JP5570360B2

JP5570360B2 - Protection relay malfunction prevention device

Info

Publication number: JP5570360B2
Application number: JP2010204339A
Authority: JP
Inventors: 友也大丸; 和弘沖本
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2010-09-13
Filing date: 2010-09-13
Publication date: 2014-08-13
Anticipated expiration: 2030-09-13
Also published as: JP2012060858A

Description

この発明は、送電を停止している送電線における保護継電器の誤動作を防止する保護継電器の誤動作防止装置に関するものである。 The present invention relates to a protection relay malfunction prevention device that prevents malfunction of a protection relay in a transmission line that stops power transmission.

電力系統が、２回線送電などの複数回線送電システムとして構成されている場合、送電が停止されている送電線（以下、停止回線と称する）に、送電中の送電線（以下、運用回線と称する）からの電磁誘導による誘導電流が流れる。この場合、停止回線におけるＵ相、Ｖ相、Ｗ相（以下、各相と称する）の送電線の各々と運用回線の各相の送電線の各々との線間の距離が異なるため、停止回線の各相の送電線に流れる誘導電流は同じにはならず、三相不平衡電流となる。 When the power system is configured as a multi-line power transmission system such as a two-line power transmission, a transmission line (hereinafter referred to as an operation line) that is transmitting power to a transmission line (hereinafter referred to as a stop line) in which power transmission is stopped. ) Induced current by electromagnetic induction flows. In this case, since the distances between the U-phase, V-phase, and W-phase (hereinafter referred to as each phase) transmission lines in the stop line and the transmission lines in each phase of the operation line are different, the stop line The induced currents flowing in the transmission lines of each phase are not the same, but become three-phase unbalanced currents.

夫々の回線の送電線には受電線が接続されているが、夫々の回線に接続された受電線を選択的に運転、若しくは停止させるための遮断器は、一般的に配電盤、金属閉鎖形スイッチギア、ガス絶縁開閉装置など（以下、これらを総称して、配電盤と総称する）に内蔵される。また、この配電盤内には、夫々の回線の受電線毎に、接地開閉器、地絡過電流継電器などの保護継電器が設けられている。また、配電盤内の受電線を構成する各相の受電ケーブルには、その受電ケーブルを一次導体とする変流器が夫々設けられており、それらの変流器の出力回路の電流が合成されて保護継電器に動作電流として入力される。 Each power line is connected to a power receiving line, but the circuit breaker for selectively operating or stopping the power receiving line connected to each line is generally a switchboard, metal closed switch Built in gears, gas-insulated switchgear and the like (hereinafter collectively referred to as switchboard). In addition, a protective relay such as a ground switch and a ground fault overcurrent relay is provided in the distribution board for each receiving line of each line. In addition, each phase of the power receiving cable constituting the power receiving line in the switchboard is provided with a current transformer having the power receiving cable as a primary conductor, and the currents of the output circuits of those current transformers are combined. Input to the protective relay as operating current.

周知のように、夫々の回線の送電線は、両端に設けられた遮断器をオンとすることで運用回線とされ、両端の遮断器をオフとすることで停止回線とされるが、停止回線とされた送電線の両端に設けられている接地開閉器は、安全上、接地側へ切り換えられる。従って、前述の誘導電流は、停止回線の各相の送電線から配電盤内の受電線に設けられた各相の接地開閉器を介してアースへ流れる。その結果、受電線を構成する各相の受電ケーブルを流れる誘導電流は、その受電ケーブルの各々を一次導体とする前述の各相の変流器の出力回路にも三相不平衡電流として現れる。 As is well known, the transmission line of each line is set as an operation line by turning on the breakers provided at both ends, and is set as a stop line by turning off the breakers at both ends. The ground switches provided at both ends of the transmission line are switched to the ground side for safety. Therefore, the above-described induced current flows from the transmission line of each phase of the stop line to the ground via the ground switch of each phase provided on the receiving wire in the switchboard. As a result, the induced current flowing through the power receiving cable of each phase constituting the power receiving wire also appears as a three-phase unbalanced current in the output circuit of the above-described current transformer of each phase using the power receiving cable as a primary conductor.

一方、運用回線を停止回線へ切り換える際、当該回線の両端の遮断器を開放した後、当該回線の両端の接地開閉器を接地側に切り換えるが、その切り換え時に瞬時的に、対地静電容量から接地側に切り換えた接地開閉器を介してアースへの放電電流が流れる。当該回線の両端の遮断器を開放する際、遮断器の裁断電流により対地静電容量に充電される電荷は三相不平衡であるため、前述の放電電流もまた三相不平衡電流となる。 On the other hand, when switching the operation line to the stop line, after opening the circuit breakers at both ends of the line, the earthing switches at both ends of the line are switched to the ground side. A discharge current to the earth flows through the ground switch switched to the ground side. When the circuit breakers at both ends of the circuit are opened, the electric charge charged to the ground capacitance by the cutting current of the circuit breaker is three-phase unbalanced, so the above-described discharge current also becomes a three-phase unbalanced current.

前述の対地静電容量の放電電流は、配電盤内では受電線の各相の受電ケーブルから配電盤内の接地開閉器を介してアースへ流れる。従って、受電線の各相の受電ケーブルを流れる放電電流は、前述の各相の変流器の二次電流にも三相不平衡電流として現れる。 The above-mentioned discharge current of the electrostatic capacitance flows from the power receiving cable of each phase of the power receiving wire to the ground through the grounding switch in the power distribution panel in the power distribution board. Therefore, the discharge current flowing through the power receiving cable of each phase of the power receiving wire also appears as a three-phase unbalanced current in the secondary current of each phase current transformer described above.

このように、送電を停止した受電線の各相の受電ケーブルを流れる三相不平衡電流である誘導電流または放電電流により、各相の変流器の出力回路に流れる二次電流もまた三相不平衡電流となり、各相の変流器の二次電流が合成されて入力される保護継電器は、不要な動作、あるいは誤動作をする可能性がある。 In this way, the secondary current that flows in the output circuit of each phase current transformer is also three-phase due to the induction current or discharge current that is the three-phase unbalanced current that flows through the power receiving cable of each phase of the power receiving line that has stopped transmitting power. There is a possibility that an unbalanced current is generated, and the protective relay to which the secondary currents of the current transformers of the respective phases are combined and inputted may cause unnecessary operation or malfunction.

従来、前述のような三相不平衡誘導電流または三相不平衡放電電流に基づく保護継電器の誤作動を防止するため、三相各相の接地開閉器の相別接地線を、周囲から絶縁された短絡板により短絡し、この短絡板に接続された一本の短絡接地線を零相変流器の一次導体貫通孔に貫通させ、この短絡接地線に一次導体とは逆極性の電流を通電するようにした装置が提案されている（例えば、特許文献１参照）。 Conventionally, in order to prevent the malfunction of the protective relay based on the three-phase unbalanced induction current or the three-phase unbalanced discharge current as described above, the phase-separated ground wire of each three-phase ground switch is insulated from the surroundings. Short-circuited by the short-circuit plate, and one short-circuit ground wire connected to the short-circuit plate is passed through the primary conductor through hole of the zero-phase current transformer, and a current having a polarity opposite to that of the primary conductor is passed through the short-circuit ground wire. An apparatus has been proposed (see, for example, Patent Document 1).

また、従来、三相不平衡誘導電流または三相不平衡放電電流に基づく保護継電器の誤作動を防止するようにした従来の装置として、以下に示す装置がある。即ち、図１３は、従来の保護継電器の誤動作防止装置を示す構成図、図１４は、従来の保護継電器の誤動作防止装置を適用した電力系統の構成図である。 Conventional devices that prevent malfunction of the protective relay based on the three-phase unbalanced induction current or the three-phase unbalanced discharge current are as follows. 13 is a block diagram showing a conventional protection relay malfunction prevention device, and FIG. 14 is a power system configuration diagram to which a conventional protection relay malfunction prevention device is applied.

図１４に示す電力系統は、２回線送電システムとして構成されており、運用回線Ｌ１は、オン状態の遮断器ＣＢ１１を介して変電所Ｓ／Ｓから２２［ＫＶ］の高電圧で送電中である。停止回線Ｌ２は、オフ状態の遮断器ＣＢ２１により変電所Ｓ／Ｓから遮断され、送電を停止している。運用回線Ｌ１および停止回線Ｌ２は、夫々Ｕ相、Ｖ相、Ｗ相の各相から成る三相の送電線により構成され、鉄塔ＴＴにより周知のように支持されている。運用回線Ｌ１および停止回線Ｌ２は、夫々、接地開閉器ＥＳが設けられており、接地開閉器ＥＳの接地側は接地抵抗ＲＥを介して接地されている。 The power system shown in FIG. 14 is configured as a two-line power transmission system, and the operation line L1 is transmitting power at a high voltage of 22 [KV] from the substation S / S via the on-state circuit breaker CB11. . The stop line L2 is disconnected from the substation S / S by the circuit breaker CB21 in the off state, and stops power transmission. The operation line L1 and the stop line L2 are each composed of a three-phase transmission line composed of a U-phase, a V-phase, and a W-phase, and are supported by a steel tower TT as is well known. The operation line L1 and the stop line L2 are each provided with a ground switch ES, and the ground side of the ground switch ES is grounded via a ground resistor RE.

運用回線Ｌ１に接続された受電線ＲＬ１と、停止回線Ｌ２に接続された受電線ＲＬ２は、夫々遮断器ＣＢ１２、ＣＢ２２を介して給電線ＦＬ１、ＦＬ２に接続される。図１４では、運用回線Ｌ１に接続されている受電線ＲＬ１の遮断器ＣＢ１２はオン状態、停止回線Ｌ２に接続されている受電線ＲＬ２の遮断器ＣＢ２２はオフ状態にある。 The receiving line RL1 connected to the operation line L1 and the receiving line RL2 connected to the stop line L2 are connected to the feeder lines FL1 and FL2 via the circuit breakers CB12 and CB22, respectively. In FIG. 14, the circuit breaker CB12 of the receiving line RL1 connected to the operation line L1 is in the on state, and the circuit breaker CB22 of the receiving line RL2 connected to the stop line L2 is in the off state.

また、受電線ＲＬ１、ＲＬ２は、夫々接地開閉器ＥＳを介して接地抵抗ＲＥにより接地可能な構造とされている。変圧器Ｔｒ１、Ｔｒ２は、運用回線Ｌ１から受電線ＲＬ１、遮断器ＣＢ１２、および給電線ＦＬ１を介して供給された２２［ＫＶ］の高電圧を例えば１００［Ｖ］若しくは２００［Ｖ］の電圧に降圧し、負荷Ｌに供給する。受電線ＲＬ１、ＲＬ２、および給電線ＦＬ１、ＦＬ２は、夫々Ｕ相、Ｖ相、Ｗ相の受電ケーブル、および給電ケーブルにより構成されている。 In addition, the receiving wires RL1 and RL2 can be grounded by the grounding resistor RE via the grounding switch ES. The transformers Tr1 and Tr2 convert the high voltage of 22 [KV] supplied from the operation line L1 via the receiving line RL1, the circuit breaker CB12, and the feeder line FL1 to a voltage of 100 [V] or 200 [V], for example. The voltage is stepped down and supplied to the load L. Receiving wires RL1 and RL2 and feeding lines FL1 and FL2 are constituted by U-phase, V-phase and W-phase receiving cables and feeding cables, respectively.

受電線ＲＬ１、ＲＬ２に夫々設けられた保護継電器としての地絡過電流継電器５１Ｇは、後述するように、受電線ＲＬ１、ＲＬ２を構成する各相の受電ケーブルを夫々一次導体とする各相の変流器ＣＴの出力回路に共通接続された共通回路としての残留回路が接続されており、その残留回路に流れる電流に基づいて動作する。更に、受電線ＲＬ１、ＲＬ２の各相の受電ケーブルには接地開閉器ＥＳを介して接地抵抗ＲＥにより接地可能な構造とされており、その接地開閉器ＥＳと接地箇所との間を接続する接地回路が各相の変流器ＣＴの一次導体貫通孔内を貫通している。 As will be described later, a ground fault overcurrent relay 51G as a protective relay provided in each of the receiving wires RL1 and RL2 is a current transformation of each phase in which each phase of the receiving cables constituting the receiving wires RL1 and RL2 is a primary conductor. A residual circuit as a common circuit connected in common to the output circuit of the device CT is connected, and operates based on the current flowing through the residual circuit. Further, the power receiving cables of each phase of the receiving wires RL1 and RL2 are structured to be grounded by a grounding resistor RE through a grounding switch ES, and grounding for connecting between the grounding switch ES and a grounding location. The circuit passes through the primary conductor through hole of each phase current transformer CT.

配電盤ＤＳＢは、受電線ＲＬ１、ＲＬ２の各相の受電ケーブルと、給電線ＦＬ１、ＦＬ２を構成する各相の給電ケーブルの一部と、遮断器ＣＢ１２、ＣＢ２２と、接地開閉器ＥＳと、接地抵抗器ＲＥと、変流器ＣＴ、および地絡過電流継電器５１Ｇを収納している。 Distribution board DSB includes power receiving cables for each phase of power receiving lines RL1 and RL2, a part of power feeding cables for each phase constituting power feeding lines FL1 and FL2, circuit breakers CB12 and CB22, grounding switch ES, and grounding resistance. The device RE, the current transformer CT, and the ground fault overcurrent relay 51G are housed.

図１３に示す保護継電器の誤動作防止装置は、図１４に示す受電線ＲＬ１、ＲＬ２に夫々設けられている保護継電器としての地絡過電流継電器５１Ｇの誤動作防止装置のうち、停止回線Ｌ２に接続されている受電線ＲＬ２に設けられた地絡過電流継電器の誤動作防止装置をより詳細に示したものである。なお、受電線ＲＬ１に夫々設けられている保護継電器としての地絡過電流継電器５１Ｇの誤動作防止装置は、受電線ＲＬ２に設けられている保護継電器の誤動作防止装置と同一の構成である。 The malfunction prevention device of the protective relay shown in FIG. 13 is connected to the stop line L2 among the malfunction prevention devices of the ground fault overcurrent relay 51G as the protective relay provided in the receiving wires RL1 and RL2 shown in FIG. The malfunction prevention apparatus of the ground-fault overcurrent relay provided in the receiving wire RL2 is shown in more detail. In addition, the malfunction prevention apparatus of the ground fault overcurrent relay 51G as a protective relay provided in each of the receiving lines RL1 has the same configuration as the malfunction prevention apparatus of the protective relay provided in the receiving line RL2.

図１３において、各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷは、図１４に示す受電線ＲＬ２に対応する。各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷは、図１４における受電線ＲＬ２に設けられた変流器ＣＴに対応する。各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷには一次導体貫通孔が設けられており、各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷが対応する各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの一次導体貫通孔内を貫通している。各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路はＹ結線され、その中性線である残留回路ＲＣＣが地絡過電流継電器５１Ｇの入力側に接続されている。即ち、この残留回路ＲＣＣは、各相の変流器ＣＴＵ、ＣＴＶ，ＣＴＷの出力回路を共通に接続する共通回路に相当する。 In FIG. 13, each phase of the power receiving cables ICU, ICV, ICW corresponds to the power receiving line RL2 shown in FIG. The current transformers CTU, CTV, and CTW of each phase correspond to the current transformer CT provided in the receiving wire RL2 in FIG. Each phase current transformer CTU, CTV, CTW is provided with a primary conductor through hole, and the primary conductor of each phase current transformer CTU, CTV, CTW to which each phase receiving cable ICU, ICV, ICW corresponds. It penetrates through the through hole. The output circuits of the current transformers CTU, CTV, and CTW of each phase are Y-connected, and the residual circuit RCC, which is a neutral line, is connected to the input side of the ground fault overcurrent relay 51G. That is, the residual circuit RCC corresponds to a common circuit that commonly connects the output circuits of the current transformers CTU, CTV, and CTW of the respective phases.

各相の接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷは、図１４における接地開閉器ＥＳに対応し、それらの接地側接点は、各相の接地回路ＥＣＵ、ＥＣＶ、ＥＣＷを介してＹ結線され、その中性線が接地抵抗ＲＥ（図１３には図示せず）を介して接地される。 The ground switches ESU, ESV, ESW of each phase correspond to the ground switch ES in FIG. 14, and their ground side contacts are Y-connected through the ground circuits ECU, ECV, ECW of each phase, The ground wire is grounded via a grounding resistor RE (not shown in FIG. 13).

Ｕ相の接地開閉器ＥＳＵの接地側接点に接続されたＵ相の接地回路ＥＣＵは、Ｕ相の受電ケーブルＩＣＵに対して逆極性となるようにＵ相の変流器ＣＴＵの一次導体貫通孔を貫通している。Ｖ相の接地開閉器ＥＳＶの接地側接点に接続されたＶ相の接地回路ＥＣＶは、Ｖ相の受電ケーブルＩＣＶに対して逆極性となるようにＶ相の変流器ＣＴＶの一次導体貫通孔を貫通している。Ｗ相の接地開閉器ＥＳＷの接地側接点に接続されたＷ相の接地回路ＥＣＷは、Ｗ相の受電ケーブルＩＣＷに対して逆極性となるようにＷ相の変流器ＣＴＷの一次導体貫通孔を貫通している。 The U-phase ground circuit ECU connected to the ground-side contact of the U-phase ground switch ESU is a primary conductor through hole of the U-phase current transformer CTU so as to have a reverse polarity with respect to the U-phase power receiving cable ICU. It penetrates. The V-phase ground circuit ECV connected to the ground-side contact of the V-phase ground switch ESV has a primary conductor through-hole of the V-phase current transformer CTV so as to have a reverse polarity with respect to the V-phase power receiving cable ICV. It penetrates. The W-phase grounding circuit ECW connected to the ground-side contact of the W-phase grounding switch ESW has a primary conductor through-hole of the W-phase current transformer CTW so as to have a reverse polarity with respect to the W-phase power receiving cable ICW. It penetrates.

次に、以上のように構成された従来の保護継電器の誤動作防止装置の動作について説明する。図１３、図１４において、送電が停止されている停止回線Ｌ２に、送電中である運用回線Ｌ１に流れる電流に基づく電磁誘導作用により誘導電流が流れる。この場合、停止回線Ｌ２における各相の送電線の各々と運用回線Ｌ１の各相の送電線の各々との線間の距離が異なるため、停止回線Ｌ２の各相の送電線の各々に流れる誘導電流は同じにはならず、従って、各相の誘導電流は三相不平衡電流の状態になる。 Next, the operation of the conventional protective relay malfunction prevention apparatus configured as described above will be described. 13 and 14, an induced current flows through the stop line L2 where power transmission is stopped by an electromagnetic induction action based on a current flowing through the operation line L1 during power transmission. In this case, since the distance between each transmission line of each phase in the stop line L2 and each transmission line of each phase of the operation line L1 is different, the induction that flows to each transmission line of each phase of the stop line L2 The currents will not be the same, so the induced current in each phase will be in a three-phase unbalanced current state.

停止回線Ｌ２の両端の接地開閉器ＥＳは、安全上、接地側へ切り換えられている。従って、前述の誘導電流は、配電盤ＤＳＢ内では、図１４に矢印で示すように、受電線ＲＬ２の各相の受電ケーブルから、各相の接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷの接地側接点、接地回路ＥＣＵ、ＥＣＶ、ＥＣＷ、共通接地回路ＣＥＣ、および接地抵抗ＲＥを介してアースへ流れる。 The ground switch ES at both ends of the stop line L2 is switched to the ground side for safety. Therefore, in the distribution board DSB, the above-described induced current is transmitted from the power receiving cable of each phase of the receiving wire RL2 to the ground side contacts ESU, ESV, ESW of each phase, as shown by arrows in FIG. It flows to the ground through the circuit ECU, ECV, ECW, common ground circuit CEC, and ground resistor RE.

ここで、受電線ＲＬ２の各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷと、各相の接地回路ＥＣＵ、ＥＣＶ、ＥＣＷとは、互いに逆方向の電流が流れるように、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの一次導体貫通孔を貫通しているので、前述の誘導電流が流れても各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの二次回路からは出力が発生しない。従って、受電線ＲＬ２に流れる誘導電流が三相不平衡電流であっても、地絡過電流継電器５１Ｇに入力される電流は零であり、地絡過電流継電器５１Ｇの誤動作は防止される。 Here, current receiving cables ICU, ICV, ICW for each phase of power receiving line RL2 and grounding circuits ECU, ECV, ECW for each phase have current transformers CTU, Since it penetrates the primary conductor through-holes of CTV and CTW, no output is generated from the secondary circuits of the current transformers CTU, CTV and CTW of each phase even if the above-described induced current flows. Therefore, even if the induced current flowing through the receiving line RL2 is a three-phase unbalanced current, the current input to the ground fault overcurrent relay 51G is zero, and the malfunction of the ground fault overcurrent relay 51G is prevented.

また、運用回線Ｌ１を停止回線に切り換える際、前述したように、瞬時的に対地静電容量から接地側に切り換えた接地開閉器ＥＳを介してアースへ放電電流が流れるが、この放電電流もまた三相不平衡の状態となる。 Further, when the operation line L1 is switched to the stop line, as described above, a discharge current flows to the ground via the ground switch ES that is instantaneously switched from the ground capacitance to the ground side. It becomes a three-phase unbalanced state.

配電盤ＤＳＢ内では、前述の対地静電容量の放電電流は、受電線ＲＬ２の各相の受電ケーブルから、配電盤ＤＳＢ内の各相の接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷの接地側接点、接地回路ＥＣＵ、ＥＣＶ、ＥＣＷ、共通接地回路ＣＥＣ、および接地抵抗ＲＥを介してアースへ流れる。 In the switchboard DSB, the discharge current of the above-mentioned ground capacitance is supplied from the power receiving cable of each phase of the power receiving line RL2, from the ground side contacts ESU, ESV, ESW of each phase in the switchboard DSB, to the ground circuit ECU. , ECV, ECW, common ground circuit CEC, and ground resistance RE.

しかし前述したように、受電線ＲＬ２の各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷと、各相の接地回路ＥＣＵ、ＥＣＶ、ＥＣＷとは、互いに逆方向に電流が流れるように各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの一次導体貫通孔を貫通しているので、前述の放電電流が流れても各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの二次回路からは出力が発生しない。従って、受電線ＲＬ２に放電電流が三相不平衡電流であっても、地絡過電流継電器５１Ｇに入力される電流は零であり、地絡過電流継電器５１Ｇの誤動作は防止される。 However, as described above, the current receiving cables ICU, ICV, ICW of each phase of the receiving wire RL2 and the ground circuits ECU, ECV, ECW of each phase are current transformers of each phase so that currents flow in opposite directions. Since it passes through the primary conductor through-holes of CTU, CTV, and CTW, no output is generated from the secondary circuits of the current transformers CTU, CTV, and CTW of each phase even when the aforementioned discharge current flows. Therefore, even if the discharge current is a three-phase unbalanced current in the receiving line RL2, the current input to the ground fault overcurrent relay 51G is zero, and the malfunction of the ground fault overcurrent relay 51G is prevented.

特開平９−３２２３４２号公報JP-A-9-322342

特許文献１に示された従来の装置の場合、地絡検出に零相変流器を用いる必要があり、各相に設置される変流器の出力回路の残留回路を利用した地絡検出方法には適していなかった。また、短絡板に接続された一本の短絡接地線を零相変流器の一次導体貫通孔に一次導体と逆極性に通す必要があるため、当該接地線を零相変流器の一次導体貫通孔に通さない場合より長くする必要があるなどの課題があった。 In the case of the conventional apparatus shown in Patent Document 1, it is necessary to use a zero-phase current transformer for ground fault detection, and a ground fault detection method using a residual circuit of an output circuit of a current transformer installed in each phase It was not suitable for. In addition, since it is necessary to pass a single short-circuit ground wire connected to the short-circuit plate through the primary conductor through hole of the zero-phase current transformer in the opposite polarity to the primary conductor, the ground wire is the primary conductor of the zero-phase current transformer. There existed problems, such as having to make it longer than the case where it does not pass through a through-hole.

一方、図１３、図１４に示す従来の装置の場合、停止回線を運用回線に切り換える際に、その停止回線に接続されている受電線の接地開閉器を接地側に選択切換した状態のまま、停止回線の変電所側端の遮断器を誤ってオン操作してしまうこともあり得る。この場合、数千〜数万［Ａ］という極めて大きな短絡電流が受電線に接続された各相の接地回路に流れることになる。従って、その接地回路の各導体の線径は、当該短絡電流に耐え得る大きな線径としておく必要がある。 On the other hand, in the case of the conventional apparatus shown in FIGS. 13 and 14, when the stop line is switched to the active line, the grounding switch of the receiving wire connected to the stop line remains selected and switched to the ground side. It is possible to accidentally turn on the circuit breaker at the substation side end of the stop line. In this case, an extremely large short-circuit current of several thousand to several tens of thousands [A] flows in the ground circuit of each phase connected to the receiving wire. Therefore, the wire diameter of each conductor of the ground circuit needs to be large enough to withstand the short-circuit current.

しかし、接地回路の各導体の線径を、前述の短絡電流に耐え得る大きな線径とした場合は、かかる大径の接地回路の導体は変流器の一次導体貫通孔に通すことはできないので、変流器の一次導体貫通孔の径を大きくし外径も大きくした特殊な変流器とする必要があり、変流器自体が高価なものになるだけでなく、変流器の外径も大きくなることから、当該変流器の配電盤内における占有率も大きくなり、配電盤の小型化と逆行するといった課題がある。 However, if the wire diameter of each conductor of the ground circuit is a large wire diameter that can withstand the short-circuit current, the conductor of the large-diameter ground circuit cannot pass through the primary conductor through hole of the current transformer. It is necessary to make the current transformer's primary conductor through-hole diameter larger and the outer diameter larger, and the current transformer itself is not only expensive, but also the outer diameter of the current transformer Therefore, the occupation ratio of the current transformer in the switchboard also increases, and there is a problem that it goes against the miniaturization of the switchboard.

この発明は、従来の装置に於ける前述のような課題を解決するためになされたもので、零相変流器を用いずしかも装置の大型化を招くことなく、保護継電器の誤動作を確実に防止できる保護継電器の誤動作防止装置を提供することを目的とするものである。 The present invention has been made to solve the above-mentioned problems in the conventional apparatus, and without using a zero-phase current transformer, and without enlarging the apparatus, it is possible to reliably prevent malfunction of the protective relay. It is an object of the present invention to provide a protective relay malfunction prevention device that can be prevented.

この発明による保護継電器の誤動作防止装置は、三相交流電路の各相の電路を夫々一次導体とする複数個の変流器の出力回路に共通接続された共通回路に流れる電流に基づいて動作する保護継電器に対する誤動作防止装置であって、前記各相の電路は、送電停止時に接地開閉器を介して接地されるように構成されており、前記接地開閉器が前記接地を行う動作に基づいて駆動され、前記複数個の変流器の出力回路を短絡すると共に前記複数個の変流器の夫々の出力回路と前記共通回路とのうちの少なくとも一方を遮断するスイッチ手段を備えたことを特徴とするものである。 The protection relay malfunction prevention device according to the present invention operates based on a current flowing in a common circuit commonly connected to output circuits of a plurality of current transformers each having a primary conductor of each phase of the three-phase AC circuit. A malfunction prevention device for a protective relay, wherein the electric circuit of each phase is configured to be grounded via a grounding switch when power transmission is stopped, and is driven based on an operation in which the grounding switch performs the grounding And a switch means for short-circuiting the output circuits of the plurality of current transformers and interrupting at least one of the output circuits of the plurality of current transformers and the common circuit. To do.

また、この発明による保護継電器の誤動作防止装置は、三相交流電路の各相の電路を夫々一次導体とする複数個の変流器の出力回路を共通に接続した共通回路に流れる電流に基づいて動作する保護継電器に対する誤動作防止装置であって、前記各相の電路は、送電停止時に接地開閉器を介して接地されるように構成されており、前記接地開閉器が前記接地を行う動作の途中に連動して閉じる第１の接地開閉器連動接点と、前記接地開閉器が前記接地を行う動作の完了に連動して閉じる第２の接地開閉器連動接点と、前記第１の接地開閉器連動接点と前記第２の接地開閉器連動接点とのうちの少なくとも一方が閉じたときに動作し、前記複数個の変流器の夫々の出力回路を短絡すると共に前記複数個の変流器の夫々の出力回路と前記共通回路とのうちの少なくとも一方を遮断するスイッチ手段とを備えたことを特徴とするものである。 Further, the malfunction prevention device of the protective relay according to the present invention is based on the current flowing in the common circuit in which the output circuits of a plurality of current transformers each having a primary conductor for each phase of the three-phase AC circuit are connected. A malfunction prevention device for an operating protective relay, wherein the electric circuit of each phase is configured to be grounded via a grounding switch when power transmission is stopped, and the grounding switch is in the middle of the operation of performing the grounding A first earthing switch interlocking contact that closes in conjunction with the first earthing switch, a second earthing switch interlocking contact that closes in conjunction with completion of the operation of the earthing switch performing the grounding, and the first earthing switch interlocking. It operates when at least one of the contact and the second earthing switch interlocking contact is closed, short-circuits the output circuit of each of the plurality of current transformers, and each of the plurality of current transformers. Output circuit and the common circuit It is characterized in that a switching means for interrupting at least one of out.

この発明による保護継電器の誤動作防止装置は、接地開閉器が接地を行う動作に基づいて駆動され、複数個の変流器の出力回路を短絡すると共に複数個の変流器の夫々の出力回路と共通回路とのうちの少なくとも一方を遮断するスイッチ手段を備えたので、零相変流器を用いずしかも装置の大型化を招くことなく、誘導電流若しくは放電電流による保護継電器の誤動作を防止することができる効果がある。 The protective relay malfunction prevention device according to the present invention is driven based on an operation in which a grounding switch performs grounding, short-circuits output circuits of a plurality of current transformers, and outputs each of the plurality of current transformers. Since switch means for cutting off at least one of the common circuit is provided, it is possible to prevent malfunction of the protective relay due to induced current or discharge current without using a zero-phase current transformer and without increasing the size of the device. There is an effect that can.

また、この発明による保護継電器の誤動作防止装置は、接地開閉器が接地を行う動作の途中に連動して閉じる第１の接地開閉器連動接点と、接地開閉器が接地を行う動作の完了に連動して閉じる第２の接地開閉器連動接点と、前記第１の接地開閉器連動接点と前記第２の接地開閉器連動接点とのうちの少なくとも一方が閉じたときに動作し、複数個の変流器の夫々の出力回路を短絡すると共に前記複数個の変流器の夫々の出力回路とその共通回路とのうちの少なくとも一方を遮断するスイッチ手段とを備えたので、零相変流器を用いずしかも装置の大型化を招くことなく、誘導電流若しくは放電電流による保護継電器の誤動作を確実に防止することができる効果がある。 In addition, the protection relay malfunction prevention device according to the present invention is linked to the first earthing switch interlocking contact that closes in the middle of the operation of the earthing switch performing the earthing, and the completion of the operation of the earthing switch to perform the earthing. And when the second earthing switch interlocking contact, the first earthing switch interlocking contact, and the second earthing switch interlocking contact are closed, a plurality of variable A switch means for short-circuiting each output circuit of the current transformer and shutting off at least one of the output circuit of each of the plurality of current transformers and the common circuit; There is an effect that it is possible to reliably prevent malfunction of the protective relay due to induction current or discharge current without using it and increasing the size of the apparatus.

この発明の実施の形態１による保護継電器の誤動作防止装置を示す構成図である。It is a block diagram which shows the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention. この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統の構成図である。It is a block diagram of the electric power system to which the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention is applied. この発明の実施の形態１による保護継電器の誤動作防止装置における第１のスイッチ手段及び第２のスイッチ手段の動作コイルの接続状態を示す説明図である。It is explanatory drawing which shows the connection state of the operating coil of the 1st switch means and the 2nd switch means in the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention. この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統の送電用鉄塔における送電線の配置を示す説明図である。It is explanatory drawing which shows arrangement | positioning of the power transmission line in the power transmission tower of the electric power system to which the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention is applied. この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、運用回線と停止回線との電磁結合の視点での等価回路を示す説明図である。It is explanatory drawing which shows the equivalent circuit from the viewpoint of the electromagnetic coupling of an operation line and a stop line in the electric power system to which the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention is applied. この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、停止回線のＵ相送電線の相互リアクタンスを示す説明図である。It is explanatory drawing which shows the mutual reactance of the U-phase power transmission line of a stop line in the electric power system to which the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention is applied.

この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、停止回線のＶ相送電線の相互リアクタンスを示す説明図である。It is explanatory drawing which shows the mutual reactance of the V-phase power transmission line of a stop line in the electric power system to which the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention is applied. この発明の実施の形態１による保護継電器の誤動作防止装置を適用した別の電力系統の構成図である。It is a block diagram of another electric power system which applied the malfunction prevention apparatus of the protection relay by Embodiment 1 of this invention. 図８に示す電力系統における、対地静電容量を通して流れる充電電流を示す説明図である。It is explanatory drawing which shows the charging current which flows through a ground electrostatic capacitance in the electric power system shown in FIG. 図８に示す電力系統における、対地静電容量に充電される電荷を示す説明図である。It is explanatory drawing which shows the electric charge charged to a ground electrostatic capacitance in the electric power system shown in FIG. 図８に示す電力系統における、対地静電容量から流れる放電電流を示す説明図である。It is explanatory drawing which shows the discharge current which flows from a ground electrostatic capacitance in the electric power system shown in FIG.

この発明の実施の形態２による保護継電器の誤動作防止装置を示す構成図である。It is a block diagram which shows the malfunction prevention apparatus of the protection relay by Embodiment 2 of this invention. 従来の保護継電器の誤動作防止装置を示す構成図である。It is a block diagram which shows the malfunction prevention apparatus of the conventional protective relay. 従来の保護継電器の誤動作防止装置を適用した電力系統の構成図である。It is a block diagram of the electric power system to which the malfunction prevention apparatus of the conventional protective relay is applied.

実施の形態１．
図１は、この発明の実施の形態１による保護継電器の誤動作防止装置を示す構成図、図２は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統の構成図である。図２に示す電力系統は、２回線送電システムとして構成されており、運用回線Ｌ１は、オン状態の遮断器ＣＢ１１を介して変電所Ｓ／Ｓから２２［ＫＶ］の高電圧で送電中である。停止回線Ｌ２は、オフ状態の遮断器ＣＢ２１により変電所Ｓ／Ｓから遮断され、送電を停止している。運用回線Ｌ１および停止回線Ｌ２は、夫々、Ｕ相、Ｖ相、Ｗ相（以下、単に、各相と称する）から成る三相送電線により構成され、鉄塔ＴＴにより周知のように支持されている。運用回線Ｌ１および停止回線Ｌ２は、夫々、接地開閉器ＥＳおよび接地抵抗ＲＳが設けられている。 Embodiment 1 FIG.
FIG. 1 is a block diagram showing a protection relay malfunction prevention device according to Embodiment 1 of the present invention, and FIG. 2 is a power system configuration diagram to which a protection relay malfunction prevention device according to Embodiment 1 of the present invention is applied. is there. The power system shown in FIG. 2 is configured as a two-line power transmission system, and the operation line L1 is transmitting power at a high voltage of 22 [KV] from the substation S / S via the on-state circuit breaker CB11. . The stop line L2 is disconnected from the substation S / S by the circuit breaker CB21 in the off state, and stops power transmission. The operation line L1 and the stop line L2 are each composed of a three-phase transmission line composed of a U phase, a V phase, and a W phase (hereinafter simply referred to as each phase), and is supported by a steel tower TT as is well known. . The operation line L1 and the stop line L2 are each provided with a ground switch ES and a ground resistance RS.

運用回線Ｌ１に接続された受電線ＲＬ１と、停止回線Ｌ２に接続された受電線ＲＬ２は、夫々遮断器ＣＢ１２、ＣＢ２２を介して給電線ＦＬ１、ＦＬ２に接続される。図２では、運用回線Ｌ１に接続されている受電線ＲＬ１の遮断器ＣＢ１２はオン状態、停止回線Ｌ２に接続されている受電線ＲＬ２の遮断器ＣＢ２２はオフ状態にある。受電線ＲＬ１、ＲＬ２は、夫々接地開閉器ＥＳを介して接地抵抗ＲＥにより接地可能な構造とされている。変圧器Ｔｒ１、Ｔｒ２は、運用回線Ｌ１から受電線ＲＬ１、遮断器ＣＢ１２、および給電線ＦＬ１を介して供給された２２［ＫＶ］の高電圧を例えば１００［Ｖ］若しくは２００［Ｖ］の電圧に降圧し、負荷Ｌに供給する。受電線ＲＬ１、ＲＬ２、および給電線ＦＬ１、ＦＬ２は、夫々、各相の受電ケーブル、及び給電ケーブルにより構成されている。 The receiving line RL1 connected to the operation line L1 and the receiving line RL2 connected to the stop line L2 are connected to the feeder lines FL1 and FL2 via the circuit breakers CB12 and CB22, respectively. In FIG. 2, the circuit breaker CB12 of the receiving line RL1 connected to the operation line L1 is on, and the circuit breaker CB22 of the receiving line RL2 connected to the stop line L2 is off. The receiving wires RL1 and RL2 can be grounded by a grounding resistor RE via a grounding switch ES. The transformers Tr1 and Tr2 convert the high voltage of 22 [KV] supplied from the operation line L1 via the receiving line RL1, the circuit breaker CB12, and the feeder line FL1 to a voltage of 100 [V] or 200 [V], for example. The voltage is stepped down and supplied to the load L. Receiving wires RL1 and RL2 and feeding lines FL1 and FL2 are constituted by a receiving cable and a feeding cable for each phase, respectively.

受電線ＲＬ１、ＲＬ２に夫々設けられた保護継電器としての地絡過電流継電器５１Ｇは、後述するように、受電線ＲＬ１、ＲＬ２を構成する各相の受電ケーブルを夫々一次導体とする各相の変流器ＣＴの出力回路に共通接続された共通回路としての残留回路が接続されており、その残留回路に流れる電流に基づいて動作する。更に、受電線ＲＬ１、ＲＬ２の各相の受電ケーブルには接地開閉器ＥＳを介して接地抵抗ＲＥにより接地可能な構造とされている。 As will be described later, a ground fault overcurrent relay 51G as a protective relay provided in each of the receiving wires RL1 and RL2 is a current transformation of each phase in which each phase of the receiving cables constituting the receiving wires RL1 and RL2 is a primary conductor. A residual circuit as a common circuit connected in common to the output circuit of the device CT is connected, and operates based on the current flowing through the residual circuit. Further, the power receiving cables of each phase of the receiving wires RL1 and RL2 are configured to be grounded by a grounding resistor RE through a grounding switch ES.

配電盤ＤＳＢは、受電線ＲＬ１、ＲＬ２の各相の受電ケーブルと、給電線ＦＬ１、ＦＬ２を構成する各相の給電ケーブルの一部と、遮断器ＣＢ１２、ＣＢ２２と、接地開閉器ＥＳと、接地抵抗器ＲＥと、変流器ＣＴ、および地絡過電流５１Ｇを収納している。 Distribution board DSB includes power receiving cables for each phase of power receiving lines RL1 and RL2, a part of power feeding cables for each phase constituting power feeding lines FL1 and FL2, circuit breakers CB12 and CB22, grounding switch ES, and grounding resistance. The generator RE, the current transformer CT, and the ground fault overcurrent 51G are housed.

図１に示すこの発明の実施の形態１による保護継電器の誤動作防止装置は、図２に示す受電線ＲＬ１、ＲＬ２に夫々設けられている地絡過電流継電器５１Ｇの誤動作防止装置のうち、停止回線Ｌ２に接続されている受電線ＲＬ２に設けられた保護継電器の誤動作防止装置をより詳細に示したものである。なお、受電線ＲＬ１に夫々設けられている地絡過電流継電器５１Ｇの誤動作防止装置は、受電線ＲＬ２に設けられている保護継電器の誤動作防止装置と同一の構成である。 The malfunction prevention device for the protective relay according to Embodiment 1 of the present invention shown in FIG. 1 is the stop line L2 among the malfunction prevention devices for the ground fault overcurrent relay 51G provided in the receiving wires RL1 and RL2 shown in FIG. The malfunction prevention apparatus of the protective relay provided in the receiving wire RL2 connected to is shown in detail. In addition, the malfunction prevention apparatus of the ground fault overcurrent relay 51G each provided in the receiving wire RL1 is the same structure as the malfunction prevention apparatus of the protective relay provided in the receiving line RL2.

図１において、受電線の各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷは、図２に示す受電線ＲＬ２に対応する。各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷは、図２における受電線ＲＬ２に設けられた変流器ＣＴに対応する。変流器ＣＴＵ、ＣＴＶ、ＣＴＷには一次導体貫通孔が設けられており、受電線の各相の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷが対応する変流器ＣＴＵ、ＣＴＶ、ＣＴＷの一次導体貫通孔を貫通している。各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの二次回路はＹ結線され、その中性線である残留回路ＲＣＣが地絡過電流継電器５１Ｇの入力側に接続されている。即ち、この残留回路ＲＣＣは、各相の変流器ＣＴＵ、ＣＴＶ，ＣＴＷの出力回路を共通に接続する共通回路に相当する。 In FIG. 1, power receiving cables ICU, ICV, and ICW for each phase of the power receiving wire correspond to the power receiving wire RL2 shown in FIG. The current transformers CTU, CTV, and CTW of each phase correspond to the current transformer CT provided in the receiving wire RL2 in FIG. The current transformers CTU, CTV, and CTW are provided with primary conductor through holes, and the primary conductor through holes of the current transformers CTU, CTV, and CTW corresponding to the power receiving cables ICU, ICV, and ICW of each phase of the power receiving wires are provided. It penetrates. The secondary circuits of the current transformers CTU, CTV, and CTW of each phase are Y-connected, and the residual circuit RCC that is a neutral line thereof is connected to the input side of the ground fault overcurrent relay 51G. That is, the residual circuit RCC corresponds to a common circuit that commonly connects the output circuits of the current transformers CTU, CTV, and CTW of the respective phases.

各相の接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷは、図２における接地開閉器ＥＳに対応する。そして、Ｕ相の接地開閉器ＥＳＵの接地側接点に接続されたＵ相の接地回路ＥＣＵと、Ｖ相の接地開閉器ＥＳＶの接地側接点に接続されたＶ相の接地回路ＥＣＶと、Ｗ相の接地開閉器ＥＳＷの接地側接点に接続されたＷ相の接地回路ＥＣＷとはＹ結線され、その中性線が接地抵抗ＲＥ（図１には図示していない）を介して接地される。なお、Ｕ相の接地回路ＥＣＵとＶ相の接地回路ＥＣＶとＷ相の接地回路ＥＣＷは、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの一次導体貫通孔を貫通していない。 The ground switch ESU, ESV, ESW of each phase corresponds to the ground switch ES in FIG. A U-phase ground circuit ECU connected to the ground-side contact of the U-phase ground switch ESU, a V-phase ground circuit ECV connected to the ground-side contact of the V-phase ground switch ESV, and a W-phase Is connected to the W-phase ground circuit ECW connected to the ground-side contact of the ground switch ESW, and its neutral line is grounded via a ground resistor RE (not shown in FIG. 1). Note that the U-phase ground circuit ECU, the V-phase ground circuit ECV, and the W-phase ground circuit ECW do not pass through the primary conductor through holes of the current transformers CTU, CTV, and CTW of each phase.

第１のスイッチ手段Ｃ１は、後述する図３に示す動作コイルＣＣ１と、この動作コイルＣＣ１が付勢されたとき閉じる３個のａ接点ＵａＣ１、ＶａＣ１、ＷａＣ１とを備える。これらの３個のａ接点ＵａＣ１、ＶａＣ１、ＷａＣ１は、夫々、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路に並列に接続されている。 The first switch means C1 includes an operating coil CC1 shown in FIG. 3, which will be described later, and three a contacts UaC1, VaC1, and WaC1 that close when the operating coil CC1 is energized. These three a contacts UaC1, VaC1, and WaC1 are respectively connected in parallel to the output circuits of the current transformers CTU, CTV, and CTW of each phase.

第２のスイッチ手段Ｃ２は、後述する図３に示す動作コイルＣＣ２と、この動作コイルＣＣ２が付勢されたとき開く４個のｂ接点ＵｂＣ２、ＶｂＣ２、ＷｂＣ２、ＲｂＣ２を備える。これらのｂ接点のうち、３個のｂ接点ＵｂＣ２、ＶｂＣ２、ＷｂＣ２は、夫々、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路に直列に接続され、他の１個のｂ接点ＲｂＣ２は、残留回路ＲＣＣに直列に接続されている。 The second switch means C2 includes an operating coil CC2 shown in FIG. 3 to be described later, and four b contacts UbC2, VbC2, WbC2, and RbC2 that open when the operating coil CC2 is energized. Of these b contacts, the three b contacts UbC2, VbC2, and WbC2 are connected in series to the output circuits of the current transformers CTU, CTV, and CTW of the respective phases, and the other one of the b contacts RbC2 is The residual circuit RCC is connected in series.

図３は、この発明の実施の形態１による保護継電器の誤動作防止装置における、第１のスイッチ手段及び第２のスイッチ手段の動作コイルの接続状態を示す説明図である。図３に於いて、前述の第１のスイッチ手段Ｃ１の動作コイルＣＣ１と、第２のスイッチ手段Ｃ２の動作コイルＣＣ２とは互いに並列接続され、第１の接地開閉器連動接点ＥＳＳ１と第２の接地開閉器連動接点ＥＳＳ２との並列接続体を介して、直流電源の正極ｐと負極ｎとの間に接続されている。 FIG. 3 is an explanatory diagram showing the connection state of the operating coils of the first switch means and the second switch means in the protection relay malfunction prevention device according to Embodiment 1 of the present invention. In FIG. 3, the operating coil CC1 of the first switch means C1 and the operating coil CC2 of the second switch means C2 are connected in parallel to each other so that the first ground switch interlocking contact ESS1 and the second switch It is connected between the positive electrode p and the negative electrode n of the DC power supply through a parallel connection body with the ground switch interlocking contact ESS2.

第１の接地開閉器連動接点ＥＳＳ１は、図２に示す受電線ＲＬ２に接続された接地開閉器ＥＳが接地側に切り換えられるとその動作に連動して閉じる接点であり、第２の接地開閉器連動接点ＥＳＳ２は、受電線ＲＬ２に接続された接地開閉器ＥＳが接地側に切り換えられる動作の途中に連動して閉じる接点である。第１の接地開閉器連動接点ＥＳＳ１と第２の接地開閉器連動接点ＥＳＳ２は、接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷの操作機構に、夫々前述のように連動して動作するように構成されている。 The first earthing switch interlocking contact ESS1 is a contact that closes in conjunction with the operation of the earthing switch ES connected to the receiving wire RL2 shown in FIG. The interlocking contact ESS2 is a contact that closes in conjunction with the operation of switching the grounding switch ES connected to the receiving wire RL2 to the grounding side. The first earthing switch interlocking contact ESS1 and the second earthing switch interlocking contact ESS2 are configured to operate in conjunction with the operation mechanisms of the earthing switches ESU, ESV, ESW, respectively, as described above. .

第１のスイッチ手段Ｃ１、及び第２のスイッチ手段Ｃ２は、全体としてこの発明の実施の形態１におけるスイッチ手段を構成する。 The first switch means C1 and the second switch means C2 constitute the switch means in the first embodiment of the present invention as a whole.

図４は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統の送電用鉄塔における、２回線の送電線の配置を示す説明図である。図４に示すように、停止回線Ｌ２である各相の送電線ｕ１、ｖ２、ｗ３、および運用回線Ｌ１である各相の送電線ｕ４、ｖ５、ｗ６が、互いに送電用鉄塔ＴＴの反対側に懸架されている。 FIG. 4 is an explanatory diagram showing the arrangement of two transmission lines in the transmission tower of the power system to which the protection relay malfunction prevention device according to Embodiment 1 of the present invention is applied. As shown in FIG. 4, the transmission lines u1, v2, and w3 of the phases that are the stop lines L2 and the transmission lines u4, v5, and w6 of the phases that are the operation lines L1 are on the opposite sides of the transmission tower TT. Suspended.

図５は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、運用回線と停止回線との電磁結合の視点での等価回路を示す説明図である。図５の等価回路に示すように、停止回線Ｌ２は運用回線Ｌ１に相互インダクタンスＭ［ｍＨ／ｍ］で電磁結合され、停止回線Ｌ２には誘導電圧Ｅ［Ｖ］が発生し、この誘導電圧Ｅ［Ｖ］による誘導電流が矢印のように流れる。なお、Ｒ［Ω／ｍ］、Ｌ［ｍＨ／ｍ］、およびＲＥ［Ω］は、夫々、停止回線Ｌ２の線路抵抗値、線路インダクタンス値、および接地抵抗値を示す。 FIG. 5 is an explanatory diagram showing an equivalent circuit from the viewpoint of electromagnetic coupling between the operation line and the stop line in the power system to which the malfunction prevention device for the protective relay according to Embodiment 1 of the present invention is applied. As shown in the equivalent circuit of FIG. 5, the stop line L2 is electromagnetically coupled to the operation line L1 with a mutual inductance M [mH / m], and an induced voltage E [V] is generated in the stop line L2. The induced current due to [V] flows as shown by an arrow. R [Ω / m], L [mH / m], and RE [Ω] indicate the line resistance value, line inductance value, and ground resistance value of the stop line L2, respectively.

図６は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、停止回線のＵ相送電線の相互リアクタンスを示す説明図、図７は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した電力系統における、停止回線のＶ相送電線の相互リアクタンスを示す説明図である。図６に示すように、停止回線Ｌ２のＵ相の送電線ｕ１の、他の相の送電線ｖ２、ｗ３、および運用回線Ｌ１の各相の送電線ｕ４、ｖ５、ｗ６との相互リアクタンスは、夫々、ｘ１２、ｘ１３、ｘ１４、ｘ１５、およびｘ１６となる。 FIG. 6 is an explanatory diagram showing the mutual reactance of the U-phase transmission line of the stop line in the power system to which the malfunction prevention device for the protective relay according to Embodiment 1 of the present invention is applied, and FIG. 7 is an embodiment of the present invention. It is explanatory drawing which shows the mutual reactance of the V-phase power transmission line of a stop line in the electric power system to which the malfunction prevention apparatus of the protection relay by 1 is applied. As shown in FIG. 6, the mutual reactance of the U-phase transmission line u1 of the stop line L2 with the transmission lines v2, w3 of the other phases and the transmission lines u4, v5, w6 of the respective phases of the operation line L1 is These are x12, x13, x14, x15, and x16, respectively.

一方、図７に示すように、停止回線Ｌ２のＶ相の送電線ｖ２の、他の相の送電線ｕ１、ｗ３、および運用回線Ｌ１の各相の送電線ｕ４、ｖ５、ｗ６との相互リアクタンスは、夫々、ｘ２１、ｘ２３、ｘ２４、ｘ２５、およびｘ２６となる。ここで、図５に示す相互インダクタンスと図６に示す相互インダクタンスは、各送電線の相互間距離の違いなどにより同じにならないことから、停止回線Ｌ２の各相の送電線ｕ１、ｖ２、ｗ３の各々に流れる誘導電流は同じ大きさにはならず、三相不平衡誘導電流が流れる。 On the other hand, as shown in FIG. 7, the mutual reactance of the V-phase transmission line v2 of the stop line L2 with the transmission lines u1, w3 of the other phases and the transmission lines u4, v5, w6 of the respective phases of the operation line L1. Are x21, x23, x24, x25, and x26, respectively. Here, the mutual inductance shown in FIG. 5 and the mutual inductance shown in FIG. 6 are not the same due to the difference in the distance between the transmission lines, etc., so the transmission lines u1, v2, and w3 of the respective phases of the stop line L2 The induced currents flowing through each do not have the same magnitude, and a three-phase unbalanced induced current flows.

図２に示すように、停止回線Ｌ２のオフ状態の遮断器ＣＢ２１に対応する接地開閉器ＥＳ、および受電線ＲＬ２のオフ状態の遮断器ＣＢ２２に対応する接地開閉器ＥＳは何れも安全上、接地側にオン状態にされているので、前述の三相不平衡誘導電流は、図２に矢印で示すように、停止回線Ｌ２−配電盤ＤＳＢ内の受電線ＲＬ２−配電盤ＤＳＢ内の受電線ＲＬ２に対応する接地開閉器ＥＳ−アース−停止回線Ｌ２の変電所Ｓ／Ｓ側の接地開閉器ＥＳ−停止回線Ｌ２の閉ループを還流する。 As shown in FIG. 2, the grounding switch ES corresponding to the circuit breaker CB21 in the off state of the stop line L2 and the grounding switch ES corresponding to the circuit breaker CB22 in the off state of the receiving line RL2 are both grounded for safety. The three-phase unbalanced induced current described above corresponds to the receiving line RL2 in the stop line L2-distribution panel DSB2, the receiving line RL2 in the distribution board DSB, as shown by the arrows in FIG. The closed circuit of the earthing switch ES-stop line L2 on the substation S / S side of the earthing switch ES-earth-stop line L2 to be returned is circulated.

次に、三相交流送電線を運用回線から停止回線に移行する場合に発生する対地静電容量からの放電電流について説明する。図８は、この発明の実施の形態１による保護継電器の誤動作防止装置を適用した別の電力系統の構成図である。図８に示す電力系統は、２回線送電システムとして構成されており、運用回線Ｌ１および停止回線Ｌ２を構成する送電線は、夫々、地中ケーブルとして配設されている。運用回線Ｌ１は、オン状態の遮断器ＣＢ１１を介して変電所Ｓ／Ｓから供給され、例えば２２［ｋＶ］で送電する。運用回線Ｌ１および停止回線Ｌ２と大地との間には対地静電容量Ｃが存在する。なお、図８では、停止回線Ｌ２が運用回線から停止回線へと切り換わった直後を示している。 Next, the discharge current from the ground capacitance that occurs when the three-phase AC transmission line is shifted from the operation line to the stop line will be described. FIG. 8 is a configuration diagram of another power system to which the protection relay malfunction prevention device according to Embodiment 1 of the present invention is applied. The power system shown in FIG. 8 is configured as a two-line power transmission system, and the power transmission lines constituting the operation line L1 and the stop line L2 are respectively arranged as underground cables. The operation line L1 is supplied from the substation S / S via the on-state circuit breaker CB11 and transmits power at, for example, 22 [kV]. A ground capacitance C exists between the operation line L1 and the stop line L2 and the ground. FIG. 8 shows a state immediately after the stop line L2 is switched from the active line to the stop line.

送電線の変電所Ｓ／Ｓ側端には、遮断器ＣＢ１１、ＣＢ２１が設けられ、これ等の遮断器ＣＢ１１またはＣＢ２１がオンとなることにより運用回線となり、遮断器ＣＢ１１又はＣＢ２１がオフとなることにより停止回線となる。図８では、遮断器ＣＢ１１がオン状態となりこれに接続されている送電線が運用回線Ｌ１であり、遮断器ＣＢ２１がオフ状態となりこれに接続されている送電線が停止回線Ｌ２となっている。 Circuit breakers CB11 and CB21 are provided at the substation S / S side end of the transmission line. When these circuit breakers CB11 or CB21 are turned on, the circuit breaker CB11 or CB21 is turned off. It becomes a stop line by. In FIG. 8, the circuit breaker CB11 is turned on and the power transmission line connected thereto is the operation line L1, and the circuit breaker CB21 is turned off and the power transmission line connected thereto is the stop line L2.

運用回線Ｌ１の遮断器ＣＢ１１近傍の負荷側には接地開閉器ＥＳが接続されている。この接地開閉器ＥＳは、遮断器ＣＢ１１がオンの状態ではオフであり、遮断器ＣＢ１１がオフの状態ではオンにされる。同様に停止回線Ｌ２の遮断器ＣＢ２１近傍の負荷側には接地開閉器ＥＳが接続されている。この接地開閉器ＥＳは、遮断器ＣＢ２１がオンの状態ではオフであり、遮断器ＣＢ２１がオフの状態ではオンにされる。図８では、前述したように停止回線Ｌ２が運用回線から停止回線へと切り換わった直後を表しているので、その接地開閉器ＥＳは接地側に切り換わる前の段階を例示している。 A ground switch ES is connected to the load side near the circuit breaker CB11 of the operation line L1. The ground switch ES is turned off when the circuit breaker CB11 is turned on, and is turned on when the circuit breaker CB11 is turned off. Similarly, a ground switch ES is connected to the load side near the circuit breaker CB21 of the stop line L2. The ground switch ES is turned off when the circuit breaker CB21 is turned on, and is turned on when the circuit breaker CB21 is turned off. Since FIG. 8 shows the state immediately after the stop line L2 is switched from the operation line to the stop line as described above, the ground switch ES illustrates the stage before switching to the ground side.

配電盤ＤＳＢ内にも２回線の受電線ＲＬ１、ＲＬ２が配設され、受電線ＲＬ１の負荷側端には遮断器ＣＢ１２が、受電線ＲＬ２の負荷側端には遮断器ＣＢ２２が、それぞれ設けられている。受電線ＲＬ１の受電端は運用回線Ｌ１に、受電線ＲＬ２の受電端は停止回線Ｌ２に、夫々接続されている。図８では、運用回線Ｌ１に接続された受電線ＲＬ１の遮断器ＣＢ１２はオン状態にあり、停止回線Ｌ２に接続された受電線ＲＬ２の遮断器ＣＢ２２はオフ状態にある場合を示している。 Two distribution lines RL1 and RL2 are also provided in the distribution board DSB. A circuit breaker CB12 is provided at the load side end of the reception line RL1, and a circuit breaker CB22 is provided at the load side end of the reception line RL2. Yes. The receiving end of the receiving line RL1 is connected to the operation line L1, and the receiving end of the receiving line RL2 is connected to the stop line L2. FIG. 8 shows a case where the breaker CB12 of the receiving line RL1 connected to the operation line L1 is in the on state, and the breaker CB22 of the receiving line RL2 connected to the stop line L2 is in the off state.

受電線ＲＬ１、ＲＬ２には、対応する遮断器ＣＢ１２、ＣＢ２２より受電端側に、夫々接地開閉器ＥＳが接続されている。また、図８では、当該接地開閉器ＥＳのうち遮断器ＣＢ１２に対応する接地開閉器ＥＳはオフに、遮断器ＣＢ２２に対応する接地開閉器ＥＳはオンに、夫々切り換わった瞬間を示している。 A ground switch ES is connected to each of the receiving wires RL1 and RL2 on the power receiving end side from the corresponding circuit breakers CB12 and CB22. FIG. 8 shows the moment when the ground switch ES corresponding to the circuit breaker CB12 is turned off and the ground switch ES corresponding to the circuit breaker CB22 is turned on. .

配電盤ＤＳＢ内の受電線ＲＬ１、ＲＬ２は、三相受電ケーブルにより構成されている。また、受電線ＲＬ１、ＲＬ２には、対応する接地開閉器ＥＳより受電端側に、夫々、地絡過電流継電器５１Ｇが夫々入力変流器ＣＴを介して接続され、回線単位で地絡過電流継電器５１Ｇにより運用回線を地絡から保護する構成としてある。受電線ＲＬ１、ＲＬ２対応の各遮断器ＣＢ１２、ＣＢ２２、受電線ＲＬ１、ＲＬ２に対応する接地開閉器ＥＳ、および地絡過電流継電器５１Ｇは、配電盤ＤＳＢ内に配設されている。負荷Ｌには、受電線ＲＬ１、ＲＬ２に遮断器ＣＢ１２、ＣＢ２２を介して接続された給電線ＦＬ１、ＦＬ２から変圧器Ｔｒ１、Ｔｒ２を介して給電される。 The receiving wires RL1 and RL2 in the distribution board DSB are constituted by three-phase receiving cables. In addition, a ground fault overcurrent relay 51G is connected to each of the receiving wires RL1 and RL2 from the corresponding ground switch ES to the power receiving end side via an input current transformer CT, and the ground fault overcurrent relay 51G is connected in units of lines. Therefore, the operation line is protected from the ground fault. The circuit breakers CB12 and CB22 corresponding to the receiving wires RL1 and RL2, the grounding switch ES corresponding to the receiving wires RL1 and RL2, and the ground fault overcurrent relay 51G are arranged in the switchboard DSB. Power is supplied to the load L from the feeder lines FL1 and FL2 connected to the receiving lines RL1 and RL2 via the circuit breakers CB12 and CB22 via the transformers Tr1 and Tr2.

図９は、図８に示す電力系統における、対地静電容量を通して流れる充電電流を示す説明図、図１０は、図８に示す電力系統における、対地静電容量に充電される電荷を示す説明図、図１１は、図８に示す電力系統における、対地静電容量から流れる放電電流を示す説明図である。図９乃至図１１では、送電線が運用回線から停止回線へと移行する段階を例示している。 9 is an explanatory diagram showing the charging current flowing through the ground capacitance in the power system shown in FIG. 8, and FIG. 10 is an explanatory diagram showing the charge charged in the ground capacitance in the power system shown in FIG. FIG. 11 is an explanatory diagram showing a discharge current flowing from the ground capacitance in the power system shown in FIG. 9 to 11 exemplify a stage where the power transmission line shifts from the operation line to the stop line.

図９に示すように、運用回線とされていた送電線Ｌ２を停止回線に移行するため、送電線Ｌ２に接続された受電線ＲＬ２の遮断器ＣＢ２２を開放する。送電線Ｌ２の変電所Ｓ／Ｓ側端の遮断器ＣＢ２１は受電線ＲＬ２の遮断器ＣＢ２２より後に開放されるため、変電所Ｓ／Ｓ側から対地静電容量Ｃを通して充電電流が流れる。なお、ここでは、移行後に停止回線Ｌ２となる送電線を説明の便宜上、送電線Ｌ２と称している。 As shown in FIG. 9, in order to transfer the power transmission line L2 that has been the operation line to the stop line, the circuit breaker CB22 of the receiving line RL2 connected to the power transmission line L2 is opened. Since the circuit breaker CB21 at the substation S / S side end of the transmission line L2 is opened after the circuit breaker CB22 of the receiving line RL2, a charging current flows from the substation S / S side through the ground capacitance C. Here, the power transmission line that becomes the stop line L2 after the transition is referred to as a power transmission line L2 for convenience of explanation.

次に、図１０では受電線ＲＬ２の遮断器ＣＢ２２を開放した後に、送電線Ｌ２の変電所Ｓ／Ｓ側端の遮断器ＣＢ２１を開放した状態を示している。この場合、変電所Ｓ／Ｓ側から対地静電容量Ｃを通して流れていた充電電流が遮断器ＣＢ２１の解放により遮断されるため、対地静電容量Ｃは充電された状態を維持する。また遮断器ＣＢ２１の裁断電流の大きさにより各相の充電電流を裁断するタイミングが異なるため、各相の対地静電容量Ｃに充電される電荷の量は三相不平衡の状態となる。 Next, FIG. 10 shows a state in which the breaker CB21 at the substation S / S side end of the transmission line L2 is opened after the breaker CB22 of the receiving wire RL2 is opened. In this case, since the charging current flowing from the substation S / S side through the ground capacitance C is interrupted by the release of the circuit breaker CB21, the ground capacitance C is maintained in a charged state. In addition, since the timing of cutting the charging current of each phase varies depending on the magnitude of the cutting current of the circuit breaker CB21, the amount of charge charged to the ground capacitance C of each phase is in a three-phase unbalanced state.

ここで、安全のため送電線Ｌ２に接続された受電線ＲＬ２の接地開閉器ＥＳと送電線Ｌ２の変電所Ｓ／Ｓ側端の接地開閉器ＥＳを接地側に切り換えるが、受電線ＲＬ２の接地開閉器ＥＳが送電線Ｌ２の変電所Ｓ／Ｓ側端の接地開閉器ＥＳが先に接地側に切り換わった場合、図１１に矢印で示す放電電流が、対地静電容量Ｃ−送電線Ｌ２−配電盤ＤＳＢ内の受電線ＲＬ２−配電盤ＤＳＢ内の受電線ＲＬ２に対応する接地開閉器ＥＳ−アースの方向に向かい流れる。前述したように対地静電容量に充電される電荷の量は三相不平衡の状態となるため、充電される電荷の量に基づく放電電流の大きさも三相不平衡の状態となる。 Here, for safety, the grounding switch ES of the receiving line RL2 connected to the transmission line L2 and the grounding switch ES at the substation S / S side end of the transmission line L2 are switched to the ground side, but the grounding of the receiving line RL2 is performed. When the ground switch ES at the substation S / S side end of the transmission line L2 is first switched to the ground side, the discharge current indicated by the arrow in FIG. -It flows in the direction of the earthing switch ES corresponding to the receiving wire RL2 in the switchboard DSB2-the receiving wire RL2 in the switchboard DSB. As described above, since the amount of charge charged to the ground capacitance is in a three-phase unbalanced state, the magnitude of the discharge current based on the amount of charged charge is also in a three-phase unbalanced state.

つまり、図１のように、Ｕ相の受電ケーブルＩＣＵを一次導体とする変流器ＣＴＵの出力電流ｉｕと、Ｖ相の受電ケーブルＩＣＶを一次導体とする変流器ＣＴＶの出力電流ｉｖと、Ｗ相の受電ケーブルＩＣＷを一次導体とする変流器ＣＴＷの出力電流ｉｗとが、三相不平衡の状態となり、例えばそれらの方向は図示矢印のように出力電流ｉｕ、ｉｖ、ｉｗが同方向となり、それらの合成電流の大きさ［ｉｕ＋ｉｖ＋ｉｗ］は「０」とならず、合成電流［ｉｕ＋ｉｖ＋ｉｗ］が残留回路ＲＣＣに接続された地絡過電流継電器５１の動作電流として流れ、当該合成電流が地絡過電流継電器５１Ｇの動作値を超える場合は、地絡過電流継電器５１Ｇは動作することになる。即ち、保護継電器５１Ｇは地絡事故電流以外の電流により誤動作することになる。 That is, as shown in FIG. 1, the output current iu of the current transformer CTU using the U-phase power receiving cable ICU as the primary conductor, the output current iv of the current transformer CTV using the V-phase power receiving cable ICV as the primary conductor, The output current iw of the current transformer CTW having the W-phase power receiving cable ICW as the primary conductor is in a three-phase unbalanced state, and the directions of the output currents iu, iv, iw are in the same direction as indicated by arrows in the figure, for example. Thus, the magnitude [iu + iv + iw] of these combined currents does not become “0”, and the combined current [iu + iv + iw] flows as the operating current of the ground fault overcurrent relay 51 connected to the residual circuit RCC, and the combined current is When the operating value of the current relay 51G is exceeded, the ground fault overcurrent relay 51G operates. That is, the protective relay 51G malfunctions due to a current other than the ground fault current.

しかし、この発明の実施の形態１による保護継電器の誤動作防止装置は、前述の第１のスイッチ手段Ｃ１、および第２のスイッチ手段Ｃ２により、三相不平衡状態の誘導電流や放電電流による地絡過電流継電器の誤動作が、以下述べるように防止される。 However, the malfunction prevention device for the protective relay according to the first embodiment of the present invention uses the first switch means C1 and the second switch means C2 described above to cause a ground fault excess due to an induced current or a discharge current in a three-phase unbalanced state. A malfunction of the current relay is prevented as described below.

即ち、図１乃至図３に於いて、今、送電線Ｌ２が運用回線から停止回線に切り換えられたとすると、前述のように受電線ＲＬ２に接続された接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷは接地側に切り換えられるが、その切り換え操作の途中の段階に於いて第２の接地開閉器連動接点ＥＳＳ２はオンとなる。また、接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷの切り換え操作が完了して接地側に切り換えられると、第１の接地開閉器連動接点ＥＳＳ１がオンとなる。その結果、接地開閉器ＥＳＵ、ＥＳＶ、ＥＳＷが接地側へ切り換えられる操作中の段階から接地完了以降に至り、第１のスイッチ手段Ｃ１の各ａ接点ＵａＣ１、ＶａＣ１、ＷａＣ１はオンとなり、第２のスイッチ手段Ｃ２の各ｂ接点ＵｂＣ２、ＶｂＣ２、ＷｂＣ２、ＲｂＣ２はオフとなる。 That is, in FIGS. 1 to 3, if the transmission line L2 is switched from the operation line to the stop line, the ground switches ESU, ESV, ESW connected to the receiving line RL2 as described above are connected to the ground side. However, in the middle of the switching operation, the second earthing switch interlocking contact ESS2 is turned on. When the switching operation of the ground switches ESU, ESV, ESW is completed and switched to the ground side, the first ground switch interlocking contact ESS1 is turned on. As a result, from the stage in which the earthing switches ESU, ESV, ESW are switched to the ground side and after the earthing is completed, the a contacts UaC1, VaC1, WaC1 of the first switch means C1 are turned on, and the second The b contacts UbC2, VbC2, WbC2, and RbC2 of the switch means C2 are turned off.

これにより、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路が遮断されると同時にその残留回路ＲＣＣが遮断され、且つ各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路が三相短絡される。その結果、停止回線Ｌ２における誘導電流及び放電電流に基づく三相不平衡電流による地絡過電流継電器５１Ｇの誤動作は確実に防止されるものである。 As a result, the output circuits of the current transformers CTU, CTV, CTW of each phase are shut off, and at the same time, the residual circuit RCC is shut off, and the output circuits of the current transformers CTU, CTV, CTW of each phase are short-circuited. Is done. As a result, the malfunction of the ground fault overcurrent relay 51G due to the three-phase unbalanced current based on the induced current and the discharge current in the stop line L2 is surely prevented.

実施の形態２．
図１２は、この発明の実施の形態２による保護継電器の誤動作防止装置を示す構成図である。図１２に於いて、保護継電器としての過電流保護継電器５１が、変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路に夫々設けられている。この過電流保護継電器５１は、運用回線に接続された受電線の受電ケーブルＩＣＵ、ＩＣＶ、ＩＣＷに、所定値以上の過電流が流れた場合に動作する保護継電器である。その他の構成は、前述の実施の形態１の場合と同様である。 Embodiment 2. FIG.
FIG. 12 is a block diagram showing a malfunction prevention device for a protective relay according to Embodiment 2 of the present invention. In FIG. 12, an overcurrent protection relay 51 as a protection relay is provided in the output circuit of each of the current transformers CTU, CTV, and CTW. The overcurrent protection relay 51 is a protection relay that operates when an overcurrent of a predetermined value or more flows through the receiving cables ICU, ICV, and ICW of the receiving lines connected to the operation line. Other configurations are the same as those in the first embodiment.

このように構成された実施の形態２による保護継電器の誤動作防止装置に於いて、三相不平衡状態の誘導電流や放電電流が受電線に流れた場合、前述の実施の形態１の場合と同様に、停止回線Ｌ２における誘導電流及び放電電流に基づく三相不平衡電流による地絡過電流継電器５１Ｇの誤動作は確実に防止される。また、過電流保護継電器５１も、前述と同様に、第１のスイッチ手段Ｃ１及び第２のスイッチ手段Ｃ２により、各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路が遮断されると同時にその残留回路ＲＣＣが遮断され、且つ各相の変流器ＣＴＵ、ＣＴＶ、ＣＴＷの出力回路が三相短絡されることにより、前述の誘導電流や放電電流による誤動作が確実に防止されるものである。 In the protection relay malfunction prevention device according to the second embodiment configured as described above, when an induced current or a discharge current in a three-phase unbalanced state flows through the receiving wire, the same as in the first embodiment described above. In addition, the malfunction of the ground fault overcurrent relay 51G due to the three-phase unbalanced current based on the induced current and the discharge current in the stop line L2 is reliably prevented. Further, the overcurrent protection relay 51 also has its output circuit of the current transformers CTU, CTV, CTW of each phase cut off by the first switch means C1 and the second switch means C2 at the same time as described above. The residual circuit RCC is cut off, and the output circuits of the current transformers CTU, CTV, and CTW of the respective phases are short-circuited by three phases, thereby reliably preventing the malfunction caused by the above-described induced current and discharge current.

ＣＢ１１、ＣＢ１２、ＣＢ２１、ＣＢ２２遮断器
ＣＴ、ＣＴＵ、ＣＴＶ、ＣＴＷ変流器
ＲＥ接地抵抗
ＤＳＢ配電盤、
ＥＣＵ、ＥＣＶ、ＥＣＷ接地回路
ＥＳ、ＥＳＵ、ＥＳＶ、ＥＳＷ接地開閉器、
ＲＬ１、ＲＬ２受電線
ＩＣＵ、ＩＣＶ、ＩＣＷ受電ケーブル
ＦＬ１、ＦＬ２給電線
Ｌ負荷
Ｌ１運用回線
Ｌ２停止回線
ＲＣＣ残留回路
Ｃ１第１のスイッチ手段
ＵａＣ１、ＶａＣ１、ＷａＣ１第１のスイッチ手段のａ接点
Ｃ２第２のスイッチ手段
ＵｂＣ２、ＶｂＣ２、ＷｂＣ２第２のスイッチ手段のｂ接点
ＣＣ１第１のスイッチ手段の動作コイル
ＣＣ２第２のスイッチ手段の動作コイル
ＥＳＳ１第１の接地開閉器連動接点
ＥＳＳ２第２の接地開閉器連動接点
Ｓ／Ｓ変電所
Ｔｒ１、Ｔｒ２変圧器、
ＴＴ鉄塔
ｕ１、ｖ２、ｗ３、ｕ４、ｖ５、ｗ６送電線
５１過電流保護継電器
５１Ｇ地絡過電流継電器 CB11, CB12, CB21, CB22 Circuit breaker CT, CTU, CTV, CTW Current transformer RE Ground resistance DSB Switchboard,
ECU, ECV, ECW Grounding circuit ES, ESU, ESV, ESW Grounding switch,
RL1, RL2 Receiving line ICU, ICV, ICW Receiving cable FL1, FL2 Feed line L Load L1 Operation line L2 Stop line RCC Residual circuit C1 First switch means UaC1, VaC1, WaC1 First contact means a contact C2 Second Switch means UbC2, VbC2, WbC2 b switch CC1 of the second switch means operating coil CC2 of the first switch means operating coil ESS1 of the second switch means first ground switch interlocking contact ESS2 second ground switch Interlocking contact S / S Substation Tr1, Tr2 Transformer,
TT steel tower u1, v2, w3, u4, v5, w6 Transmission line 51 Overcurrent protection relay 51G Ground fault overcurrent relay

Claims

三相交流電路の各相の電路を夫々一次導体とする複数個の変流器の出力回路に共通接続された共通回路に流れる電流に基づいて動作する保護継電器に対する誤動作防止装置であって、
前記各相の電路は、送電停止時に接地開閉器を介して接地されるように構成されており、
前記接地開閉器が前記接地を行う動作に基づいて駆動され、前記複数個の変流器の出力回路を短絡すると共に前記複数個の変流器の夫々の出力回路と前記共通回路とのうちの少なくとも一方を遮断するスイッチ手段を備えた、
ことを特徴とする保護継電器の誤動作防止装置。 A malfunction prevention device for a protective relay that operates based on a current that flows in a common circuit that is commonly connected to an output circuit of a plurality of current transformers each having a primary conductor for each phase of the three-phase AC circuit,
The electric circuit of each phase is configured to be grounded via a ground switch when power transmission is stopped,
The ground switch is driven based on the grounding operation, and short-circuits the output circuits of the plurality of current transformers, and includes the output circuit of each of the plurality of current transformers and the common circuit. Provided with switch means for shutting off at least one,
A device for preventing malfunction of a protective relay.

前記スイッチ手段は、前記接地開閉器の前記動作の少なくとも途中に於いて前記駆動されることを特徴とする請求項１に記載の保護継電器の誤動作防止装置。 2. The protective relay malfunction prevention device according to claim 1, wherein the switch means is driven at least during the operation of the ground switch.

前記スイッチ手段は、
前記接地開閉器が前記接地を行う動作に基づいて動作し、前記複数個の変流器の出力回路を夫々短絡する第１のスイッチ手段と、
前記接地開閉器が前記接地を行う動作に基づいて動作し、複数個の変流器の出力回路を夫々遮断すると共に前記共通回路を遮断する第２のスイッチ手段と、
により構成されていることを特徴とする請求項１又は２に記載の保護継電器の誤動作防止装置。 The switch means includes
A first switch means for operating the grounding switch based on the grounding operation and short-circuiting the output circuits of the plurality of current transformers;
A second switch means for operating the ground switch based on the operation of performing the grounding, shutting off the output circuits of a plurality of current transformers and shutting off the common circuit;
The apparatus for preventing malfunction of a protective relay according to claim 1 or 2, characterized by comprising:

三相交流電路の各相の電路を夫々一次導体とする複数個の変流器の出力回路を共通に接続した共通回路に流れる電流に基づいて動作する保護継電器に対する誤動作防止装置であって、
前記各相の電路は、送電停止時に接地開閉器を介して接地されるように構成されており、
前記接地開閉器が前記接地を行う動作の途中に連動して閉じる第１の接地開閉器連動接点と、
前記接地開閉器が前記接地を行う動作の完了に連動して閉じる第２の接地開閉器連動接点と、
前記第１の接地開閉器連動接点と前記第２の接地開閉器連動接点とのうちの少なくとも一方が閉じたときに動作し、前記複数個の変流器の夫々の出力回路を短絡すると共に前記複数個の変流器の夫々の出力回路と前記共通回路とのうちの少なくとも一方を遮断するスイッチ手段と、
を備えたことを特徴とする保護継電器の誤動作防止装置。 A malfunction prevention device for a protective relay that operates based on a current flowing through a common circuit in which output circuits of a plurality of current transformers each having a primary conductor as an electric circuit of each phase of a three-phase AC circuit are connected,
The electric circuit of each phase is configured to be grounded via a ground switch when power transmission is stopped,
A first earthing switch interlocking contact that closes in the middle of the operation of the earthing switch performing the earthing;
A second earthing switch interlocking contact that closes in conjunction with completion of the operation of the earthing switch performing the earthing;
It operates when at least one of the first earthing switch interlocking contact and the second earthing switch interlocking contact is closed, short-circuits the output circuit of each of the plurality of current transformers, and Switch means for cutting off at least one of the output circuit of each of the plurality of current transformers and the common circuit;
An apparatus for preventing malfunction of a protective relay, comprising:

前記スイッチ手段は、
前記第１の接地開閉器連動接点と前記第２の接地開閉器連動接点とのうちの少なくとも一方が閉じたときに動作して、前記複数個の変流器の夫々の出力回路を短絡する第１のスイッチ手段と、
前記第１の接地開閉器連動接点と前記第２の接地開閉器連動接点とのうちの少なくとも一方が閉じたときに動作して、前記複数個の変流器の夫々の出力回路を遮断すると共に前記共通回路を遮断する第２のスイッチ手段と、
により構成されていることを特徴とする請求項４に記載の保護継電器の誤動作防止装置。 The switch means includes
A first circuit that operates when at least one of the first earthing switch interlocking contact and the second earthing switch interlocking contact is closed to short-circuit each output circuit of the plurality of current transformers. A switch means,
It operates when at least one of the first grounding switch interlocking contact and the second grounding switch interlocking contact is closed to shut off the output circuit of each of the plurality of current transformers. Second switch means for interrupting the common circuit;
The malfunction prevention device for a protective relay according to claim 4, wherein the malfunction prevention device is configured as follows.

前記第１のスイッチ手段は、ａ接点により構成され、
前記第２のスイッチ手段は、ｂ接点により構成されている、
ことを特徴とする請求項３又は５に記載の保護継電器の誤動作防止装置。 The first switch means includes an a contact,
The second switch means is constituted by a b contact,
The malfunction prevention device of the protective relay according to claim 3 or 5, characterized in that.

前記三相交流電路は、三相の受電線によりにより構成され、
前記受電線の少なくとも一部と、前記複数個の変流器と、前記接地開閉器とが同一の配電盤内に収納されていることを特徴とする請求項１乃至６のうちの何れか一項に記載の保護継電器の誤動作防止装置。 The three-phase AC circuit is constituted by a three-phase power receiving line,
The at least part of the said receiving wire, these current transformers, and the said earthing switch are accommodated in the same switchboard, The any one of Claim 1 thru | or 6 characterized by the above-mentioned. The malfunction prevention device of the protective relay described in 1.

前記保護継電器と前記スイッチ手段は、前記配電盤内に収納されていることを特徴とする請求項７に記載の保護継電器の誤動作防止装置。 The apparatus for preventing malfunction of a protective relay according to claim 7, wherein the protective relay and the switch means are accommodated in the switchboard.

前記保護継電器は、地絡過電流継電器により構成され、
前記複数個の変流器の出力回路の夫々に、過電流継電器からなる保護継電器が接続されており、
前記地絡過電流継電器からなる保護継電器及び前記過電流継電器からなる保護継電器の誤動作を、夫々防止することを特徴とする請求項１乃至８のうちの何れか一項に記載の保護継電器の誤動作防止装置。
The protective relay is constituted by a ground fault overcurrent relay,
A protective relay made of an overcurrent relay is connected to each of the output circuits of the plurality of current transformers,
The malfunction prevention of the protective relay according to any one of claims 1 to 8, wherein malfunctions of the protective relay composed of the ground fault overcurrent relay and the protective relay composed of the overcurrent relay are respectively prevented. apparatus.