JP2008005595A - Protective relay - Google Patents

Protective relay Download PDF

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JP2008005595A
JP2008005595A JP2006171211A JP2006171211A JP2008005595A JP 2008005595 A JP2008005595 A JP 2008005595A JP 2006171211 A JP2006171211 A JP 2006171211A JP 2006171211 A JP2006171211 A JP 2006171211A JP 2008005595 A JP2008005595 A JP 2008005595A
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phase current
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Shigeto Oda
重遠 尾田
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective relay which surely determines faulty phase, for the purpose of the solving a conventional current deferential protective relay, wherein it cannot discriminate between a one-phase grounding fault and a two-phase grounding fault though it selects a faulty phase, when the differential output between the zero-phase current at its own end and the zero-phase current at the other party's end amounts to a certain value or larger. <P>SOLUTION: This protective relay is equipped with positive phase/reverse phase/zero phase current generating means for a faulty phase determining, circuit installed in itself. First and second phase judging means are connected to the positive phase current generating means, and first to third phase determining means are connected to the reverse phase current generating means, and first and third phase determining means are connected to the zero phase current generating means and is further equipped with a short-circuited faulty phase determining element which determines the short-circuited faulty phase from the output of the first phase determining means and a grounded faulty phase determining element which determines one-phase/two-phase grounding and the determination of the faulty phase from the output of the second and third phase determining means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

この発明は、直接接地系における電力送電線路を保護する保護継電装置に係るもので、特に送電線路に発生した故障の種類と故障相の判別を行う保護継電装置に関するものである。   The present invention relates to a protective relay device that protects a power transmission line in a direct grounding system, and more particularly to a protective relay device that determines the type and failure phase of a failure that has occurred in a transmission line.

従来の３相送電線の電流差動保護装置において、自端の零相電流と相手端零相電流の差動演算を行う第１の手段と、故障相を判別する第２の手段を備え、第１の手段により零相電流差動出力が一定値以上となったとき、第２の手段により故障相を選択し、故障相のみを選択遮断する電流差動保護装置が示されている（例えば、特許文献１参照）。   In a current differential protection device for a conventional three-phase power transmission line, the device includes a first means for performing a differential operation of a zero-phase current at the end and a zero-phase current at the other end, and a second means for determining a failure phase A current differential protection device is shown in which when a zero-phase current differential output exceeds a certain value by a first means, a fault phase is selected by a second means and only the fault phase is selectively cut off (for example, , See Patent Document 1).

特開昭５７−１１９６１３号公報Japanese Patent Laid-Open No. 57-119613

しかしながら前記特許文献１に示されたものは、１線地絡事故発生時の零相電流と、逆相電流の相対位相関係から故障相を判別するものであり、２相地絡、２相短絡故障の発生時には故障相の判別を行うことは出来ないという問題点がある。
この発明は前記のような課題を解決するためになされたもので、１相地絡、２相地絡、２相短絡故障のいずれかが発生した場合においても、故障相の判定を確実に行う保護継電装置を得ることを目的としている。 However, what is disclosed in Patent Document 1 is to determine the failure phase from the relative phase relationship between the zero-phase current at the time of occurrence of the one-wire ground fault and the reverse-phase current. There is a problem that the failure phase cannot be determined when a failure occurs.
The present invention has been made to solve the above-described problems. Even when one-phase ground fault, two-phase ground fault, or two-phase short-circuit fault occurs, the fault phase is reliably determined. The purpose is to obtain a protective relay device.

この発明に係る保護継電装置は、送電線に設置されたＣＴにより計測された３相の電流を入力として、零相電流と、３相のそれぞれを基準相とする正相電流及び逆相電流とを生成する電流生成手段と、
零相電流が所定の零相電流値より小さく、かつ、３相の何れかの相を基準相とする正相電流と逆相電流との間の位相差が所定の第１の位相差基準値より大きい場合に、その相でない２相間の短絡故障と判定する短絡故障判定要素と、
３相の何れかの相を基準相とする正相電流及び逆相電流と零相電流の位相に関して、逆相電流または零相電流と正相電流との間の位相差が所定の第２の位相差基準値より小さく、かつ、逆相電流と零相電流との間の位相差が所定の第３の位相差範囲内にある場合に、その相が故障相である１相地絡故障と判定する１相地絡故障判定要素と、
３相の何れかの相を基準相とする正相電流及び逆相電流と零相電流の位相に関して、逆相電流または零相電流と正相電流との間の位相差が所定の第２の位相差基準値より大きく、かつ、逆相電流と零相電流との間の位相差が所定の第３の位相差範囲内にある場合に、その相が健全相である２相地絡故障と判定する２相地絡故障判定要素とを有する故障相判定回路を備えたものである。 The protective relay device according to the present invention has a three-phase current measured by CT installed in a transmission line as an input, and a zero-phase current and a positive-phase current and a negative-phase current with each of the three phases as a reference phase. Current generating means for generating
A zero-phase current is smaller than a predetermined zero-phase current value, and a phase difference between a positive-phase current and a negative-phase current having any one of the three phases as a reference phase is a predetermined first phase difference reference value A short-circuit fault determination element that determines a short-circuit fault between two phases that are not the phases when the phase is greater than
The phase difference between the negative phase current or the zero phase current and the positive phase current with respect to the phase of the positive phase current and the negative phase current and the zero phase current with any one of the three phases as a reference phase is a predetermined second value. When the phase difference is smaller than the phase difference reference value and the phase difference between the negative-phase current and the zero-phase current is within a predetermined third phase difference range, A one-phase ground fault determination element for determining;
The phase difference between the negative phase current or the zero phase current and the positive phase current with respect to the phase of the positive phase current and the negative phase current and the zero phase current with any one of the three phases as a reference phase is a predetermined second value. If the phase difference between the negative phase current and the zero phase current is larger than the phase difference reference value and is within a predetermined third phase difference range, the two-phase ground fault that is a healthy phase A fault phase determination circuit having a two-phase ground fault determination element for determination is provided.

この発明に係る保護継電装置には、３相の電流を入力として、零相電流と、３相のそれぞれを基準相とする正相電流及び逆相電流とを生成する電流生成手段と、
零相電流が所定の零相電流基準値より小さく、かつ、３相の何れかの相を基準相とする正相電流と逆相電流との間の位相差が、所定の第１の位相差基準値より大きい場合に、その相でない２相間の短絡故障と判定する短絡故障判定要素と、
３相の何れかの相を基準相とする逆相電流または零相電流と正相電流との間の位相差が、所定の第２の位相差基準値より小さく、かつ、逆相電流と零相電流との間の位相差が、所定の第３の位相差範囲内にある場合に、その相が故障相である１相地絡故障と判定する１相地絡故障判定要素と、
３相の何れかの相を基準相とする逆相電流または零相電流と正相電流との間の位相差が、所定の第２の位相差基準値より大きく、かつ、逆相電流と零相電流との間の位相差が、所定の第３の位相差範囲内にある場合に、基準相が健全相である２相地絡故障と判定する２相地絡故障判定要素と、
を有する故障相判定回路を備えているので、１相地絡、２相地絡、２相短絡の故障区別が出来るとともに、故障相の判定を確実に行えるという効果がある。 In the protective relay device according to the present invention, current generation means for generating a zero-phase current and a positive-phase current and a reverse-phase current with each of the three phases as a reference phase, using a three-phase current as an input,
The zero-phase current is smaller than a predetermined zero-phase current reference value, and the phase difference between the positive-phase current and the negative-phase current having any one of the three phases as a reference phase is a predetermined first phase difference. A short-circuit failure determination element that determines a short-circuit failure between two phases that are not the phase when greater than the reference value;
The phase difference between the negative phase current or the zero phase current and the positive phase current with any one of the three phases as a reference phase is smaller than a predetermined second phase difference reference value, and the negative phase current and zero phase current are zero. A one-phase ground fault determination element for determining that the phase is a one-phase ground fault when the phase difference between the phase currents is within a predetermined third phase difference range;
The phase difference between the negative phase current or the zero phase current and the positive phase current with any one of the three phases as a reference phase is larger than a predetermined second phase difference reference value, and the negative phase current and zero phase current are zero. A two-phase ground fault determination element that determines that the reference phase is a healthy two-phase ground fault when the phase difference between the phase currents is within a predetermined third phase difference range;
Therefore, there is an effect that the fault phase can be discriminated from one-phase ground fault, two-phase ground fault, and two-phase short circuit, and the fault phase can be determined reliably.

実施の形態１．
以下、この発明による実施の形態１を図に基づいて説明する。
図１は実施の形態１による保護継電装置内に設けられた送電線の故障相判定回路の構成図である。また、図２に後述する各電流生成手段および各位相判定手段の詳細構成を示す。
図１において、送電線１に設置されたＣＴ２の３相電流出力ＩＡ、ＩＢ、ＩＣを電流入力手段４にて故障相判定回路３に取り込み、その３相電流ＩＡ、ＩＢ、ＩＣから正相電流Ｉ１、逆相電流Ｉ２、零相電流Ｉ０の各々を、正相電流生成手段５、逆相電流生成手段６、零相電流生成手段７によって、Ａ相を基準相とした場合には下式により演算することで生成する。
Ｉ１＝１／３（ＩＡ＋ａＩＢ＋ａ２ＩＣ）・・・・・正相電流
Ｉ２＝１／３（ＩＡ＋ａ２ＩＢ＋ａＩＣ）・・・・・逆相電流
Ｉ０＝１／３（ＩＡ＋ＩＢ＋ＩＣ） ・・・・・・・零相電流
ここで、ａは、１２０°の移相演算、ａ２は２４０°の移相演算である。
なお、Ｂ相基準では、
Ｉ１＝１／３（ａ２ＩＡ＋ＩＢ＋ａＩＣ）・・・・・正相電流
Ｉ２＝１／３（ａＩＡ＋ＩＢ＋ａ２ＩＣ）・・・・・逆相電流
また、Ｃ相基準では、
Ｉ１＝１／３（ａＩＡ＋ａ２ＩＢ＋ＩＣ）・・・・・正相電流
Ｉ２＝１／３（ａ２ＩＡ＋ａＩＢ＋ＩＣ）・・・・・逆相電流
の式により演算される。 Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a fault phase determination circuit for a power transmission line provided in the protective relay device according to the first embodiment. FIG. 2 shows a detailed configuration of each current generating means and each phase determining means described later.
In FIG. 1, the CT 2 three-phase current outputs IA, IB, IC installed in the transmission line 1 are taken into the fault phase determination circuit 3 by the current input means 4, and the positive-phase currents are obtained from the three-phase currents IA, IB, IC. When each of I 1 , negative phase current I 2 , and zero phase current I 0 is converted into a reference phase by the positive phase current generation means 5, the negative phase current generation means 6, and the zero phase current generation means 7, Generated by calculating with the following formula.
I 1 = 1/3 (IA + aIB + a 2 IC)... Positive phase current I 2 = 1/3 (IA + a 2 IB + aIC)... Reverse phase current I 0 = 1/3 (IA + IB + IC). ... Zero-phase current where a is a 120 ° phase shift calculation and a 2 is a 240 ° phase shift calculation.
In the B phase standard,
I 1 = 1/3 (a 2 IA + IB + aIC) ... Positive phase current I 2 = 1/3 (aIA + IB + a 2 IC) ... Reverse phase current
I 1 = 1/3 (aIA + a 2 IB + IC)... Positive phase current I 2 = 1 (a 2 IA + aIB + IC)...

詳細は後述するように上式で得られたＩ１、Ｉ２、Ｉ０を入力する第１の位相判定手段５１の出力結果に基づいて、短絡故障相判定手段６１にて故障が短絡故障の場合の故障相を判定する。第２の位相判定手段５２と第３の位相判定手段５３の出力に基づいて、地絡故障相判定手段６２にて、故障が地絡故障の場合の故障種類、すなわち１相地絡か２相地絡かの判定と、その故障相の判定を行うよう構成されている。 As will be described in detail later, the short-circuit fault phase determination unit 61 determines that the fault is a short-circuit fault based on the output result of the first phase determination unit 51 that inputs I 1 , I 2 , and I 0 obtained by the above formula. Determine the failure phase of the case. Based on the outputs of the second phase determination unit 52 and the third phase determination unit 53, the ground fault fault phase determination unit 62 determines the fault type when the fault is a ground fault, that is, one phase ground fault or two phase. It is configured to determine whether there is a ground fault and the failure phase.

次に、この構成の故障相判定回路３の動作の理解をより易くするため、その動作原理を図３に基づいて説明する。
図３（ａ）は、Ａ相１相地絡故障時の等価回路を、図３（ｂ）はＢＣ相２相地絡故障時の等価回路を、図３（ｃ）はＢＣ相短絡故障時の等価回路を示す。いずれの図３（ａ）〜図３（ｃ）においても、故障相判定回路３のＣＴ設置点での正相電流Ｉ１、逆相電流Ｉ２、零相電流Ｉ０を矢印記号にて示す。 Next, in order to make it easier to understand the operation of the failure phase determination circuit 3 having this configuration, the operation principle will be described with reference to FIG.
3 (a) shows an equivalent circuit when a phase A / phase one ground fault occurs, FIG. 3 (b) shows an equivalent circuit when a BC phase / two phase ground fault occurs, and FIG. 3 (c) shows a case when a BC phase short circuit fault occurs. The equivalent circuit of is shown. 3A to 3C, the positive phase current I 1 , the negative phase current I 2 , and the zero phase current I 0 at the CT installation point of the failure phase determination circuit 3 are indicated by arrow symbols. .

図３（ａ）から明らかなように、正相電流Ｉ１と逆相電流Ｉ２とは電流方向がほぼ同位相である。また、逆相電流Ｉ２と零相電流Ｉ０も電流方向がほぼ同位相である。図３（ｂ）で明らかなように正相電流Ｉ１と逆相電流Ｉ２は電流方向が逆位相であり、逆相電流Ｉ２と零相電流Ｉ０は電流方向がほぼ同位相である。つまり、地絡故障時において、正相電流Ｉ１と逆相電流Ｉ２が同位相の場合には、１相地絡故障であり、逆位相の場合には２相地絡故障である。 FIGS. 3 (a) As is apparent from the positive phase current I 1 and the reverse-phase current I 2 current direction is substantially the same phase. Further, the reverse-phase current I 2 and the zero-phase current I 0 also have substantially the same current direction. As is apparent from FIG. 3B, the current direction of the positive phase current I 1 and the negative phase current I 2 is opposite in phase, and the current direction of the negative phase current I 2 and zero phase current I 0 is substantially in phase. . That is, at the time of a ground fault, when the normal phase current I 1 and the reverse phase current I 2 are in the same phase, it is a one-phase ground fault and when it is in the reverse phase, it is a two-phase ground fault.

また、逆相電流Ｉ２と零相電流Ｉ０が同位相の場合、１相地絡故障では逆相電流Ｉ２演算の基準相が故障相と判定できる。２相地絡故障ではＩ２演算の基準相が健全相と判定できるので、地絡の故障種類（１相地絡、２相地絡）と故障相の判定が可能になる。また短絡故障と地絡故障の区別は、零相電流Ｉ０の有無により判定できる。すなわち零相電流Ｉ０がある場合は地絡故障、零相電流Ｉ０が無い場合には短絡故障となる。 Further, when the reverse phase current I 2 and the zero phase current I 0 are in the same phase, it is possible to determine that the reference phase of the reverse phase current I 2 calculation is a fault phase in the case of a one-phase ground fault. In the two-phase ground fault, since the reference phase of the I 2 calculation can be determined as a healthy phase, it is possible to determine the fault type (one-phase ground fault, two-phase ground fault) and the fault phase. The distinction between short-circuit failure and the ground fault can be determined by the presence or absence of the zero-phase current I 0. That is, when there is a zero-phase current I 0-ground fault, a short-circuit fault when there is no zero-phase current I 0.

図３（ｃ）に示すＢＣ相短絡故障時の等価回路から、正相電流Ｉ１、逆相電流Ｉ２の位相が、Ａ相基準の正相電流Ｉ１、逆相電流Ｉ２で逆位相となることがわかる。この様子を図４（ａ）〜図４（ｃ）により説明する。
図４（ａ）はＡ相基準のＢＣ相短絡故障時の電流ベクトル関係を示し、Ｉ１（正相電流）、Ｉ２（逆相電流）は逆位相であることが分かる。図４（ｂ）はＢ相基準のＢＣ相短絡故障時の電流ベクトル関係を示し、Ｉ１、Ｉ２は逆位相ではなく、１２０°以内の位相関係に位置することが分かる。図４（ｃ）はＣ相基準のＢＣ相短絡故障時の電流ベクトル関係を示し、Ｉ１、Ｉ２は逆位相ではなく、１２０°以内の位相関係に位置することが分かる。即ち、Ｉ１、Ｉ２の位相関係により、例えば、Ａ相基準演算の場合、逆位相であれば、ＢＣ相が故障相であり、逆にＡ相が健全相であることが判断できる。 From the equivalent circuit at the time of the BC phase short-circuit failure shown in FIG. 3C, the phase of the positive phase current I 1 and the negative phase current I 2 is the negative phase of the positive phase current I 1 and the negative phase current I 2 based on the A phase. It turns out that it becomes. This will be described with reference to FIGS. 4 (a) to 4 (c).
FIG. 4A shows the current vector relationship when the BC phase short-circuit fault is based on the A phase, and it can be seen that I 1 (positive phase current) and I 2 (reverse phase current) are in reverse phase. FIG. 4B shows the current vector relationship at the time of the BC phase short-circuit fault based on the B phase, and it can be seen that I 1 and I 2 are not in opposite phases but in a phase relationship within 120 °. FIG. 4C shows the current vector relationship when the C-phase reference BC-phase short-circuit fault occurs, and it can be seen that I 1 and I 2 are not in opposite phases but in a phase relationship within 120 °. That is, from the phase relationship between I 1 and I 2 , for example, in the case of the A phase reference calculation, if the phase is opposite, it can be determined that the BC phase is a failure phase and conversely the A phase is a healthy phase.

上記に基づいて、Ｉ１（正相電流）、Ｉ２（逆相電流）、Ｉ０（零相電流）の各電流信号によって、故障相を判定するこの実施の形態１による回路の詳細説明を図５に基づいて行う。
図５は、前述した図１の故障相判定回路３に示された各手段から、第１〜第３の位相判定手段５１〜５３と、短絡故障相判定要素６１、地絡故障相判定要素６２の部分のみを取り出し、その内部構成の概要を示す図であり、第１、第２、第３の位相判定手段５１、５２、５３のブロック図と、短絡故障相判定要素６１、地絡故障相判定要素６２のブロック図を示す。図６は各電流生成手段５〜６と、各位相判定手段５１〜５３との信号授受を示す詳細図である。正相電流生成手段５は、図６に示すようにＡ相、Ｂ相、Ｃ相の３相それぞれを基準相として正相電流Ｉ１を生成する。逆相電流生成手段６は、同じ相を基準相とする逆相電流Ｉ２を生成する。零相電流生成手段７は、Ａ相、Ｂ相、Ｃ相の零相電流Ｉ０を生成する。
図５に示した第１の位相判定手段５１は、逆位相判定手段２１と、短絡故障判定手段２２と、第１のＡＮＤ回路２３により構成されており、さらに詳しくは図６に示すように、逆位相判定手段２１は各相を基準相とする３個の逆位相判定手段２１−Ａ、２１−Ｂ、２１−Ｃより構成されている。すなわち第１の位相判定手段５１は、正相、逆相、零相各電流生成手段５、６、７から入力される正相電流Ｉ１と逆相電流Ｉ２との位相差が、所定の第１の位相差基準値である角度θ３（例えば１２０°）より大きい、即ち逆位相を判定する逆位相差判定２１−Ａ〜２１−Ｃと、零相電流Ｉ０＜Ｋ１（零相電流基準値である電流なしを判定する所定の設定値）により短絡故障と判定する短絡故障判定手段２２とのＡＮＤ条件を判定する第１のＡＮＤ手段２３により構成され、この第１の位相判定手段５１に接続される短絡故障相判定要素６１が３相の中の何れかの相において、前記第１のＡＮＤ手段２３が１（真）を出力する場合に、１（真）を出力する前記第１のＡＮＤ手段２３に対応する相が健全相である２相短絡故障と判断する。 Based on the above, a detailed description of the circuit according to the first embodiment in which a fault phase is determined based on current signals of I 1 (positive phase current), I 2 (reverse phase current), and I 0 (zero phase current) will be described. Based on FIG.
FIG. 5 shows the first to third phase determination means 51 to 53, the short-circuit fault phase determination element 61, and the ground fault fault phase determination element 62 from the means shown in the fault phase determination circuit 3 of FIG. FIG. 5 is a diagram showing an outline of the internal configuration of the first, second, and third phase determination means 51, 52, and 53, a short-circuit fault phase determination element 61, and a ground fault phase A block diagram of the decision element 62 is shown. FIG. 6 is a detailed diagram showing signal transmission / reception between each of the current generating means 5-6 and each of the phase determining means 51-53. As shown in FIG. 6, the positive phase current generating means 5 generates a positive phase current I 1 using the three phases of A phase, B phase, and C phase as reference phases. Reverse-phase current generating means 6 generates a negative sequence current I 2 for the same phase as the reference phase. Zero phase current generation means 7 generates zero phase current I 0 of A phase, B phase, and C phase.
The first phase determination means 51 shown in FIG. 5 includes an anti-phase determination means 21, a short circuit failure determination means 22, and a first AND circuit 23. More specifically, as shown in FIG. The anti-phase determining means 21 is composed of three anti-phase determining means 21-A, 21-B, 21-C having each phase as a reference phase. That is, the first phase determination means 51 has a predetermined phase difference between the positive phase current I 1 and the negative phase current I 2 input from the positive phase, negative phase, and zero phase current generation means 5, 6, and 7. More than the first phase difference reference value angle θ3 (for example, 120 °), that is, reverse phase difference determinations 21-A to 21-C for determining a reverse phase, and zero phase current I 0 <K1 (zero phase current reference) The first AND means 23 for judging the AND condition with the short-circuit fault judging means 22 for judging the short-circuit fault according to the predetermined set value for judging that there is no current as a value. When the first AND means 23 outputs 1 (true) in any one of the three phases of the short-circuit fault phase determination element 61 to be connected, the first output that outputs 1 (true) It is determined that the two-phase short-circuit fault in which the phase corresponding to the AND means 23 is a healthy phase.

図５に示した第２の位相判定手段５２は、第１の同位相差判定手段２４が設けられており、さらに詳しくは図６に示すように各相を基準相とする３個の第１の位相差判定手段２４−Ａ、２４−Ｂ、２４−Ｃにより構成されている。そしてこの第１の位相差判定手段２４−Ａ〜２４−Ｃは、正相電流生成手段５が生成する３相のそれぞれを基準相とする正相電流Ｉ１と、逆相電流生成手段６が生成する同じ相を基準相とする逆相電流Ｉ２との間の位相差が所定の第２の位相差基準値である角度θ２（例えば１２０度）以内である場合に、同位相と判定する。 The second phase determination means 52 shown in FIG. 5 is provided with the first same phase difference determination means 24, and more specifically, as shown in FIG. The phase difference determination means 24-A, 24-B, and 24-C are configured. And this first phase difference determination unit 24-A~24-C includes a positive-phase current I 1 as a reference phase of each three-phase positive phase current generating means 5 for generating, reverse-phase current generating means 6 When the phase difference between the generated opposite phase current I 2 having the same phase as the reference phase is within a predetermined second phase difference reference value angle θ2 (for example, 120 degrees), the phase is determined to be the same phase. .

また、図５に示した第３の位相判定手段５３は、第２の同位相差判定手段２５が設けられており、さらに詳しくは図６に示すように各相を基準相とする３個の第２の同位相差判定手段２５−Ａ、２５−Ｂ、２５−Ｃにより構成されている。そしてこの第２の位相差判定手段２５−Ａ〜２５−Ｃは、逆相電流生成手段６が生成する同じ相を基準相とする逆相電流Ｉ２と、零相電流生成手段７の生成する零相電流Ｉ０との間の位相差が所定の第３の位相差である角度θ１（例えば１２０度）以内である場合に、同位相と判定する。 Further, the third phase determination means 53 shown in FIG. 5 is provided with a second same phase difference determination means 25, and more specifically, as shown in FIG. 2 in-phase difference determination means 25-A, 25-B, 25-C. And this second phase difference determination unit 25-A~25-C includes a negative sequence current I 2 for the same phase negative sequence current generating means 6 generates a reference phase, and generates a zero-phase current generating means 7 When the phase difference from the zero-phase current I 0 is within a predetermined third phase difference angle θ1 (for example, 120 degrees), it is determined that the phase is the same.

前記第２、第３の位相判定手段５２、５３に接続される地絡故障相判定要素６２は、前記第１の同位相差判定手段２４と、前記同位相差判定手段２５の出力がともに１（真）であるため１（真）を出力する第３のＡＮＤ手段２７がある場合に１相故障であり、かつ、１（真）を出力する第３のＡＮＤ手段２７に対応する相が１相地絡故障相であると判定する１相地絡故障相判定手段２９と、前記第２の同位相差判定手段２５の出力と、前記第１の同位相差判定手段２４の出力を否定したものとを入力とする第２のＡＮＤ手段２６の中で、１（真）を出力するものがある場合に、１（真）を出力する第３のＡＮＤ手段２７に対応する相が２相地絡故障の健全相であるという判定をする健全相判定手段２８で構成される。なお第２、第３の位相判定手段５２、５３における位相判定は、例えば正相電流Ｉ１と零相電流Ｉ０の場合、図７に示すような論理式にて計算を行っている。
この図７のような構成とする目的は、位相差を検出する対象の電流が零に近い場合は位相が不定になり位相差が正しく判断できないので、位相差が正しく判断できない場合は条件が成立しないようにするためである。ε１とε２は、それぞれＩ１とＩ０が電流ゼロ付近の誤差分に対して十分に大きい値であることを判断するための所定値である。ε１とε２は、適切に判断できるように適宜調整する。第１の位相差判定手段５１に関しても、同様な構成とする。 The ground fault failure phase determination element 62 connected to the second and third phase determination units 52 and 53 has outputs of 1 (true) for both the first phase difference determination unit 24 and the phase difference determination unit 25. ), There is a one-phase failure when there is a third AND means 27 that outputs 1 (true), and the phase corresponding to the third AND means 27 that outputs 1 (true) is one phase. 1 phase ground fault failure phase determination means 29 for determining that it is a fault fault phase, the output of the second in-phase difference determination means 25, and the negation of the output of the first in-phase difference determination means 24 Among the second AND means 26 that outputs 1 (true), the phase corresponding to the third AND means 27 that outputs 1 (true) is a healthy two-phase ground fault. It is composed of sound phase determination means 28 for determining that the phase is a phase. Note that the phase determination in the second and third phase determination means 52 and 53 is performed by a logical expression as shown in FIG. 7 in the case of the positive phase current I 1 and the zero phase current I 0 , for example.
The purpose of the configuration as shown in FIG. 7 is that if the current to be detected is close to zero, the phase becomes indefinite and the phase difference cannot be judged correctly. If the phase difference cannot be judged correctly, the condition is satisfied. This is to prevent it from happening. ε 1 and ε 2 are predetermined values for determining that I 1 and I 0 are sufficiently large with respect to an error near zero current, respectively. ε 1 and ε 2 are adjusted as appropriate so that they can be appropriately determined. The first phase difference determination unit 51 has the same configuration.

なお、上記した所定の位相角θ１〜θ３に関して、
逆相電流Ｉ２と零相電流Ｉ０の位相差＜θ１におけるθ１の望しい値として、
逆相電流Ｉ２は零相電流Ｉ０に対して＋６０°〜−９０°
の範囲に設定する。
より具体的には、例えば＋６０°〜−６０°の範囲、あるいは＋３０°〜−９０°の範囲、もしくは前記２つの動作範囲の間の間隔１２０°の動作範囲に設定する。この理由は、２相地絡の場合には、図３（ｂ）に示すように逆相回路と零相回路が並列になるので、逆相電流Ｉ２は逆相インピーダンスで決まり、零相電流Ｉ０は零相インピーダンスで決まる。そのため、逆相電流Ｉ２と零相電流Ｉ０の位相は同じになるとは限らず、零相インピーダンスの方が抵抗分の割合が大きいため、逆相電流Ｉ２の方が零相電流Ｉ０より遅れ位相の場合が多いので、逆相電流Ｉ２が零相電流Ｉ０に対して遅れ９０度〜進み６０度の範囲と、遅れの方の範囲を大きくしている。
また、正相電流Ｉ１と逆相電流Ｉ２の位相差＜θ２におけるθ２の望ましい値として、
｜Ｉ１とＩ２の位相差｜＜θ２、９０°＜θ２≦１２０°
の範囲に設定し、
さらに、正相電流Ｉ１と逆相電流Ｉ２の位相差＜θ３におけるθ３の望ましい値として、
｜Ｉ１とＩ２の位相差｜＜θ３、９０°＜θ３≦１２０°
の範囲に設定する。なお、位相角θ１〜θ３は前記の値に限られるものではなく、系統の有する諸定数によって変更されるものである。 In addition, regarding the above-described predetermined phase angles θ1 to θ3,
As a desired value of θ1 when the phase difference between the negative phase current I 2 and the zero phase current I 0 <θ1,
The reverse phase current I 2 is + 60 ° to −90 ° with respect to the zero phase current I 0 .
Set to the range.
More specifically, for example, a range of + 60 ° to −60 °, a range of + 30 ° to −90 °, or an operating range of 120 ° between the two operating ranges is set. This is because, in the case of 2-phase ground fault, since the reverse-phase circuit and the zero-phase circuit as shown in FIG. 3 (b) becomes in parallel, negative sequence current I 2 is determined by reversed-phase impedance, zero-phase current I 0 is determined by zero phase impedance. Therefore, the phase of the negative-phase current I 2 and the zero-phase current I 0 is not necessarily the same, and the zero-phase impedance has a larger resistance ratio, so that the negative-phase current I 2 is the zero-phase current I 0. Since there are many cases where the phase is delayed, the reverse phase current I 2 is larger than the zero phase current I 0 in the range of 90 ° to 60 ° and the range of the delay.
Further, as the desired value of .theta.2 in the positive phase current I 1 and the reverse-phase current phase difference of I 2 <.theta.2,
| Phase difference between I 1 and I 2 | <θ2, 90 ° <θ2 ≦ 120 °
To the range of
Further, as a desirable value of θ3 when the phase difference between the positive phase current I 1 and the negative phase current I 2 <θ3,
| Phase difference between I 1 and I 2 | <θ3, 90 ° <θ3 ≦ 120 °
Set to the range. The phase angles θ1 to θ3 are not limited to the above values, but are changed according to various constants of the system.

以上のように、この実施の形態１による保護継電装置に設けられた故障相判定回路は、ＣＴ２から入力する３相電流から正相、逆相、零相電流を生成して、それらの位相関係から故障相の判定をするとともに零相電流で短絡，地絡故障区別を実施し、故障相判定を行うように構成したものである。したがって、１相地絡、２相地絡、２相短絡故障のいずれかが発生したとしても、電流情報のみで故障相の判定を確実に実施することができるという効果がある。   As described above, the fault phase determination circuit provided in the protection relay device according to the first embodiment generates the positive phase, the negative phase, and the zero phase current from the three-phase current input from CT2, and the phase The fault phase is determined from the relationship, and the fault phase is determined by distinguishing between short-circuit and ground faults with zero-phase current. Therefore, even if any one-phase ground fault, two-phase ground fault, and two-phase short-circuit fault occurs, there is an effect that the fault phase can be reliably determined only by the current information.

実施の形態２．
実施の形態１では、第２の位相判定手段５２において正相電流Ｉ１と逆相電流Ｉ２の位相差により判定したが、逆相電流Ｉ２と零相電流Ｉ０はほぼ同位相であるので、図８に示すように逆相電流Ｉ２の代わりに零相電流Ｉ０を用いて、正相電流Ｉ１と零相電流Ｉ０の位相差を第１の同位相差判定手段２４ａで判定することでも同様に故障相判定が実現できる。図８において５２ａは、地絡故障の種類を判定する正相電流Ｉ１、零相電流Ｉ０の第２の位相判定手段である。前記以外は実施の形態１と同様であるので説明省略する。このようにして実施の形態１と同様に電流情報により故障相の判定が可能となる。なお、所定の位相角θ１〜θ３は前述した実施の形態１と同程度の値を設定する。 Embodiment 2. FIG.
In the first embodiment, has been determined by the phase difference of the positive phase current I 1 and the reverse-phase current I 2 in the second phase determination means 52, the reverse-phase current I 2 and the zero-phase current I 0 is nearly the same phase Therefore, as shown in FIG. 8, the phase difference between the positive phase current I 1 and the zero phase current I 0 is determined by the first in-phase difference determination means 24a using the zero phase current I 0 instead of the reverse phase current I 2. The failure phase determination can be realized in the same manner. In FIG. 8, 52a is the second phase determination means for the positive phase current I 1 and the zero phase current I 0 for determining the type of ground fault. Since other than the above is the same as in the first embodiment, description thereof is omitted. In this way, the failure phase can be determined from the current information as in the first embodiment. The predetermined phase angles θ1 to θ3 are set to values similar to those in the first embodiment.

実施の形態３．
実施の形態１では、正相電流Ｉ１の演算としてＩ１＝１／３（ＩＡ＋ａＩＢ＋ａ２ＩＣ）により算出したが、実際には、入力３相電流には故障電流だけでなく、故障前の負荷電流も重ね合わされているので、負荷電流の影響を受け、位相角が変化する。そのために、図９に示すように故障相判定回路３に電流入力手段４に接続される負荷電流削除手段３０を設け、３相入力電流から故障前の負荷電流を差し引いた電流をもとに正相電流ＩＡ’を算出することで位相角がより正しくなる。即ち、例えばＡ相を基準相とした場合には、
ＩＡ’＝ＩＡ−ＩＬＡ
ＩＢ’＝ＩＢ−ＩＬＢ
ＩＣ’＝ＩＣ−ＩＬＣ
Ｉ１＝１／３（ＩＡ’＋ａＩＢ’＋ａ２ＩＣ’）
ここで、ＩＬＡ，ＩＬＢ，ＩＬＣは、故障前負荷電流である。
なお、逆相電流／零相電流生成手段６、７は、電流入力手段４に接続されている。前記以外は実施の形態１と同様であるので説明省略する。尚、この実施の形態３と前記実施の形態２を組み合わせてもよい。このような実施の形態３の構成を採用することにより精度よい正相電流Ｉ１が得られ、故障相判定の信頼性が向上する効果がある。 Embodiment 3 FIG.
In the first embodiment, I 1 = 1/3 (IA + aIB + a 2 IC) is calculated as the calculation of the positive phase current I 1 , but actually, the input three-phase current is not only the fault current but also the load before the fault. Since the current is also superimposed, the phase angle changes under the influence of the load current. For this purpose, as shown in FIG. 9, the failure phase determination circuit 3 is provided with a load current deletion unit 30 connected to the current input unit 4, and is corrected based on the current obtained by subtracting the load current before the failure from the three-phase input current. By calculating the phase current IA ′, the phase angle becomes more correct. That is, for example, when the A phase is set as the reference phase,
IA '= IA-ILA
IB '= IB-ILB
IC '= IC-ILC
I 1 = 1/3 (IA ′ + aIB ′ + a 2 IC ′)
Here, ILA, ILB, and ILC are pre-failure load currents.
The negative phase current / zero phase current generating means 6 and 7 are connected to the current input means 4. Since other than the above is the same as in the first embodiment, description thereof is omitted. The third embodiment and the second embodiment may be combined. By adopting such a configuration of the third embodiment, an accurate positive phase current I 1 can be obtained, and the reliability of failure phase determination is improved.

この発明の実施の形態１〜３は、電力送電線を保護する保護継電装置に利用できる。   Embodiments 1 to 3 of the present invention can be used for a protective relay device that protects a power transmission line.

実施の形態１の保護継電装置に設けられた故障相判定回路の概要を示す構成図である。FIG. 3 is a configuration diagram showing an overview of a fault phase determination circuit provided in the protective relay device of the first embodiment. 実施の形態１の故障判定回路の詳細を示す図である。FIG. 3 is a diagram illustrating details of a failure determination circuit according to the first embodiment. 実施の形態１の故障相判定回路の動作原理を説明する図である。FIG. 3 is a diagram for explaining an operation principle of the failure phase determination circuit according to the first embodiment. 実施の形態１の故障相判定回路の動作原理を説明する図である。FIG. 3 is a diagram for explaining an operation principle of the failure phase determination circuit according to the first embodiment. 実施の形態１の故障相判定回路内の位相判定手段、短絡／地絡故障相判定回路の内部手段を示す図である。It is a figure which shows the internal means of the phase determination means in the fault phase determination circuit of Embodiment 1, and a short circuit / ground fault fault phase determination circuit. 実施の形態１の故障相判定回路の詳細を示す図である。FIG. 3 is a diagram illustrating details of a failure phase determination circuit according to the first embodiment. 実施の形態１の位相判定手段の論理を示す図である。FIG. 3 is a diagram illustrating the logic of a phase determination unit according to the first embodiment. 実施の形態２の故障相判定回路内の位相判定手段、短絡／地絡故障相判定回路の内部手段を示す図である。It is a figure which shows the internal means of the phase determination means in the fault phase determination circuit of Embodiment 2, and a short circuit / ground fault fault phase determination circuit. 実施の形態３の故障相判定回路内の位相判定手段、短絡／地絡故障相判定回路の内部手段を示す図である。It is a figure which shows the internal means of the phase determination means in the fault phase determination circuit of Embodiment 3, and a short circuit / ground fault fault phase determination circuit.

符号の説明Explanation of symbols

１ 送電線、２ ＣＴ、３ 故障相判定回路、４ 電流入力手段、
５ 正相電流生成手段、６ 逆相電流生成手段、７ 零相電流生成手段、
２１ 逆位相差判定手段、２２ 短絡故障判定手段、２３ 第１のＡＮＤ手段、
２４ 第１の同位相差判定手段、２５ 第２の同位相差判定手段、
２６ 第２のＡＮＤ手段、２７ 第３のＡＮＤ手段、２８ ２相地絡健全相判定手段、
２９ １相地絡故障相判定手段、３０ 負荷電流削除手段、
５１ 第１の位相判定手段、５２，５２ａ 第２の位相判定手段、
５３ 第３の位相判定手段、６１ 短絡故障相判定要素、６２ 地絡故障相判定要素。 1 transmission line, 2 CT, 3 fault phase determination circuit, 4 current input means,
5 positive phase current generating means, 6 reverse phase current generating means, 7 zero phase current generating means,
21 anti-phase difference determination means, 22 short-circuit failure determination means, 23 first AND means,
24 first in-phase difference determining means, 25 second in-phase difference determining means,
26 second AND means, 27 third AND means, 28 two-phase ground fault healthy phase determination means,
29 1-phase ground fault fault phase determination means, 30 load current deletion means,
51 1st phase determination means, 52,52a 2nd phase determination means,
53 3rd phase determination means, 61 Short-circuit fault phase determination element, 62 Ground fault fault phase determination element

Claims (5)

送電線に設置されたＣＴにより計測された３相の電流を入力として、零相電流と、３相のそれぞれを基準相とする正相電流及び逆相電流とを生成する電流生成手段と、
前記零相電流が所定の零相電流値より小さく、かつ、前記３相の何れかの相を基準相とする前記正相電流と前記逆相電流との間の位相差が所定の第１の位相差基準値より大きい場合に、その相でない２相間の短絡故障と判定する短絡故障判定要素と、
前記３相の何れかの相を基準相とする前記正相電流及び前記逆相電流と前記零相電流の位相に関して、前記逆相電流または前記零相電流と前記正相電流との間の位相差が所定の第２の位相差基準値より小さく、かつ、前記逆相電流と前記零相電流との間の位相差が所定の第３の位相差範囲内にある場合に、その相が故障相である１相地絡故障と判定する１相地絡故障判定要素と、
前記３相の何れかの相を基準相とする前記正相電流及び前記逆相電流と前記零相電流の位相に関して、前記逆相電流または前記零相電流と前記正相電流との間の位相差が所定の第２の位相差基準値より大きく、かつ、前記逆相電流と前記零相電流との間の位相差が所定の第３の位相差範囲内にある場合に、その相が健全相である２相地絡故障と判定する２相地絡故障判定要素とを有する故障相判定回路を備えたことを特徴とする保護継電装置。 Current generation means for generating a zero-phase current and a positive-phase current and a reverse-phase current with each of the three phases as a reference phase, using as input the three-phase current measured by the CT installed in the transmission line;
The zero-phase current is smaller than a predetermined zero-phase current value, and a phase difference between the positive-phase current and the negative-phase current having any one of the three phases as a reference phase is a predetermined first A short-circuit fault determination element that determines a short-circuit fault between two phases that are not the phase when the phase difference reference value is greater than the phase difference reference value;
Regarding the phase of the positive phase current and the negative phase current and the zero phase current with any one of the three phases as a reference phase, the phase between the negative phase current or the zero phase current and the positive phase current If the phase difference is smaller than a predetermined second phase difference reference value and the phase difference between the negative phase current and the zero phase current is within a predetermined third phase difference range, the phase is faulty. A one-phase ground fault determination element for determining a one-phase ground fault that is a phase;
Regarding the phase of the positive phase current and the negative phase current and the zero phase current with any one of the three phases as a reference phase, the phase between the negative phase current or the zero phase current and the positive phase current When the phase difference is larger than a predetermined second phase difference reference value and the phase difference between the negative phase current and the zero phase current is within a predetermined third phase difference range, the phase is healthy. A protective relay device comprising a fault phase determination circuit having a two-phase ground fault determination element that determines a two-phase ground fault as a phase. 送電線のＣＴにより計測される３相の電流から故障前の負荷電流を除く負荷電流削除手段を備え、少なくとも前記正相電流を求める際に、前記電流生成手段が前記負荷電流削除手段により処理された各相の電流を使用することを特徴とする請求項１に記載の保護継電装置。 Load current deleting means for removing the load current before the failure from the three-phase current measured by CT of the transmission line is provided, and at least when obtaining the positive phase current, the current generating means is processed by the load current deleting means. The protective relay device according to claim 1, wherein a current of each phase is used. 前記第１の位相差基準値を９０度より大きく１２０度以下の所定の値とすることを特徴とする請求項１に記載の保護継電装置。 2. The protective relay device according to claim 1, wherein the first phase difference reference value is a predetermined value greater than 90 degrees and equal to or less than 120 degrees. 前記第２の位相差基準値を９０度より大きく１２０度以下の所定の値とすることを特徴とする請求項１に記載の保護継電装置。 2. The protective relay device according to claim 1, wherein the second phase difference reference value is a predetermined value greater than 90 degrees and equal to or less than 120 degrees. 前記第３の位相差範囲を、前記逆相電流が前記零相電流に対して９０度の遅れから６０度の進みまでの範囲とすることを特徴とする請求項１に記載の保護継電装置。 2. The protective relay device according to claim 1, wherein the third phase difference range is a range in which the reverse-phase current is from a delay of 90 degrees to an advance of 60 degrees with respect to the zero-phase current. .
JP2006171211A 2006-06-21 2006-06-21 Protective relay Pending JP2008005595A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009194988A (en) * 2008-02-13 2009-08-27 Mitsubishi Electric Corp Zero-phase current differential relay
CN113945858A (en) * 2021-02-02 2022-01-18 保定钰鑫电气科技有限公司 Three-phase non-effective grounding power supply system convenient for processing single-phase grounding fault

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009194988A (en) * 2008-02-13 2009-08-27 Mitsubishi Electric Corp Zero-phase current differential relay
CN113945858A (en) * 2021-02-02 2022-01-18 保定钰鑫电气科技有限公司 Three-phase non-effective grounding power supply system convenient for processing single-phase grounding fault
CN113945858B (en) * 2021-02-02 2024-03-01 保定钰鑫电气科技有限公司 Three-phase non-effective grounding power supply system convenient for processing single-phase grounding fault

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