the phase loss / breakage detection voltage change rate range (for example, 0.4 to 0.6), it is determined that “RS phase breakage has occurred”. .
(B) Detection of ST phase disconnection In the 3E relay 70, the current change rate K _RS (= 0.882) of the combined current I _RS has a predetermined second disconnection detection current change rate range (for example, 0.8 to 0. 0). 9) the value of the, and the voltage change rate L _RS voltage V _RS between RS phase line (= 1) and the voltage change rate L _ST of the ST phase line voltage V _ST (= 1) is first both The TR reference phase difference α _TR (= 139.1 °) of the combined current I _RS is not a value within the open phase / disconnection detection voltage change rate range (for example, 0.4 to 0.6), and the predetermined first If the value is within a disconnection detection phase difference range of 4 (for example, 130 ° to 150 °), it is determined that “ST phase disconnection has occurred”.
(C) Detection of TR phase disconnection In the 3E relay 70, the current change rate K _RS (= 0.882) of the combined current I _RS has a second disconnection detection current change rate range (for example, 0.8 to 0.9). is the value of the inner and the voltage change rate of the voltage V _RS between RS phase line L _RS (= 1) and the voltage change rate of the voltage V _ST between the ST phase line L _ST (= one) are both first open phase A value not within the disconnection detection voltage change rate range (for example, 0.4 to 0.6) and the TR reference phase difference α _TR (= 100.9 °) of the combined current I _RS is a predetermined fifth If the value is within the disconnection detection phase difference range (for example, 90 ° to 110 °), it is determined that “TR phase disconnection has occurred”.

次に、３Ｅリレー７０の構成について、図３４を参照して説明する。
３Ｅリレー７０は、図３４に示すように、入力変換器７１と、アナログ入力部７２と、メモリ７３と、電流変化率算出部７４と、電圧変化率算出部７５と、位相差算出部７６と、リレー演算処理部７７と、整定・表示部７８と、入出部７９と、外部機器Ｉ／Ｆ部８０とを備える。 Next, the configuration of the 3E relay 70 will be described with reference to FIG.
As shown in FIG. 34, the 3E relay 70 includes an input converter 71, an analog input unit 72, a memory 73, a current change rate calculation unit 74, a voltage change rate calculation unit 75, and a phase difference calculation unit 76. A relay calculation processing unit 77, a settling / display unit 78, an input / output unit 79, and an external device I / F unit 80.

ここで、入力変換器７１は、クロス貫通変流器６１から入力される合成電流Ｉ_R-Sおよび計器用変成器６２から入力されるＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRのレベルをアナログ入力部７２の処理に適したレベルに変換する。
アナログ入力部７２は、バンドパスフィルタとサンプリングホールド回路とマルチプレクサ回路とアナログ／ディジタル変換器とを備え、入力変換器７１から入力されるアナログの合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRをディジタルの合成電流Ｉ_R-S、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRに変換する。
メモリ７３は、アナログ入力部７２によってディジタルデータに変換されたＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRを格納するためのものである。 Here, the input converter 71 includes the combined current I _RS input from the cross-through current transformer 61 and the RS phase line voltage V _RS , the ST phase line voltage V _ST and TR input from the instrument transformer 62. The level of the phase-line voltage V _TR is converted to a level suitable for processing of the analog input unit 72.
The analog input unit 72 includes a band pass filter, a sampling hold circuit, a multiplexer circuit, and an analog / digital converter. The analog combined current I _RS , RS phase line voltage V _RS , ST input from the input converter 71 is provided. converting the phase line voltage V _ST and TR phase line voltage V _TR digital composite current I _RS, RS phase line voltage V _RS, ST and phase line voltage V _ST and TR phase line voltage V _TR.
The memory 73 is for storing the RS phase line voltage V _RS , the ST phase line voltage V _ST, and the TR phase line voltage V _TR converted into digital data by the analog input unit 72.

電流変化率算出部７４は、メモリ７３に格納されているＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値に基づいて、アナログ入力部７２から入力される合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sを算出する。 The current change rate calculation unit 74 is a composite current input from the analog input unit 72 based on the rated current values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T stored in the memory 73. calculating a current change rate K _RS of I _RS.

電圧変化率算出部７５は、メモリ７３に格納されているＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値に基づいて、アナログ入力部７２から入力されるＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRを算出する。 The voltage change rate calculation unit 75 is an RS phase input from the analog input unit 72 based on the rated voltage values of the R-phase, S-phase, and T-phase voltages V _R , V _S , and V _T stored in the memory 73. calculated line voltage V _RS, the voltage change rate L _RS voltage V _ST and TR phase line voltage V _TR between ST phase line, L _ST, the L _TR.

位相差算出部７６は、アナログ入力部７２から入力される合成電流Ｉ_R-Sの位相θ_R-Sからアナログ入力部７２から入力されるＳＴ相線間電圧Ｖ_STの位相θ_STを引くことにより合成電流Ｉ_R-SのＳＴ基準位相差α_STを算出するとともに、合成電流Ｉ_R-Sの位相θ_R-Sからアナログ入力部７２から入力されるＴＲ相線間電圧Ｖ_TRの位相θ_TRを引くことにより合成電流Ｉ_R-SのＴＲ基準位相差α_TRを算出する。
また、位相差算出部７６は、ＲＳ相線間電圧Ｖ_RSの位相θ_RSからＴＲ相線間電圧Ｖ_TRの位相θ_TRを引くことによりＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSを算出し、ＳＴ相線間電圧Ｖ_STの位相θ_STからＲＳ相線間電圧Ｖ_RSの位相θ_RSを引くことによりＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STを算出するとともに、ＴＲ相線間電圧Ｖ_TRの位相θ_TRからＳＴ相線間電圧Ｖ_STの位相θ_STを引くことによりＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRを算出する。 The phase difference calculation unit 76 subtracts the phase θ _ST of the ST phase line voltage V _ST input from the analog input unit 72 from the phase θ _RS of the combined current I _RS input from the analog input unit 72 to thereby generate the combined current I _RS. calculates the ST reference phase difference alpha _ST of _RS, the combined current I _RS by subtracting the phase theta _TR synthetic current I _RS in phase theta TR phase line voltage V _TR inputted from the analog input unit 72 from the _RS The TR reference phase difference α _TR is calculated.
Further, the phase difference calculating section 76, TR reference phase difference of RS-phase line voltage V _RS by subtracting the phase theta _TR of TR-phase line voltage V _TR from the phase theta _RS voltage V _RS between RS phase line beta _RS is calculated, to calculate the RS reference phase difference beta _ST voltage V _ST between the ST phase line by subtracting the phase theta _RS voltage V _RS between RS phase line from the phase theta _ST voltage V _ST between the ST phase line, calculating the ST reference phase difference beta _TR of TR-phase line voltage V _TR by the phase theta _TR of TR-phase line voltage V _TR subtracting the phase theta _ST of the ST phase line voltage V _ST.

リレー演算処理部７７は、電流変化率算出部７４によって算出された合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sと、電圧変化率算出部７５によって算出されたＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRと、位相差算出部７６によって算出された合成電流Ｉ_R-SのＳＴ基準位相差α_STおよびＴＲ基準位相差α_TR、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RS、ＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_ST並びにＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRと基づいて、過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡、三相短絡、Ｒ−Ｓ相反相、Ｓ−Ｔ相反相、Ｔ−Ｒ相反相、スター結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線、Ｔ相断線、デルタ結線された三相電源線におけるＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線を検出すると、第１乃至第３の遮断器３₁〜３₃（図２８参照）をそれぞれ遮断するための第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を生成し、生成した第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を入出力部７９および外部機器インターフェース部８０を介して第１乃至第３の遮断器３₁〜３₃にそれぞれ出力する。 The relay calculation processing unit 77 includes a current change rate K _RS of the combined current I _RS calculated by the current change rate calculating unit 74, an RS phase line voltage V _RS calculated by the voltage change rate calculating unit 75, and an ST phase line. Voltage change rates L _RS , L _ST , L _{TR of the} inter-phase voltage V _ST and the TR phase line voltage V _TR and the ST reference phase difference α _ST and TR reference level of the combined current I _RS calculated by the phase difference calculation unit 76 Based on the phase difference α _TR , the TR reference phase difference β _{RS of} the RS phase line voltage V _RS , the RS reference phase difference β _{ST of} the ST phase line voltage V _ST , and the ST reference phase difference β _{TR of the} TR phase line voltage V _TR Overload, R-S phase short circuit, S-T phase short circuit, T-R phase short circuit, three-phase short circuit, R-S reciprocal phase, S-T reciprocal phase, TR reciprocal phase, star-connected three R phase, S phase, T phase, R phase disconnection, S phase disconnection, T phase disconnection, delta connection in phase power supply line R Aiketsusho in the power line, S Aiketsusho, T Aiketsusho, RS phase disconnection, when detecting the ST-phase disconnection and TR phase disconnection, the first to the third circuit breakers 3 ₁ to 3 ₃ (see FIG. 28 ) to the generation of the first through third trip signal T ₁ through T ₃ for blocking respectively, output the first to third trip signal T ₁ through T ₃ produced unit 79 and an external device interface unit 80 Are output to the _first to _third circuit breakers 3 _{1 to} 3 ₃ , respectively.

整定・表示部７８は、過負荷・短絡検出電流変化率値、第１および第２の過負荷・短絡検出電圧変化率値、第１および第２の過負荷・短絡検出位相差範囲、反相検出電流変化率範囲、反相検出電圧変化率範囲、反相検出位相差範囲、断線検出電流変化率範囲、第１および第２の断線検出電流変化率範囲、欠相・断線検出電圧変化率範囲、欠相検出位相差範囲並びに第１乃至第４の断線検出位相差範囲に基づいてリレー整定処理を行うとともに、整定値などを外部に表示する。   The settling / display unit 78 includes an overload / short-circuit detection current change rate value, first and second overload / short-circuit detection voltage change rate values, first and second overload / short-circuit detection phase difference ranges, anti-phase Detection current change rate range, antiphase detection voltage change rate range, antiphase detection phase difference range, disconnection detection current change rate range, first and second disconnection detection current change rate ranges, open phase / disconnection detection voltage change rate range The relay settling processing is performed based on the phase loss detection phase difference range and the first to fourth disconnection detection phase difference ranges, and the settling value and the like are displayed to the outside.

次に、以下に示す条件下におけるリレー演算処理部７７の動作について説明する。
（１）過負荷・短絡検出電流変化率＝１．１５、第１の過負荷・短絡検出電圧変化率値＝０．９６、第２の過負荷・短絡検出電圧変化率値＝０．８、第１の過負荷・短絡検出位相差範囲＝−１５０°〜−９０°、第２の過負荷・短絡検出位相差範囲＝−２０３．１°〜−９０°
（２）反相検出電流変化率範囲＝０．９〜１．１、反相検出電圧変化率範囲＝０．９〜１．１、反相検出位相差範囲＝−９０°〜−１５０°
（３）断線検出電流変化率範囲＝０．４〜０．６、第１の断線検出電流変化率範囲＝０．２〜０．４、第２の断線検出電流変化率範囲＝０．８〜０．９、欠相・断線検出電圧変化率範囲＝０．４〜０．６、欠相検出位相差範囲＝−３０°〜３０°、第１の断線検出位相差範囲＝３０°〜９０°、第２の断線検出位相差範囲＝１５０°〜２１０°、第３の断線検出位相差範囲＝９０°〜１５０°、第４の断線検出位相差範囲＝１３０°〜１５０° Next, the operation of the relay calculation processing unit 77 under the following conditions will be described.
(1) Overload / short-circuit detection current change rate = 1.15, first overload / short-circuit detection voltage change rate value = 0.96, second overload / short-circuit detection voltage change rate value = 0.8, First overload / short-circuit detection phase difference range = −150 ° to −90 °, second overload / short-circuit detection phase difference range = −203.1 ° to −90 °
(2) Anti-phase detection current change rate range = 0.9 to 1.1, anti-phase detection voltage change rate range = 0.9 to 1.1, anti-phase detection phase difference range = −90 ° to −150 °
(3) Disconnection detection current change rate range = 0.4 to 0.6, first disconnection detection current change rate range = 0.2 to 0.4, second disconnection detection current change rate range = 0.8 to 0.9, phase loss / breakage detection voltage change rate range = 0.4 to 0.6, phase loss detection phase difference range = −30 ° to 30 °, first wire breakage detection phase difference range = 30 ° to 90 ° , Second disconnection detection phase difference range = 150 ° to 210 °, third disconnection detection phase difference range = 90 ° to 150 °, fourth disconnection detection phase difference range = 130 ° to 150 °

まず、過負荷または短絡事故発生時のリレー演算処理部７７の動作について、図３５に示すフローチャートを参照して説明する。
リレー演算処理部７７は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）以上であるか否かを調べ（ステップＳ１２１）、電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値以上であると、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RSが第１の過負荷・短絡検出電圧変化率値（＝０．９６）以下であるか否かを調べる（ステップＳ１２２）。
リレー演算処理部７７は、電圧変化率Ｌ_RSが第１の過負荷・短絡検出電圧変化率値以下でないと、「過負荷が発生した」と判定する（ステップＳ１２９ａ）。 First, the operation of the relay calculation processing unit 77 when an overload or short circuit accident occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 77, the composite current I current change rate K _RS overload or short circuit detecting current change rate value of _RS (= 1.15) examined in whether more (step S121), the current change rate K _{If RS} is equal to or greater than the overload / short-circuit detection current change rate value, the voltage change rate L _RS of the RS phase line voltage V _RS is equal to or less than the first overload / short-circuit detection voltage change rate value (= 0.96). It is checked whether or not there is (step S122).
If the voltage change rate L _RS is not less than or equal to the first overload / short-circuit detection voltage change rate value, the relay calculation processing unit 77 determines that “overload has occurred” (step S129a).

一方、ステップＳ１２２において電圧変化率Ｌ_RSが第１の過負荷・短絡検出電圧変化率値以下であると、リレー演算処理部７７は、電圧変化率Ｌ_RSが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べ（ステップＳ１２３）、電圧変化率Ｌ_RSが第２の過負荷・短絡検出電圧変化率値以下であると、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べる（ステップＳ１２４）。
リレー演算処理部７７は、電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値以下でないと、「Ｒ−Ｓ相短絡が発生した」と判定し（ステップＳ１２９ｂ）、一方、電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値以下であると、「三相短絡が発生した」と判定する（ステップＳ１２９ｅ） On the other hand, if the voltage change rate L _RS is equal to or less than the first overload / short circuit detection voltage change rate value in step S122, the relay calculation processing unit 77 determines that the voltage change rate L _RS is the second overload / short circuit detection voltage. It is checked whether or not the change rate value (= 0.8) or less (step S123). If the voltage change rate L _RS is less than or equal to the second overload / short-circuit detection voltage change rate value, the ST phase line voltage voltage change rate L _ST second overload or short circuit detecting voltage change rate value V _ST (= 0.8) checks less if it (step S124).
Relay processing section 77, when the voltage change rate L _ST not less than the second overload or short circuit detecting voltage change rate value, determines that the "R-S phase short circuit occurs" (step S129b), whereas, the voltage When the rate of change L _ST is equal to or less than the second overload or short circuit detecting voltage change rate value, it determines that the "three-phase short circuit occurs" (step S129e)

ステップＳ１２１において電流変化率Ｋ_R-Sが過負荷・短絡検出電流変化率値（＝１．１５）未満であるかステップＳ１２３において電圧変化率Ｌ_RSが第２の過負荷・短絡検出電圧変化率値よりも大きいと、リレー演算処理部７７は、電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値（＝０．８）以下であるか否かを調べ（ステップＳ１２５）、電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値以下であると、合成電流Ｉ_R-SのＳＴ基準位相差α_STが第１の過負荷・短絡検出位相差範囲（＝−１５０°〜−９０°）内の値であるか否かを調べる（ステップＳ１２６）。
リレー演算処理部７７は、ＳＴ基準位相差α_STが第１の過負荷・短絡検出位相差範囲内の値であると、「Ｓ−Ｔ相短絡が発生した」と判定する（ステップＳ１２９ｃ）。 Current change rate K _RS overload or short circuit detected current change rate value at step S121 (= 1.15) the rate of voltage change in a is either step S123 less than L _RS is higher than the second overload or short circuit detecting voltage change rate value When is large, the relay processing unit 77, the voltage change rate L _ST second overload or short circuit detecting voltage change rate value (= 0.8) examines if the either less (step S125), the voltage change When the rate L _ST is equal to or less than the second overload / short-circuit detection voltage change rate value, the ST reference phase difference α _ST of the combined current I _RS is equal to the first overload / short-circuit detection phase difference range (= −150 ° to It is checked whether the value is within -90 °) (step S126).
When the ST reference phase difference α _ST is a value within the first overload / short-circuit detection phase difference range, the relay calculation processing unit 77 determines that “ST phase short-circuit has occurred” (step S129c).

ステップＳ１２５においてＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが第２の過負荷・短絡検出電圧変化率値よりも大きいと、リレー演算処理部７７は、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下であるか否かを調べ（ステップＳ１２７）、電圧変化率Ｌ_TRが第２の過負荷・短絡検出電圧変化率値以下であると、合成電流Ｉ_R-SのＴＲ基準位相差α_TRが第２の過負荷・短絡検出位相差範囲（＝−２０３．１°〜−９０°）内の値であるか否かを調べる（ステップＳ１２８）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第２の過負荷・短絡検出位相差範囲内の値であると、「Ｔ−Ｒ相短絡が発生した」と判定する（ステップＳ１２９ｄ）。 When the voltage change rate L _ST of the ST phase line voltage V _ST is larger than the second overload / short circuit detection voltage change rate value in step S125, the relay calculation processing unit 77 determines the voltage of the TR phase line voltage V _TR . It is checked whether or not the rate of change L _TR is less than or equal to the second overload / short circuit detection voltage change rate value (step S127), and the voltage change rate L _TR is less than or equal to the second overload / short circuit detection voltage change rate value. If there is, it is checked whether or not the TR reference phase difference α _TR of the combined current I _RS is a value within the second overload / short-circuit detection phase difference range (= −203.1 ° to −90 °) (step) S128).
When the TR reference phase difference α _TR is a value within the second overload / short circuit detection phase difference range, the relay calculation processing unit 77 determines that “TR phase short circuit has occurred” (step S129d).

リレー演算処理部７７は、以上のようにして過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡または三相短絡の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ１３０）。 When the relay calculation processing unit 77 detects the occurrence of overload, RS phase short circuit, ST phase short circuit, TR phase short circuit, or three-phase short circuit as described above, the first to third trip signals are detected. T _{1 to} T ₃ are output (step S130).

次に、反相発生時のリレー演算処理部７７の動作について、図３６に示すフローチャートを参照して説明する。
リレー演算処理部７７は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが反相検出電流変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ１３１）、電流変化率Ｋ_R-Sが反相検出電流変化率範囲内の値であると、ＲＳ相線間電圧Ｖ_RS、ＳＴ相線間電圧Ｖ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRがすべて反相検出電圧変化率範囲（＝０．９〜１．１）内の値であるか否かを調べ（ステップＳ１３２）、電圧変化率Ｌ_RS，Ｌ_ST，Ｌ_TRがすべて反相検出電圧変化率範囲内の値であると、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSが反相検出位相差範囲（＝−９０°〜−１５０°）内の値であるか否かを調べる（ステップＳ１３４）。
リレー演算処理部７７は、ＴＲ基準位相差β_RSが反相検出位相差範囲内の値であると、「反相が発生した」と判定して（ステップＳ１３４）、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ１３５）。 Next, the operation of the relay calculation processing unit 77 when a reverse phase occurs will be described with reference to the flowchart shown in FIG.
Relay processing section 77 checks whether the combined current I current change rate K _RS of _RS is a value within the anti-phase detected current change rate range (= 0.9 to 1.1) (step S131), If the current change rate K _RS is a value within the antiphase detection current change rate range, the voltage change rate L _{RS of} the RS phase line voltage V _RS , the ST phase line voltage V _ST, and the TR phase line voltage V _TR , It is checked whether or not L _ST and L _TR are all values within the antiphase detection voltage change rate range (= 0.9 to 1.1) (step S132), and the voltage change rates L _RS , L _ST and L _{TR are determined.} Are all within the anti-phase detection voltage change rate range, the TR reference phase difference β _{RS of} the RS phase line voltage V _RS is within the anti-phase detection phase difference range (= −90 ° to −150 °). Is checked (step S134).
When the TR reference phase difference β _RS is a value within the anti-phase detection phase difference range, the relay calculation processing unit 77 determines that “an anti-phase has occurred” (step S134), and the first to third trips Signals T _{1 to} T ₃ are output (step S135).

次に、スター結線された三相電源線における欠相または断線発生時のリレー演算処理部７７の動作について、図３７および図３８に示すフローチャートを参照して説明する。
リレー演算処理部７７は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１４１）、電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲内の値であると、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１４２）、電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値でないと、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１４３）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値でないと、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１４４）。
リレー演算処理部７７は、ＴＲ基準位相差β_RSが欠相検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ１５３ａ）。 Next, the operation of the relay calculation processing unit 77 when a phase loss or disconnection occurs in the star-connected three-phase power supply line will be described with reference to the flowcharts shown in FIGS.
The relay calculation processing unit 77 checks whether or not the voltage change rate L _RS of the RS phase line voltage V _RS is a value within the phase loss / breakage detection voltage change rate range (= 0.4 to 0.6). (step S141), when the voltage change rate L _RS is a value of phase loss-disconnection detecting voltage change rate range, the voltage change rate L _ST is open phase-disconnection detecting voltage change rate range of the voltage V _ST between the ST phase line (= 0.4-0.6) examines if the value is either inside (step S142), when the voltage change rate L _ST not a value of the open phase-disconnection detecting voltage change rate range, between TR phase line the voltage change rate L _TR of the voltage V _TR checked whether the value of the open phase-disconnection detecting voltage change rate range (= 0.4 to 0.6) in (step S143), the voltage change rate L _TR If not a value of the open phase-disconnection detecting voltage change rate range, TR reference phase difference beta _RS is open phase detection phase difference range of the voltage V _RS between RS phase line (= -30 ° ~ - It is checked whether the value is within 30 ° (step S144).
When the TR reference phase difference β _RS is a value within the phase loss detection phase difference range, the relay calculation processing unit 77 determines that “R phase phase loss has occurred” (step S153a).

ステップＳ１４２において電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値であると、リレー演算処理部７７は、ＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１４５）。
リレー演算処理部７７は、ＲＳ基準位相差β_STが欠相検出位相差範囲内の値であると、「Ｓ相欠相が発生した」と判定する（ステップＳ１５３ｂ）。 If voltage change rate _LST is a value within the phase loss / disconnection detection voltage change rate range in step S142, relay operation processing unit 77 detects that RS reference phase difference _βST of ST phase line voltage _VST is a phase loss detection. It is checked whether or not the value is within the phase difference range (= −30 ° to −30 °) (step S145).
Relay processing section 77 determines, when the RS reference phase difference beta _ST is a value phase loss detection phase range, the "S-phase phase loss has occurred" (step S153b).

ステップＳ１４１において電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部７７は、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１４６）、電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１４７）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１４８）。
リレー演算処理部７７は、ＳＴ基準位相差β_TRが欠相検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ１５３ｃ）。 When the voltage change rate L _RS not a value of the open phase-disconnection detecting voltage change rate range in step S141, the relay processing unit 77, the voltage change rate L _ST of the voltage V _ST between the ST phase line open phase-break detection checked whether the value of the voltage change rate range (= 0.4 to 0.6) in (step S146), when the voltage change rate L _ST is a value of phase loss-disconnection detecting voltage change rate range Then, it is checked whether or not the voltage change rate L _{TR of} the TR phase line-to-line voltage V _TR is a value within the phase loss / disconnection detection voltage change rate range (= 0.4 to 0.6) (step S147). When the rate of change L _TR is a value open phase-disconnection detecting voltage change rate range, ST reference phase difference beta _TR is open phase detection phase difference range of the voltage V _TR - TR phase line (= -30 ° ~-30 It is checked whether the value is within (°) (step S148).
If the ST reference phase difference β _TR is a value within the phase loss detection phase difference range, the relay calculation processing unit 77 determines that “T phase phase loss has occurred” (step S153c).

ステップＳ１４６において電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部７７は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが断線検出電流変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（図３８のステップＳ１４９）、電流変化率Ｋ_R-Sが断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-SのＴＲ基準位相差α_TRが第１の断線検出位相差範囲（３０°〜９０°）内の値であるか否かを調べる（ステップＳ１５０）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第１の断線検出位相差範囲内の値であると、「Ｒ相断線が発生した」と判定する（ステップＳ１５３ｄ）。 When the voltage change rate L _ST in step S146 is not a value within the range open phase-disconnection detecting voltage change rate, the relay processing unit 77, the composite current I current change rate K _RS disconnection detection current change rate range of _RS (= 0.4 to 0.6) is checked (step S149 in FIG. 38), and if the current change rate K _RS is a value within the disconnection detection current change rate range, the composite current I _RS is It is checked whether or not the TR reference phase difference α _TR is a value within the first disconnection detection phase difference range (30 ° to 90 °) (step S150).
When the TR reference phase difference α _TR is a value within the first disconnection detection phase difference range, the relay calculation processing unit 77 determines that “R-phase disconnection has occurred” (step S153d).

一方、ステップＳ１５０においてＴＲ基準位相差α_TRが第１の断線検出位相差範囲内の値でないと、リレー演算処理部７７は、合成電流Ｉ_R-SのＴＲ基準位相差α_TRが第２の断線検出位相差範囲（１５０°〜２１０°）内の値であるか否かを調べる（ステップＳ１５１）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第２の断線検出位相差範囲内の値であると、「Ｓ相断線が発生した」と判定する（ステップＳ１５３ｅ）。 On the other hand, if the TR reference phase difference α _TR is not within the first disconnection detection phase difference range in step S150, the relay calculation processing unit 77 detects that the TR reference phase difference α _TR of the combined current I _RS is the second disconnection detection. It is checked whether the value is within the phase difference range (150 ° to 210 °) (step S151).
The relay calculation processing unit 77 determines that “S phase disconnection has occurred” when the TR reference phase difference α _TR is a value within the second disconnection detection phase difference range (step S153e).

ステップＳ１４９において電流変化率Ｋ_R-Sが断線検出電流変化率範囲内の値でないと、リレー演算処理部７７は、合成電流Ｉ_R-SのＴＲ基準位相差α_TRが第３の断線検出位相差範囲（＝９０°〜１５０°）内の値であるか否かを調べる（ステップＳ１５４）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第３の断線検出位相差範囲内の値であると、「Ｔ相断線が発生した」と判定する（ステップＳ１５３ｆ）。 If the current change rate K _RS is not a value within the disconnection detection current change rate range in step S149, the relay calculation processing unit 77 determines that the TR reference phase difference α _TR of the combined current I _RS is the third disconnection detection phase difference range (= Whether the value is within the range of 90 ° to 150 ° is checked (step S154).
When TR reference phase difference α _TR is a value within the third disconnection detection phase difference range, relay calculation processing unit 77 determines that “T-phase disconnection has occurred” (step S153f).

リレー演算処理部７７は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線またはＴ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ１５４）。 When the relay calculation processing unit 77 detects the occurrence of the R-phase, S-phase, T-phase, R-phase, S-phase, or T-phase break as described above, the first to third Trip signals T _{1 to} T ₃ are output (step S154).

次に、デルタ結線された三相電源線における欠相または断線発生時のリレー演算処理部７７の動作について、図３９および図４０に示すフローチャートを参照して説明する。
リレー演算処理部７７は、ＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１６１）、電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲内の値であると、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１５２）、電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値でないと、Ｒ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１６３）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値でないと、ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差β_RSが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１６４）。
リレー演算処理部７７は、ＴＲ基準位相差β_RSが欠相検出位相差範囲内の値であると、「Ｒ相欠相が発生した」と判定する（ステップＳ１７３ａ）。 Next, the operation of the relay computation processing unit 77 when a phase loss or disconnection occurs in the delta-connected three-phase power supply line will be described with reference to the flowcharts shown in FIGS. 39 and 40.
The relay calculation processing unit 77 checks whether or not the voltage change rate L _RS of the RS phase line voltage V _RS is a value within the phase loss / breakage detection voltage change rate range (= 0.4 to 0.6). (step S161), when the voltage change rate L _RS is a value of phase loss-disconnection detecting voltage change rate range, the voltage change rate L _ST is open phase-disconnection detecting voltage change rate range of the voltage V _ST between the ST phase line (= 0.4-0.6) examines if the value is either inside (step S152), when the voltage change rate L _ST not a value of the open phase-disconnection detecting voltage change rate range, between the R-phase line the voltage change rate L _TR of the voltage V _TR checked whether the value of the open phase-disconnection detecting voltage change rate range (= 0.4 to 0.6) in (step S163), the voltage change rate L _TR If the value is not within the range of the phase loss / disconnection detection voltage change rate range, the TR reference phase difference β _{RS of} the RS phase line voltage V _RS is equal to the phase loss detection phase difference range (= −30 ° to −3). It is checked whether the value is within 0 ° (step S164).
When the TR reference phase difference β _RS is a value within the phase loss detection phase difference range, the relay calculation processing unit 77 determines that “R phase phase loss has occurred” (step S173a).

ステップＳ１６２において電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値であると、リレー演算処理部７７は、ＳＴ相線間電圧Ｖ_STのＲＳ基準位相差β_STが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１６５）。
リレー演算処理部７７は、ＲＳ基準位相差β_STが欠相検出位相差範囲内の値であると、「Ｓ相欠相が発生した」と判定する（ステップＳ１７３ｂ）。 If voltage change rate _LST is a value within the phase loss / breakage detection voltage change rate range in step S162, relay operation processing unit 77 detects that RS reference phase difference _βST of ST phase line voltage _VST is a phase loss detection. It is checked whether or not the value is within the phase difference range (= −30 ° to −30 °) (step S165).
Relay processing section 77 determines, when the RS reference phase difference beta _ST is a value phase loss detection phase range, the "S-phase phase loss has occurred" (step S173b).

ステップＳ１６１において電圧変化率Ｌ_RSが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部７７は、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１６６）、電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲（＝０．４〜０．６）内の値であるか否かを調べ（ステップＳ１６７）、電圧変化率Ｌ_TRが欠相・断線検出電圧変化率範囲内の値であると、ＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差β_TRが欠相検出位相差範囲（＝−３０°〜−３０°）内の値であるか否かを調べる（ステップＳ１６８）。
リレー演算処理部７７は、ＳＴ基準位相差β_TRが欠相検出位相差範囲内の値であると、「Ｔ相欠相が発生した」と判定する（ステップＳ１７３ｃ）。 When the voltage change rate L _RS not a value of the open phase-disconnection detecting voltage change rate range in step S161, the relay processing unit 77, the voltage change rate L _ST of the voltage V _ST between the ST phase line open phase-break detection checked whether the value of the voltage change rate range (= 0.4 to 0.6) in (step S166), when the voltage change rate L _ST is a value of phase loss-disconnection detecting voltage change rate range Then, it is checked whether or not the voltage change rate L _{TR of} the TR phase line-to-line voltage V _TR is a value within the phase loss / disconnection detection voltage change rate range (= 0.4 to 0.6) (step S167), and the voltage When the rate of change L _TR is a value open phase-disconnection detecting voltage change rate range, ST reference phase difference beta _TR is open phase detection phase difference range of the voltage V _TR - TR phase line (= -30 ° ~-30 It is checked whether the value is within (°) (step S168).
When the ST reference phase difference β _TR is a value within the phase loss detection phase difference range, the relay calculation processing unit 77 determines that “T phase phase loss has occurred” (step S173c).

ステップＳ１６６において電圧変化率Ｌ_STが欠相・断線検出電圧変化率範囲内の値でないと、リレー演算処理部７７は、合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sが第１の断線検出電流変化率範囲（＝０．２〜０．４）内の値であるか否かを調べる（図４０のステップＳ１６９）。
リレー演算処理部７７は、電流変化率Ｋ_R-Sが断線検出電流変化率範囲内の値であると、「ＲＳ相断線が発生した」と判定する（ステップＳ１７３ｄ）。 When the voltage change rate L _ST not a value of the open phase-disconnection detecting voltage change rate range in step S166, the relay processing unit 77, the composite current I current change rate K _RS is the first disconnection detecting the current change rate of the _RS It is checked whether or not the value is within the range (= 0.2 to 0.4) (step S169 in FIG. 40).
Relay processing section 77 determines the current rate of change K _RS when a value within the disconnection detection current change rate range, and "RS phase disconnection has occurred" (step S173d).

一方、ステップＳ１６９において電流変化率Ｋ_R-Sが断線検出電流変化率範囲内の値でないと、リレー演算処理部７７は、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲（＝０．８〜０．９）内の値であるか否かを調べ（ステップＳ１７０）、電流変化率Ｋ_R-Sが第２の断線検出電流変化率範囲内の値であると、合成電流Ｉ_R-SのＴＲ基準位相差α_TRが第４の断線検出位相差範囲（＝１３０°〜１５０°）内の値であるか否かを調べる（ステップＳ１７１）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第４の断線検出位相差範囲内の値であると、「ＳＴ相断線が発生した」と判定する（ステップＳ１７３ｅ）。 On the other hand, if the current change rate K _RS is not a value within the disconnection detection current change rate range in step S169, the relay calculation processing unit 77 determines that the current change rate K _RS is equal to the second disconnection detection current change rate range (= 0.8). To 0.9) (step S170), and if the current change rate K _RS is a value within the second disconnection detection current change rate range, the TR reference position of the combined current I _RS It is checked whether or not the phase difference α _TR is a value within the fourth disconnection detection phase difference range (= 130 ° to 150 °) (step S171).
When the TR reference phase difference α _TR is a value within the fourth disconnection detection phase difference range, the relay calculation processing unit 77 determines that “ST phase disconnection has occurred” (step S173e).

一方、ステップＳ１７１においてＴＲ基準位相差α_TRが第４の断線検出位相差範囲内の値でないと、リレー演算処理部７７は、ＴＲ基準位相差α_TRが第４の断線検出位相差範囲（＝９０°〜１１０°）内の値であるか否かを調べる（ステップＳ１７２）。
リレー演算処理部７７は、ＴＲ基準位相差α_TRが第４の断線検出位相差範囲内の値であると、「ＴＲ相断線が発生した」と判定する（ステップＳ１７３ｆ）。 On the other hand, if the TR reference phase difference α _TR is not a value within the fourth disconnection detection phase difference range in step S171, the relay calculation processing unit 77 determines that the TR reference phase difference α _TR is equal to the fourth disconnection detection phase difference range (= It is checked whether the value is within the range of 90 ° to 110 ° (step S172).
When the TR reference phase difference α _TR is a value within the fourth disconnection detection phase difference range, the relay calculation processing unit 77 determines that “TR phase disconnection has occurred” (step S173f).

リレー演算処理部７７は、以上のようにしてＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線またはＴ相断線の発生を検出すると、第１乃至第３のトリップ信号Ｔ₁〜Ｔ₃を出力する（ステップＳ１７４）。 When the relay calculation processing unit 77 detects the occurrence of the R-phase, S-phase, T-phase, R-phase, S-phase, or T-phase break as described above, the first to third Trip signals T _{1 to} T ₃ are output (step S174).

以上の説明ではＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの定格電流値を基準として合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sを求めたが、負荷の変動が小さい場合などでは１サイクル前のＲ相、Ｓ相およびＴ相電流Ｉ_R，Ｉ_S，Ｉ_Tの値を基準として合成電流Ｉ_R-Sの電流変化率Ｋ_R-Sを求めてもよい。 R phase in the above description, S-phase and T-phase currents I _R, I _S, has been determined current change rate K _RS synthetic current I _RS, based on the rated current value of I _T, if the variation in load is small such as Then, the current change rate K _RS of the combined current I _RS may be obtained based on the values of the R-phase, S-phase, and T-phase currents I _R , I _S , I _T one cycle before.

また、Ｒ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの定格電圧値を基準としてＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STおよびＴＲ相線間電圧Ｖ_TRの電圧変化率Ｌ_TRを求めたが、１サイクル前のＲ相、Ｓ相およびＴ相電圧Ｖ_R，Ｖ_S，Ｖ_Tの値を基準としてＲＳ相線間電圧Ｖ_RSの電圧変化率Ｌ_RS、ＳＴ相線間電圧Ｖ_STの電圧変化率Ｌ_STおよびＴＲ相線間電圧Ｖ_TRを求めてもよい。 Further, the voltage change rate L _RS of the RS phase line voltage V _{RS and} the voltage change of the ST phase line voltage V _{ST on} the basis of the rated voltage values of the R phase, S phase, and T phase voltages V _R , V _S , V _T The rate L _ST and the voltage change rate L _TR of the TR phase line voltage V _TR were obtained, but the RS phase based on the values of the R phase, S phase, and T phase voltages V _R , V _S , V _T one cycle before voltage change rate L _RS line voltage V _RS, may be obtained a voltage V _TR voltage change rate of the voltage V _ST between the ST phase line L _ST and TR phase line.

さらに、三相電源線のＲ相およびＳ相に設けたクロス貫通変流器１１，４１，６１から合成電流Ｉ_R-Sを３Ｅリレー２０，５０，７０に入力するとともに三相電源線に設けた計器用変成器１２，４２，６２からＲＳ相線間電圧Ｖ_RS，ＳＴ相線間電圧Ｖ_ST，ＴＲ相線間電圧Ｖ_TRを３Ｅリレー２０，５０，７０に入力したが、低電圧の三相電源線の場合には変流比が１：１のクロス貫通変流器および変成比が１：１の計器用変成器を３Ｅリレー２０，５０，７０に内蔵させてもよい。 Further, the combined current I _RS is input to the 3E relays 20, 50, 70 from the cross-through current transformers 11, 41, 61 provided in the R phase and S phase of the three-phase power supply line, and the meter provided in the three-phase power supply line RS phase line voltage V _RS , ST phase line voltage V _ST , and TR phase line voltage V _TR are input to 3E relays 20, 50, and 70 from transformers 12, 42, and 62. In the case of a power supply line, a cross-through current transformer with a current transformation ratio of 1: 1 and an instrument transformer with a transformation ratio of 1: 1 may be incorporated in the 3E relays 20, 50, and 70.

本発明の第１の実施例による保護継電システムの構成を示す図である。It is a figure which shows the structure of the protection relay system by 1st Example of this invention. 図１に示したクロス貫通変流器１１および計器用変成器１２から３Ｅリレー２０に正常時に入力される合成電流Ｉ_(R-S)0およびＴＲ相線間電圧Ｖ_TR0について説明するための図である。FIG. 3 is a diagram for explaining a combined current I _{(RS) 0} and a TR phase line voltage V _TR0 that are normally input to the 3E relay 20 from the cross-through current transformer 11 and the instrument transformer 12 shown in FIG. . 図１に示した３Ｅリレー２０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 20 shown in FIG. 1, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図１に示した３Ｅリレー２０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 20 shown in FIG. 1, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図１に示した３Ｅリレー２０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 20 shown in FIG. 1, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図１に示した３Ｅリレー２０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the RS reciprocal phase, ST phase reciprocal phase, and TR reciprocal phase in the 3E relay 20 shown in FIG. 図１に示した３Ｅリレー２０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the RS reciprocal phase, ST phase reciprocal phase, and TR reciprocal phase in the 3E relay 20 shown in FIG. 図１に示した３Ｅリレー２０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について説明するための図である。A method of detecting the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase breaks of the star-connected three-phase power supply line in the 3E relay 20 shown in FIG. FIG. 図１に示した３Ｅリレー２０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について説明するための図である。A method of detecting the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase breaks of the star-connected three-phase power supply line in the 3E relay 20 shown in FIG. FIG. 図１に示した３Ｅリレー２０におけるデルタ結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、ＲＳ相断線、ＳＴ相断線およびＴＲ相断線の検出方法について説明するための図である。A method for detecting the R-phase, S-phase, T-phase, RS-phase, ST-phase, and TR-phase disconnections of the three-phase power supply line connected in the delta connection shown in FIG. 1 will be described. FIG. 図１に示した３Ｅリレー２０の構成を示すブロック図である。It is a block diagram which shows the structure of 3E relay 20 shown in FIG. 過負荷時または短絡事故発生時の図１１に示したリレー演算処理部２８の動作について説明するためのフローチャートである。12 is a flowchart for explaining an operation of the relay calculation processing unit 28 shown in FIG. 11 when an overload or a short circuit accident occurs. 反相発生時の図１１に示したリレー演算処理部２８の動作について説明するためのフローチャートである。12 is a flowchart for explaining the operation of the relay calculation processing unit 28 shown in FIG. 11 when a reverse phase occurs. スター結線された三相電源線における欠相または断線発生時の図１１に示したリレー演算処理部２８の動作について説明するためのフローチャートである。12 is a flowchart for explaining the operation of the relay calculation processing unit 28 shown in FIG. 11 when a phase loss or disconnection occurs in a star-connected three-phase power supply line. デルタ結線された三相電源線における欠相または断線発生時の図１１に示したリレー演算処理部２８の動作について説明するためのフローチャートである。12 is a flowchart for explaining the operation of relay arithmetic processing unit 28 shown in FIG. 11 when a phase loss or disconnection occurs in a delta-connected three-phase power supply line. デルタ結線された三相電源線における欠相または断線発生時の図１１に示したリレー演算処理部２８の動作について説明するためのフローチャートである。12 is a flowchart for explaining the operation of relay arithmetic processing unit 28 shown in FIG. 11 when a phase loss or disconnection occurs in a delta-connected three-phase power supply line. 本発明の第２の実施例による保護継電システムの構成を示す図である。It is a figure which shows the structure of the protection relay system by the 2nd Example of this invention. 図１７に示した３Ｅリレー５０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 50 shown in FIG. 17, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図１７に示した３Ｅリレー５０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について説明するための図である。It is a figure for demonstrating the detection method of RS reciprocal phase, ST reciprocal phase, and TR reciprocal phase in the 3E relay 50 shown in FIG. 図１７に示した３Ｅリレー５０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について説明するための図である。A method of detecting the R-phase, S-phase, T-phase, R-phase, S-phase, and T-phase breaks of the star-connected three-phase power supply line in the 3E relay 50 shown in FIG. 17 will be described. FIG. 図１７に示した３Ｅリレー５０の構成を示すブロック図である。It is a block diagram which shows the structure of 3E relay 50 shown in FIG. 過負荷または短絡事故発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 58 shown in FIG. 21 at the time of an overload or a short circuit accident. 反相発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay calculation process part 58 shown in FIG. 21 at the time of a reverse phase generation | occurrence | production. スター結線された三相電源線における欠相または断線発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 58 shown in FIG. 21 at the time of the phase loss in the three-phase power source line connected by star connection, or disconnection. スター結線された三相電源線における欠相または断線発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 58 shown in FIG. 21 at the time of the phase loss in the three-phase power source line connected by star connection, or disconnection. デルタ結線された三相電源線における欠相または断線発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 58 shown in FIG. デルタ結線された三相電源線における欠相または断線発生時の図２１に示したリレー演算処理部５８の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 58 shown in FIG. 21 at the time of the phase loss or disconnection generate | occur | producing in the delta-connected three-phase power supply line. 本発明の第３の実施例による保護継電システムの構成を示す図である。It is a figure which shows the structure of the protection relay system by the 3rd Example of this invention. 図２８に示したクロス貫通変流器６１および計器用変成器６２から３Ｅリレー７０に正常時に入力される合成電流Ｉ_(R-S)0、ＲＳ相線間電圧Ｖ_RS0、ＳＴ相線間電圧Ｖ_ST0およびＴＲ相線間電圧Ｖ_TR0について説明するための図である。The combined current I _{(RS) 0} , RS phase line voltage V _RS0 , ST phase line voltage V _ST0 that is normally input to the 3E relay 70 from the cross-through current transformer 61 and the instrument transformer 62 shown in FIG. FIG. 6 is a diagram for explaining a TR phase line voltage V _TR0 . 図２８に示した３Ｅリレー７０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 70 shown in FIG. 28, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図２８に示した３Ｅリレー７０における過負荷、Ｒ−Ｓ相短絡、Ｓ−Ｔ相短絡、Ｔ−Ｒ相短絡および三相短絡の検出方法について説明するための図である。It is a figure for demonstrating the detection method of the overload in the 3E relay 70 shown in FIG. 28, RS phase short circuit, ST phase short circuit, TR phase short circuit, and three phase short circuit. 図２８に示した３Ｅリレー７０におけるＲ−Ｓ相反相、Ｓ−Ｔ相反相およびＴ−Ｒ相反相の検出方法について説明するための図である。It is a figure for demonstrating the detection method of RS reciprocal phase, ST reciprocal phase, and TR reciprocal phase in 3E relay 70 shown in FIG. 図２８に示した３Ｅリレー７０におけるスター結線された三相電源線のＲ相欠相、Ｓ相欠相、Ｔ相欠相、Ｒ相断線、Ｓ相断線およびＴ相断線の検出方法について説明するための図である。A method of detecting the R-phase, S-phase, T-phase, R-phase, R-phase, S-phase, and T-phase disconnection of the star-connected three-phase power supply line in the 3E relay 70 shown in FIG. FIG. 図２８に示した３Ｅリレー７０の構成を示すブロック図である。It is a block diagram which shows the structure of 3E relay 70 shown in FIG. 過負荷または短絡事故発生時の図３４に示したリレー演算処理部７７の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 77 shown in FIG. 34 at the time of an overload or a short circuit accident. 反相発生時の図３４に示したリレー演算処理部７７の動作について説明するためのフローチャートである。It is a flowchart for demonstrating operation | movement of the relay arithmetic processing part 77 shown in FIG. 34 at the time of a reverse phase generation | occurrence | production. スター結線された三相電源線における欠相または断線発生時の図３４に示したリレー演算処理部７７の動作について説明するためのフローチャートである。FIG. 35 is a flowchart for explaining the operation of relay operation processing unit 77 shown in FIG. 34 when a phase loss or disconnection occurs in a star-connected three-phase power supply line. スター結線された三相電源線における欠相または断線発生時の図２８に示したリレー演算処理部７７の動作について説明するためのフローチャートである。FIG. 29 is a flowchart for describing an operation of relay arithmetic processing unit 77 shown in FIG. 28 when a phase loss or disconnection occurs in a star-connected three-phase power supply line. デルタ結線された三相電源線における欠相または断線発生時の図２８に示したリレー演算処理部７７の動作について説明するためのフローチャートである。FIG. 29 is a flowchart for explaining the operation of relay operation processing unit 77 shown in FIG. 28 when a phase loss or disconnection occurs in a delta-connected three-phase power supply line. デルタ結線された三相電源線における欠相または断線発生時の図２８に示したリレー演算処理部７７の動作について説明するためのフローチャートである。FIG. 29 is a flowchart for explaining the operation of relay operation processing unit 77 shown in FIG. 28 when a phase loss or disconnection occurs in a delta-connected three-phase power supply line. 従来の三相誘導電動機用３Ｅリレー１１０について説明するための図である。It is a figure for demonstrating the conventional 3E relay 110 for three-phase induction motors.

符号の説明Explanation of symbols

１₁〜１₃ 第１乃至第３の変流器
２，１２，４２，６２ 計器用変成器
３₁〜３₃ 第１乃至第３の遮断器
１１，４１，６１ クロス貫通変流器
２０，５０，７０，１１０ ３Ｅリレー
２１，５１，７１ 入力変換器
２２，５２，７２ アナログ入力部
２３，５３，７３ メモリ
２４，５４，７４ 電流変化率算出部
２５，５５，７５ 電圧変化率算出部
２６，５６ 位相変化角算出部
２７，５７，７６ 位相差算出部
２８，５８，７７ リレー演算処理部
２９，５９，７８ 整定・表示部
３０，６０，７９ 入出部
３１，６１，８０ 外部機器Ｉ／Ｆ部
Ｉ_R，Ｉ_S，Ｉ_T Ｒ相、Ｓ相およびＴ相電流
Ｉ_R0，Ｉ_S0，Ｉ_T0 正常時のＲ相、Ｓ相およびＴ相電流
Ｉ_R-S 合成電流
Ｉ_(R-S)0 正常時の合成電流
Ｉ_FR，Ｉ_FS，Ｉ_FT Ｒ相、Ｓ相およびＴ相事故電流
Ｖ_R，Ｖ_S，Ｖ_T Ｒ相、Ｓ相およびＴ相電圧
Ｖ_R0，Ｖ_S0，Ｖ_T0 正常時のＲ相、Ｓ相およびＴ相電圧
Ｖ_RS，Ｖ_ST，Ｖ_TR ＲＳ相、ＳＴ相およびＴＲ相線間電圧
Ｖ_RS0，Ｖ_ST0，Ｖ_TR0 正常時のＲＳ相、ＳＴ相およびＴＲ相線間電圧
Ｔ₁〜Ｔ₃ 第１乃至第３のトリップ信号
θ_T，θ_RS，θ_ST，θ_TR，θ_R-S 位相
θ_R0，θ_T0，θ_RS0，θ_ST0，θ_TR0，θ_{(R-S) 0} 正常時の位相
Δθ_TR，Δθ_T 位相変化角
θ インピーダンス角
Ｋ_R-S 電流変化率
Ｌ_T，Ｌ_RS，Ｌ_ST，Ｌ_TR 電圧変化率
α，β 位相差
α₀，β₀ 正常時の位相差
α_ST 合成電流Ｉ_R-SのＳＴ基準位相差
α_TR 合成電流Ｉ_R-SのＴＲ基準位相差
β_RS ＲＳ相線間電圧Ｖ_RSのＴＲ基準位相差
β_RS0 正常時のＲＳ相線間電圧Ｖ_RS0のＴＲ基準位相差
β_ST ＳＴ相線間電圧Ｖ_STのＲＳ基準位相差
β_ST0 正常時のＳＴ相線間電圧Ｖ_ST0のＲＳ基準位相差
β_TR ＴＲ相線間電圧Ｖ_TRのＳＴ基準位相差
β_TR0 正常時のＴＲ相線間電圧Ｖ_TR0のＳＴ基準位相差
Ｓ１０〜Ｓ１８，Ｓ１９ａ〜ｓ１９ｅ，Ｓ２０〜Ｓ２５，Ｓ３１〜Ｓ３８，Ｓ３９ａ〜Ｓ３９ｅ，Ｓ４０〜Ｓ５０，Ｓ５１ａ〜Ｓ５１ｆ，Ｓ５２，Ｓ６０〜Ｓ６８，Ｓ６９ａ〜Ｓ６９ｅ，Ｓ７０〜Ｓ７６，Ｓ８１〜Ｓ９６，Ｓ９２ａ〜Ｓ９２ｆ，Ｓ９３，Ｓ１０１〜Ｓ１１２，Ｓ１１３ａ〜Ｓ１１３ｆ，Ｓ１１４，Ｓ１２１〜Ｓ１２８，Ｓ１２９ａ〜ｓ１２９ｅ，Ｓ１３０〜Ｓ１３５，Ｓ１４１〜Ｓ１５２，Ｓ１５３ａ〜Ｓ１５３ｆ，Ｓ１５４，Ｓ１６１〜Ｓ１７２，Ｓ１７３ａ〜Ｓ１７３ｆ，Ｓ１７４ ステップ 1 ₁ to 1 _{3 1st} to _3rd current transformers 2, 12, 42, 62 Instrument transformer 3 ₁ to ₃ 3 _1st to _3rd circuit breakers 11, 41, 61 Cross-through current transformer 20, 50, 70, 110 3E relays 21, 51, 71 Input converters 22, 52, 72 Analog input units 23, 53, 73 Memory 24, 54, 74 Current change rate calculation units 25, 55, 75 Voltage change rate calculation unit 26 , 56 Phase change angle calculation unit 27, 57, 76 Phase difference calculation unit 28, 58, 77 Relay operation processing unit 29, 59, 78 Settling / display unit 30, 60, 79 Input / output unit 31, 61, 80 External device I / F section I _R , I _S , I _T R phase, S phase and T phase current I _R0 , I _S0 , I _T0 normal R phase, S phase and T phase current I _RS composite current I _{(RS) 0} normal the resultant current _{I FR, I FS, I FT} R phase, S phase and T-phase fault current _{V R, V S, V T} R phase S-phase and T-phase voltages V _R0, V _S0, V _T0 normal state R phase, S-phase and T-phase voltages _{V RS, V ST, V TR} RS phase, ST phase and TR phase line voltage V _RS0, V _ST0 , V _TR0 normal RS phase, ST phase and TR phase line voltage T _{1 to} T ₃ First to third trip signals θ _T , θ _RS , θ _ST , θ _TR , θ _RS phase θ _R0 , θ _T0 , Θ _RS0 , θ _ST0 , θ _TR0 , θ _{(RS) 0} Normal phase Δθ _TR , Δθ _T Phase change angle θ Impedance angle K _RS Current change rate L _T , L _RS , L _ST , L _TR Voltage change rate α , beta phase difference alpha _0, beta ₀ TR reference phase difference in the normal time of the phase difference alpha _ST combined current I _RS in ST reference phase difference alpha _TR composite current I _RS of TR reference phase difference beta _RS RS phase line voltage V _RS β _RS0 normal RS phase line voltage V _RS0 TR reference phase difference β _ST ST phase line voltage V _ST RS reference phase difference β _ST0 normal ST phase line voltage V _ST0 RS reference phase difference β _TR TR phase line power ST reference phase difference S10~S18 of TR-phase line voltage V _TR0 of ST reference phase difference beta _TR0 normal of _{V TR, S19a~s19e, S20~S25, S31~S38} , S39a~S39e, S40~S50, S51a~ S51f, S52, S60-S68, S69a-S69e, S70-S76, S81-S96, S92a-S92f, S93, S101-S112, S113a-S113f, S114, S121-S128, S129a-s129e, S130-S135, S141- S152, S153a to S153f, S154, S161 to S172, S173a to S173f, S174 Steps

Claims (5)

三相交流回路の第１および第２の相にそれぞれ流れる第１および第２の相電流（Ｉ_R，Ｉ_S）の差電流（Ｉ_R-S）と、該三相交流回路の１つの線間電圧（Ｖ_TR）または該三相交流回路の１つの線間電圧（Ｖ_TR）および１つの相電圧（Ｖ_T）または該三相交流回路の３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）とに基づいて、該三相交流回路における過負荷、短絡、反相、欠相および断線の発生を検出する三要素保護継電器（２０，５０，７０）を具備することを特徴とする、保護継電システム。 The difference current (I _RS ) between the first and second phase currents (I _R , I _S ) flowing in the first and second phases of the three-phase AC circuit, respectively, and one line voltage of the three-phase AC circuit (V _TR ) or one line voltage (V _TR ) and one phase voltage (V _T ) of the three-phase AC circuit or three line voltages (V _RS , V _ST , V _{TR of the} three-phase AC circuit) And a three-element protective relay (20, 50, 70) for detecting occurrence of overload, short circuit, reverse phase, phase loss and disconnection in the three-phase AC circuit based on Relay system. ２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（１１）と、
前記三相交流回路の前記第１および第３の相間に設けられた計器用変成器（１２）とをさらに具備し、
前記三要素保護継電器（２０）が、
前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）および位相変化角（Δθ_TR）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、
前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）とに基づいて、前記三相交流回路における反相、欠相および断線の発生を検出する、
ことを特徴とする、請求項１記載の保護継電システム。 A cross-penetrating current transformer (11) in which the first and second phases of the three-phase AC circuit are crossed in an opposite direction and at an arbitrary angle through an annular core around which a secondary coil is wound;
An instrument transformer (12) provided between the first and third phases of the three-phase AC circuit;
The three-element protective relay (20)
The current change rate (K _RS ) and phase difference (α) of the combined current (I _RS ) input from the cross-through current transformer and one line voltage (V _TR ) input from the instrument transformer Based on the voltage change rate (L _TR ) and the phase change angle (Δθ _TR ), the occurrence of overload and short circuit in the three-phase AC circuit is detected,
The current change rate (K _RS ) and phase difference (α) of the combined current (I _RS ) input from the cross-through current transformer and one line voltage (V _TR ) input from the instrument transformer Based on the voltage change rate (L _TR ), the occurrence of anti-phase, open phase and disconnection in the three-phase AC circuit is detected.
The protective relay system according to claim 1, wherein: ２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（４１）と、
前記三相交流回路の前記第１および第３の相間に設けられた計器用変成器（４２）とをさらに具備し、
前記三要素保護継電器（５０）が、
前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）および位相変化角（Δθ_TR）と該計器用変成器から入力される１つの相電圧（Ｖ_T）の電圧変化率（Ｌ_T）および位相変化角（Δθ_T）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、
前記合成電流の電流変化率と前記線間電圧の電圧変化率と前記相電圧の電圧変化率および位相差（β）とに基づいて、前記三相交流回路における反相の発生を検出し、
前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および位相差（α）と前記計器用変成器から入力される１つの線間電圧（Ｖ_TR）の電圧変化率（Ｌ_TR）と該計器用変成器から入力される１つの相電圧（Ｖ_T）の電圧変化率（Ｌ_T）とに基づいて、前記三相交流回路における欠相および断線の発生を検出する、
ことを特徴とする、請求項１記載の保護継電システム。 A cross-penetrating current transformer (41) in which the first and second phases of the three-phase AC circuit are crossed in an opposite direction and crossed through an annular core around which a secondary coil is wound;
An instrument transformer (42) provided between the first and third phases of the three-phase AC circuit;
The three-element protective relay (50)
The current change rate (K _RS ) of the combined current (I _RS ) input from the cross-through current transformer and the voltage change rate (L _TR ) of one line voltage (V _TR ) input from the instrument transformer. ) And the phase change angle (Δθ _TR ) and the voltage change rate (L _T ) and phase change angle (Δθ _T ) of one phase voltage (V _T ) input from the instrument transformer, Detects the occurrence of overload and short circuit in the phase AC circuit,
Based on the current change rate of the combined current, the voltage change rate of the line voltage, the voltage change rate of the phase voltage and the phase difference (β), the occurrence of antiphase in the three-phase AC circuit is detected,
The current change rate (K _RS ) and phase difference (α) of the combined current (I _RS ) input from the cross-through current transformer and one line voltage (V _TR ) input from the instrument transformer Based on the voltage change rate (L _TR ) and the voltage change rate (L _T ) of one phase voltage (V _T ) input from the instrument transformer, occurrence of phase loss and disconnection in the three-phase AC circuit Detect
The protective relay system according to claim 1, wherein: ２次コイルを巻装した環状鉄心に前記三相交流回路の前記第１および第２の相を逆向きにかつ任意の角度でクロスさせて貫通させたクロス貫通変流器（６１）と、
前記三相交流回路に設けられた計器用変成器（６２）とをさらに具備し、
前記三要素保護継電器（７０）が、
前記クロス貫通変流器から入力される合成電流（Ｉ_R-S）の電流変化率（Ｋ_R-S）および２つの位相差（α_ST，α_TR）と前記計器用変成器から入力される３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）の電圧変化率（Ｌ_RS，Ｌ_ST，Ｌ_TR）とに基づいて、前記三相交流回路における過負荷および短絡の発生を検出し、
前記合成電流の電流変化率と前記３つの線間電圧の電圧変化率と該３つの線間電圧のうちの１つの線間電圧の位相差（β_RS）とに基づいて、前記三相交流回路における反相の発生を検出し、
前記合成電流の電流変化率および１つの位相差（α_TR）と前記３つの線間電圧（Ｖ_RS，Ｖ_ST，Ｖ_TR）の電圧変化率（Ｌ_RS，Ｌ_ST，Ｌ_TR）および位相差（β_RS，β_ST，β_TR）とに基づいて、前記三相交流回路における欠相および断線の発生を検出する、
ことを特徴とする、請求項１記載の保護継電システム。 A cross-penetrating current transformer (61) in which the first and second phases of the three-phase AC circuit are crossed in opposite directions and at an arbitrary angle through an annular iron core wound with a secondary coil;
An instrument transformer (62) provided in the three-phase AC circuit;
The three-element protective relay (70)
The current change rate (K _RS ) and two phase differences (α _ST , α _TR ) of the combined current (I _RS ) input from the cross-through current transformer and the three lines input from the instrument transformer Based on the voltage change rate (L _RS , L _ST , L _TR ) of the voltage (V _RS , V _ST , V _TR ), the occurrence of overload and short circuit in the three-phase AC circuit is detected,
Based on the current change rate of the combined current, the voltage change rate of the three line voltages, and the phase difference (β _RS ) of one of the three line voltages, the three-phase AC circuit Detecting the occurrence of anti-phase in
Current change rate and one phase difference (α _TR ) of the combined current and voltage change rates (L _RS , L _ST , L _TR ) and phase difference of the three line voltages (V _RS , V _ST , V _TR ) Based on (β _RS , β _ST , β _TR ), it detects the occurrence of phase loss and disconnection in the three-phase AC circuit.
The protective relay system according to claim 1, wherein: 前記合成電流の２つの位相差が、前記三相交流回路の前記第２および第３の相間の第２の線間電圧（Ｖ_ST）の位相（θ_ST）に対する該合成電流の位相差（α_ST）と、該三相交流回路の前記第３および第１の相間の第３の線間電圧（Ｖ_TR）の位相（θ_TR）に対する該合成電流の位相差（α_TR）とであり、
前記３つの線間電圧の位相差が、前記第３の線間電圧（Ｖ_TR）の位相（θ_TR）に対する前記三相交流回路の前記第１および第２の相間の第１の線間電圧（Ｖ_RS）の位相差（β_RS）と、該第１の線間電圧（Ｖ_RS）の位相（θ_RS）に対する前記第２の線間電圧（Ｖ_ST）の位相差（β_ST）と、該第２の線間電圧（Ｖ_ST）の位相（θ_ST）に対する前記第３の線間電圧（Ｖ_TR）の位相差（β_TR）とである、
ことを特徴とする、請求項４記載の保護継電システム。 The two phase differences of the combined current are the phase difference (α of the combined current with respect to the phase (θ _ST ) of the second line voltage (V _ST ) between the second and third phases of the three-phase AC circuit. _ST ) and the phase difference (α _TR ) of the combined current with respect to the phase (θ _TR ) of the third line voltage (V _TR ) between the third and first phases of the three-phase AC circuit,
A phase difference between the three line voltages is a first line voltage between the first and second phases of the three-phase AC circuit with respect to a phase (θ _TR ) of the third line voltage (V _TR ). (V _RS ) phase difference (β _RS ) and phase difference (β _ST ) of the second line voltage (V _ST ) with respect to the phase (θ _RS ) of the first line voltage (V _RS ) A phase difference (β _TR ) of the third line voltage (V _TR ) with respect to the phase (θ _ST ) of the second line voltage (V _ST ).
The protective relay system according to claim 4, wherein: