JP2009254036A

JP2009254036A - Ground fault protecting relay system

Info

Publication number: JP2009254036A
Application number: JP2008095879A
Authority: JP
Inventors: Shigeo Matsumoto; 重穗松本; Yoshiaki Date; 義明伊達; Masami Takenaka; 正実竹中
Original assignee: Chugoku Electric Power Co Inc
Current assignee: Chugoku Electric Power Co Inc
Priority date: 2008-04-02
Filing date: 2008-04-02
Publication date: 2009-10-29

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground fault protecting relay system capable of protecting a parallel two-line transmission line against a ground fault without causing deterioration in the degree of reliability of supply. <P>SOLUTION: When a ground fault breaking out in a first transmission power 1L direction is detected in a first transmission terminal ground fault relay device 21<SB>1</SB>and the ground fault is further detected in a power transmission end ground fault overcurrent relay device 11, a first ground fault current relay device trip signal T<SB>OCG1</SB>is output to a first breaker 4<SB>1</SB>, and when a ground fault breaking out in a second transmission line 2L direction is detected by a second transmission end ground fault direction relay device 21<SB>2</SB>, and the ground fault is further detected by the transmission end ground fault overcurrent relay device 11, a second ground fault overcurrent relay device trip signal T<SB>OCG2</SB>is output to a second breaker 4<SB>2</SB>. A power reception end ground fault overcurrent relay device 12, and first and second power reception end ground fault direction relay devices 22<SB>1</SB>, 22<SB>2</SB>operate similarly to the power transmission end ground fault overcurrent relay device 11 and the first and second power transmission end ground fault direction relay devices 21<SB>1</SB>, 21<SB>2</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、地絡保護継電システムに関し、特に、平衡２回線送電線を地絡事故から保護するのに好適な地絡保護継電システムに関する。 The present invention relates to a ground fault protection relay system, and more particularly to a ground fault protection relay system suitable for protecting a balanced two-line transmission line from a ground fault.

従来、抵抗接地型平衡２回線送電線のローカル系統での地絡保護は、図１０に示す地絡保護継電システムのように、主保護として地絡回線選択継電装置（送電端地絡回線選択継電装置１１１と受電端地絡回線選択継電装置１１２）を使用するとともに、後備保護として地絡方向継電装置（第１および第２の地絡方向継電装置１２１₁，１２１₂と第１および第２の受電端地絡方向継電装置１２２₁，１２２₂）を使用して行われている（下記の特許文献１など参照）。 Conventionally, the ground fault protection in the local system of the resistance ground type balanced two-line transmission line is the main protection like the ground fault protection relay system shown in FIG. While using the selective relay device 111 and the power receiving terminal ground fault line selective relay device 112), as a back-up protection, the ground fault direction relay devices (first and second ground fault direction relay devices 121 ₁ , 121 ₂ and The first and second power receiving end ground fault direction relay devices 122 ₁ , 122 ₂ ) are used (see, for example, Patent Document 1 below).

なお、下記の特許文献２には、線路零相電流と中性点零相電流との比が１／Ｗ（回線数）よりも大きいか否かを判定し、線路零相電流と中性点零相電流との比が１／Ｗよりも大きい場合には地絡事故発生と判定して遮断信号を遮断器に供給することにより、線路零相電流と中性点零相電流との比は事故点抵抗値を含まないので、事故点抵抗値に影響されず確実に地絡事故を検出するようにした地絡回線選択保護継電装置が開示されている。
特開平１１−６９６０８号公報特開平５−３２８５８８号公報 In Patent Document 2 below, it is determined whether or not the ratio between the line zero-phase current and the neutral point zero-phase current is greater than 1 / W (number of lines). When the ratio of the zero-phase current is larger than 1 / W, it is determined that a ground fault has occurred, and the interrupt signal is supplied to the circuit breaker, so that the ratio of the line zero-phase current and the neutral zero-phase current is Since the fault point resistance value is not included, there has been disclosed a ground fault line selection protection relay device that reliably detects a ground fault without being affected by the fault point resistance value.
Japanese Patent Laid-Open No. 11-69608 JP-A-5-328588

しかしながら、図１０に示した地絡保護継電システムでは、以下に示すように零相循環電流による送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２の誤動作に起因する供給信頼度の低下という問題があった。
主保護として使用されている送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２は保護区間（送電端母線と受電端母線との間の区間）の５０％地点（線路中間点）での故障時の最小零相電流（保護区間の３０％相当の不完全零相電流）で動作するように整定されている。
たとえば、系統内最小ＮＧＲ容量＝１５０Ａ時の整定とすると、送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２に入力される電流の値は（１５０×０．３）／２＝２２．５（Ａ）になるため、送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２の整定値は２２．５Ａとされる。
このため、零相循環電流が１１．２５Ａ以上流れると、リレー入力の零相電流（差接続された第１および第２の零相変流器３₁，３₂から送電端地絡回線選択継電装置１１１に入力される零相電流と、差接続された第３および第４の零相変流器３₃，３₄から受電端地絡回線選択継電装置１１２に入力される零相電流）は零相循環電流の２倍（２２．５Ａ以上）になって整定値以上になるため、送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２が誤動作してしまい、供給信頼度の低下を招いている。
なお、零相循環電流により誤動作しないように送電端地絡回線選択継電装置１１１および受電端地絡回線選択継電装置１１２を整定した場合には、保護範囲が狭まって無保護区間が生じる。また、零相循環電流対策付きの地絡回線選択継電装置（たとえば、差回路に流れる事故時の零相電流の有効分と事故前の零相電流の有効分との差分を求めることにより零相循環電流の影響を除去して動作量を算出する変化分検出器（変化幅形）地絡回線選択継電装置や、リレー入力の零相電流から零相循環電流分を除去するように補償をかける補償形地絡回線選択継電装置）を使用した場合には、コスト増になる。 However, in the ground fault protection relay system shown in FIG. 10, it is caused by a malfunction of the power transmission terminal ground fault line selection relay device 111 and the power receiving terminal ground fault line selection relay device 112 due to the zero-phase circulating current as shown below. There was a problem that the supply reliability decreased.
The power transmission terminal ground fault line selection relay device 111 and the power reception terminal ground fault line selection relay device 112 used as the main protection are 50% of the protection section (the section between the power transmission terminal bus and the power reception terminal bus) ( It is set so as to operate with a minimum zero-phase current at the time of a failure at the line intermediate point (an incomplete zero-phase current corresponding to 30% of the protection interval).
For example, assuming that the minimum NGR capacity in the system is 150 A, the value of the current input to the power transmission terminal ground fault line selection relay device 111 and the power reception terminal ground fault line selection relay device 112 is (150 × 0.3). ) /2=22.5 (A), the setting values of the power transmission terminal ground fault line selection relay device 111 and the power reception terminal ground fault line selection relay device 112 are 22.5 A.
For this reason, if the zero-phase circulating current flows over 11.25 A, the relay input zero-phase current (the first and second zero-phase current transformers 3 ₁ and 3 ₂ connected to each other from the differentially connected power transmission terminal ground fault line selection relay) Zero-phase current input to the electric device 111 and zero-phase current input from the third and fourth zero-phase current transformers 3 ₃ and 3 _{4 connected} to each other to the power receiving terminal ground fault line selection relay device 112 ) Becomes twice the zero-phase circulating current (22.5A or more) and exceeds the set value, so that the power transmission terminal ground fault line selection relay device 111 and the power reception terminal ground fault line selection relay device 112 malfunction. As a result, the supply reliability is lowered.
In addition, when the power transmission terminal ground fault line selection relay device 111 and the power reception terminal ground fault line selection relay device 112 are set so as not to malfunction due to the zero-phase circulating current, the protection range is narrowed and an unprotected section is generated. In addition, a ground fault line selection relay device with a zero-phase circulating current countermeasure (for example, zero by calculating the difference between the effective amount of the zero-phase current at the time of the accident flowing through the difference circuit and the effective component of the zero-phase current before the accident) Change detector (variation width type) ground fault line selection relay that eliminates the effect of phase circulating current and calculates the amount of operation, and compensates to remove zero phase circulating current from relay input zero phase current When a compensation type ground fault line selection relay device is applied, the cost increases.

本発明の目的は、供給信頼度の低下を招くことなく平衡２回線送電線を地絡事故から保護することができる地絡保護継電システムを提供することにある。 An object of the present invention is to provide a ground fault protection relay system capable of protecting a balanced two-line transmission line from a ground fault without causing a decrease in supply reliability.

本発明の地絡保護継電システムは、平衡２回線送電線を地絡事故から保護するための地絡保護継電システムであって、前記平衡２回線送電線に設置された、かつ、該平衡２回線送電線の第１および第２の送電線（１Ｌ，２Ｌ）をそれぞれ流れる零相電流の差電流に基づいて動作する地絡過電流継電装置（１１；１２）と、前記第１および第２の送電線にそれぞれ設置された第１および第２の地絡方向継電装置（２１₁，２１₂；２２₁，２２₂）とを具備し、前記第１の地絡方向継電装置において前記第１の送電線方向で発生した地絡事故を検出するとともに前記地絡過電流継電装置においても該地絡事故を検出すると、該第１の送電線に設置された遮断器（４₁，４₃）を遮断するためのトリップ信号を出力し、前記第２の地絡方向継電装置において前記第２の送電線方向で発生した地絡事故を検出するとともに前記地絡過電流継電装置においても該地絡事故を検出すると、該第２の送電線に設置された他の遮断器（４₂，４₄）を遮断するための他のトリップ信号を出力することを特徴とする。
また、本発明の地絡保護継電システムは、平衡２回線送電線を地絡事故から保護するための地絡保護継電システムであって、前記平衡２回線送電線の送電端に設置された送電端地絡過電流継電装置（１１）と第１および第２の送電端地絡方向継電装置（２１₁，２１₂）とを具備し、前記第１の送電端地絡方向継電装置が、前記平衡２回線送電線の第１の送電線（１Ｌ）方向において地絡事故が発生したことを検出すると第１の事故回線判定結果信号（Ｓ₁）を前記送電端地絡過電流継電装置に出力する第１のリレー判定手段（３１）を備え、前記第２の送電端地絡方向継電装置が、前記平衡２回線送電線の第２の送電線（２Ｌ）方向において地絡事故が発生したことを検出すると第２の事故回線判定結果信号（Ｓ₂）を前記送電端地絡過電流継電装置に出力する第２のリレー判定手段（４１）を備え、前記送電端地絡過電流継電装置が、前記第１の送電線の送電端を流れる第１の零相電流（Ｉ₀₁）および前記第２の送電線の送電端を流れる第２の零相電流（Ｉ₀₂）の差電流（Ｉ₀₁−Ｉ₀₂）に基づいて該第１または第２の送電線における地絡事故の発生を検出する地絡事故検出手段（５１）と、該地絡事故検出手段において地絡事故の発生を検出するとともに前記第１の送電端地絡方向継電装置から前記第１の事故回線判定結果信号が入力されると、該第１の送電線の送電端に設置された第１の遮断器（４₁）を遮断するための第１の地絡過電流継電装置トリップ信号（Ｔ_OCG1）を発生する第１の地絡過電流継電装置トリップ信号発生手段（５３₁）と、前記地絡事故検出手段において地絡事故の発生を検出するとともに前記第２の送電端地絡方向継電装置から前記第２の事故回線判定結果信号が入力されると、該第２の送電線の送電端に設置された第２の遮断器（４₂）を遮断するための第２の地絡過電流継電装置トリップ信号（Ｔ_OCG2）を発生する第２の地絡過電流継電装置トリップ信号発生手段（５３₂）とを備えることを特徴とする。
ここで、前記平衡２回線送電線の受電端に設置された受電端地絡過電流継電装置（１２）と第１および第２の受電端地絡方向継電装置（２２₁，２２₂）とをさらに具備し、前記第１の受電端地絡方向継電装置が、前記第１の送電線方向において地絡事故が発生したことを検出すると第３の事故回線判定結果信号（Ｓ₃）を前記受電端地絡過電流継電装置に出力する第３のリレー判定手段（６１）を備え、前記第２の受電端地絡方向継電装置が、前記第２の送電線方向において地絡事故が発生したことを検出すると第４の事故回線判定結果信号（Ｓ₄）を前記受電端地絡過電流継電装置に出力する第４のリレー判定手段（７１）を備え、前記受電端地絡過電流継電装置が、前記第１の送電線の受電端を流れる第３の零相地絡電流（Ｉ₀₃）および前記第２の送電線の受電端を流れる第４の零相地絡電流（Ｉ₀₄）の差電流（Ｉ₀₃−Ｉ₀₄）に基づいて該第１または第２の送電線における地絡事故の発生を検出する他の地絡事故検出手段（８１）と、該他の地絡事故検出手段において地絡事故の発生を検出するとともに前記第１の受電端地絡方向継電装置から前記第３の事故回線判定結果信号が入力されると、該第１の送電線の受電端に設置された第３の遮断器（４₃）を遮断するための第３の地絡過電流継電装置トリップ信号（Ｔ_OCG3）を発生する第３の地絡過電流継電装置トリップ信号発生手段（８３₁）と、前記地絡事故検出手段において地絡事故の発生を検出するとともに前記第２の受電端地絡方向継電装置から前記第４の事故回線判定結果信号が入力されると、該第２の送電線の受電端に設置された第４の遮断器（４₄）を遮断するための第４の地絡過電流継電装置トリップ信号（Ｔ_OCG4）を発生する第４の地絡過電流継電装置トリップ信号発生手段（８３₂）とを備えてもよい。
前記送電端地絡過電流継電装置が、前記第１および第２の遮断器が遮断されていないことを条件に前記第１および第２の地絡過電流継電装置トリップ信号発生手段に前記第１および第２の地絡過電流継電装置トリップ信号をそれぞれ発生させる手段（５３₃，５３₄，５３₅）をさらに備え、前記受電端地絡過電流継電装置が、前記第３および第４の遮断器が遮断されていないことを条件に前記第３および第４の地絡過電流継電装置トリップ信号発生手段に前記第３および第４の地絡過電流継電装置トリップ信号をそれぞれ発生させる手段（８３₃，８３₄，８３₅）をさらに備えてもよい。
前記送電端地絡過電流継電装置が、前記平衡２回線送電線の送電端正相電圧（Ｖ_1S）の大きさが整定値以下になったことを示す第１のＵＶＧ出力信号（Ｓ_UVG1）が第１の短絡検出用地絡不足電圧継電装置から入力されていないことを条件に、前記第１および第２の地絡過電流継電装置トリップ信号発生手段に前記第１および第２の地絡過電流継電装置トリップ信号をそれぞれ発生させる手段（５３₄，５３₅）をさらに備え、前記受電端地絡過電流継電装置が、前記平衡２回線送電線の受電端正相電圧（Ｖ_1R）の大きさが整定値以下になったことを示す第２のＵＶＧ出力信号（Ｓ_UVG2）が第２の短絡検出用地絡不足電圧継電装置から入力されていないことを条件に、前記第３および第４の地絡過電流継電装置トリップ信号発生手段に前記第３および第４の地絡過電流継電装置トリップ信号をそれぞれ発生させる手段（８３₄，８３₅）をさらに備えてもよい。 The ground fault protection relay system of the present invention is a ground fault protection relay system for protecting a balanced two-line power transmission line from a ground fault, and is installed in the balanced two-line power transmission line. A ground fault overcurrent relay device (11; 12) that operates based on a difference current between zero-phase currents flowing through the first and second transmission lines (1L, 2L) of the two-line transmission lines, and the first and second And a first ground fault direction relay device (21 ₁ , 21 ₂ ; 22 ₁ , 22 ₂ ) installed on each of the two power transmission lines, in the first ground fault direction relay device When detecting a ground fault occurring in the direction of the first power transmission line and also detecting the ground fault in the ground fault overcurrent relay device, a circuit breaker (4 ₁ , 4, 4 ₃₎ outputs a trip signal for blocking the said second earth fault direction relay electric When detecting a ground fault in the direction of the second power transmission line and detecting the ground fault in the ground fault overcurrent relay device, another circuit breaker installed in the second power transmission line ( 4 ₂ , 4 ₄ ), another trip signal for shutting off is output.
The ground fault protection relay system of the present invention is a ground fault protection relay system for protecting a balanced two-line transmission line from a ground fault, and is installed at a power transmission end of the balanced two-line transmission line. A power transmission terminal ground fault overcurrent relay device (11) and first and second power transmission terminal ground fault direction relay devices (21 ₁ , 21 ₂ ) are provided, and the first power transmission terminal ground fault direction relay device is provided. However, when it is detected that a ground fault has occurred in the first transmission line (1L) direction of the balanced two-line transmission line, the first fault line determination result signal (S ₁ ) is transmitted to the transmission terminal ground fault overcurrent relay. 1st relay judgment means (31) which outputs to an apparatus, and the said 2nd power transmission end ground fault direction relay apparatus is a ground fault accident in the 2nd power transmission line (2L) direction of the said balanced 2 line power transmission line the sending end locations fault over photoelectrically detects the second fault line determination result signal (S ₂₎ that but generated A second relay judging means for outputting to the relay device (41), wherein the sending end locations fault overcurrent relay device, the first of the first zero-phase current flowing through the sending end of the transmission line (I ₀₁₎ And occurrence of a ground fault in the first or second transmission line based on the difference current (I ₀₁ -I ₀₂ ) of the second zero-phase current (I ₀₂ ) flowing through the transmission end of the second transmission line A ground fault detection means (51) for detecting the fault, and the ground fault detection means detects the occurrence of a ground fault and the first fault line determination result from the first power transmission terminal ground fault relay device. When the signal is input, a first ground fault overcurrent relay trip signal (T _OCG1 ) for breaking the first circuit breaker (4 ₁ ) installed at the power transmission end of the first transmission line is _sent . a first ground fault overcurrent relay device trip signal generating means for generating (53 _1), said ground fault detecting means When the occurrence of a ground fault is detected and the second fault line determination result signal is input from the second power transmission end ground fault direction relay device, it is installed at the power transmission end of the second power transmission line. the second circuit breaker has (4 ₂₎ second ground fault overcurrent relay device trip signal (T _OCG2) second ground fault overcurrent relay device trip signal generating means for generating for blocking (53 ₂₎ It is characterized by providing.
Here, a receiving end ground fault overcurrent relay device (12) and first and second receiving end ground fault direction relay devices (22 ₁ , 22 ₂ ) installed at the receiving end of the balanced two-line transmission line, And when the first power receiving end ground fault direction relay device detects that a ground fault has occurred in the first power transmission line direction, a third fault line determination result signal (S ₃ ) is provided. A third relay determining means (61) for outputting to the power receiving end ground fault overcurrent relay device is provided, and the second power receiving end ground fault direction relay device causes a ground fault in the second power transmission line direction. When it is detected that a fault has occurred, a fourth relay judgment means (71) is provided for outputting a fourth fault line judgment result signal (S ₄ ) to the power receiving terminal ground fault overcurrent relay device, and the power receiving terminal ground fault overcurrent relay is provided. The electric device is connected to a third zero-phase ground fault current (I ₀₃ ) flowing through the receiving end of the first transmission line. And a ground fault in the first or second transmission line based on the difference current (I ₀₃ -I ₀₄ ) of the fourth zero-phase ground fault current (I ₀₄ ) flowing through the receiving end of the second transmission line. The other ground fault detection means (81) for detecting the occurrence of the ground fault, and the other ground fault fault detection means detects the occurrence of the ground fault and the first receiving end ground fault direction relay device When the fault line determination result signal 3 is input, the third ground fault overcurrent relay trip for breaking the _third circuit breaker (4 ₃ ) installed at the receiving end of the first transmission line A third ground fault overcurrent relay trip signal generating means (83 ₁ ) for generating a signal (T _OCG3 ), and detecting the occurrence of a ground fault in the ground fault detecting means and the second power receiving terminal When the fourth fault line determination result signal is input from the tangential relay device, the second power transmission line Fourth breaker installed in the receiving end (4 ₄₎ Fourth ground fault overcurrent relay device trip signal (T _OCG4) fourth ground fault overcurrent relay device trip signal generator for generating for blocking Means (83 ₂ ).
The first and second ground fault overcurrent relay trip signal generating means is connected to the first and second ground fault overcurrent relay trip signal generating means on condition that the first and second circuit breakers are not cut off. And a means (53 ₃ , 53 ₄ , 53 ₅ ) for generating a second ground fault overcurrent relay trip signal, respectively, and the power receiving end ground fault overcurrent relay device includes the third and fourth interruptions. Means for causing the third and fourth ground fault overcurrent relay trip signal generating means to generate the third and fourth ground fault overcurrent relay trip signals, respectively, on condition that the device is not cut off (83); ₃ , 83 ₄ , 83 ₅ ).
A first UVG output signal (S _UVG1 ) indicating that the magnitude of the positive phase voltage (V _1S ) of the power transmission end of the balanced two-line transmission line has become equal to or less than a set value is received by the power transmission end ground fault overcurrent relay device. The first and second ground fault overcurrents are supplied to the first and second ground fault overcurrent relay trip signal generating means on condition that the first short circuit detection ground fault undervoltage relay is not input. Means (53 ₄ , 53 ₅ ) for generating relay device trip signals are further provided, and the power receiving end ground fault overcurrent relay device has a magnitude of a receiving end positive phase voltage (V _1R ) of the balanced two-line transmission line. On the condition that the second UVG output signal (S _UVG2 ) indicating that the value is equal to or less than the set value is not input from the second short-circuiting detection ground fault undervoltage relay device. The ground fault overcurrent relay trip signal generating means is And the fourth ground fault overcurrent relay device trip signal means for generating respectively (83 _4, 83 ₅₎ may further comprise a.

本発明の地絡保護継電システムは、以下に示す効果を奏する。
（１）差電流監視型の地絡過電流継電装置と２つの地絡方向継電装置とを組み合わせて、地絡事故検出を地絡過電流継電装置で行い事故回線判定を地絡方向継電装置で行うことにより、従来の地絡保護継電システムにおいて主保護として用いられていた地絡回線選択継電装置を不要にすることができるため、上述した零相循環電流による遮断器の不要遮断を防止することができるので、供給信頼度の低下を招くことがない。
（２）地絡回線選択継電装置は電圧要素と電流要素とに基づいて動作するために零相電圧を印加したり方向試験を行ったりする必要があるが、地絡過電流継電装置は電流要素のみに基づいて動作するために試験を容易に行うことができる。 The ground fault protection relay system of the present invention has the following effects.
(1) By combining a ground fault overcurrent relay device of difference current monitoring type and two ground fault direction relay devices, a ground fault is detected by the ground fault overcurrent relay device, and fault line judgment is performed in the ground fault direction relay. By using the device, the ground fault line selection relay device used as the main protection in the conventional ground fault protection relay system can be made unnecessary. Therefore, the supply reliability is not lowered.
(2) In order to operate the ground fault line selection relay device based on the voltage element and the current element, it is necessary to apply a zero-phase voltage or to conduct a direction test. Tests can be easily performed to operate on elements only.

上記の目的を、平衡２回線送電線の第１の送電線に設置された第１の地絡方向継電装置において第１の送電線方向で発生した地絡事故を検出するとともに地絡過電流継電装置においてもこの地絡事故を検出すると、第１の送電線に設置された遮断器を遮断するためのトリップ信号を出力し、平衡２回線送電線の第２の送電線に設置された第２の地絡方向継電装置において第２の送電線方向で発生した地絡事故を検出するとともに地絡過電流継電装置においてもこの地絡事故を検出すると、第２の送電線に設置された他の遮断器を遮断するための他のトリップ信号を出力することにより実現した。 The above object is achieved by detecting a ground fault in the first power line direction relay device installed in the first power line of the balanced two-line power line and detecting a ground fault overcurrent relay. When this ground fault is detected also in the electric device, a trip signal for breaking the circuit breaker installed in the first transmission line is output, and the second transmission line installed in the balanced two-line transmission line is output. When a ground fault occurred in the direction of the second power transmission line in the ground fault direction relay device 2 and when this ground fault was detected also in the ground fault overcurrent relay device, it was installed in the second power transmission line. This was realized by outputting another trip signal for breaking other circuit breakers.

以下、本発明の地絡保護継電システムの実施例について図面を参照して説明する。
本発明の一実施例による地絡保護継電システムは、従来の地絡保護継電システムでは地絡事故検出および事故回線判定を地絡回線選択継電装置で行っていたが、差電流監視型の地絡過電流継電装置（ＯＣＧ）と２つの地絡方向継電装置（ＤＧ）とを組み合わせることにより地絡事故検出を地絡過電流継電装置で行い事故回線判定を地絡方向継電装置で行うようにしたことを特徴とする。 Hereinafter, embodiments of the ground fault protection relay system of the present invention will be described with reference to the drawings.
In the ground fault protection relay system according to the embodiment of the present invention, in the conventional ground fault protection relay system, the ground fault detection and the fault line determination are performed by the ground fault line selection relay device. By combining the ground fault overcurrent relay device (OCG) and two ground fault direction relay devices (DG), the ground fault detection is performed by the ground fault overcurrent relay device and the fault line judgment is performed. It is characterized in that it was done in

そのため、本実施例による地絡保護継電システムは、図１に示すように、平衡２回線送電線の送電端に設置された送電端地絡過電流継電装置１１並びに第１および第２の送電端地絡方向継電装置２１₁，２１₂と、平衡２回線送電線の受電端に設置された受電端地絡過電流継電装置１２並びに第１および第２の受電端地絡方向継電装置２２₁，２２₂とを具備する。 Therefore, the ground fault protection relay system according to the present embodiment is, as shown in FIG. 1, the power transmission terminal ground fault overcurrent relay device 11 and the first and second power transmissions installed at the power transmission terminal of the balanced two-line power transmission line. Terminal ground fault direction relay devices 21 ₁ and 21 ₂ , power receiving end ground fault overcurrent relay device 12 installed at the power receiving end of the balanced two-line transmission line, and first and second power receiving end ground fault direction relay devices 22 ₁ , 22 ₂ .

第１の送電端地絡方向継電装置２１₁は、図２に示すようにリレー判定回路３１と第１乃至第３の遅延回路（タイマー）３２₁〜３２₃と論理積回路３３と論理和回路３４とを有する第１の送電端地絡方向継電装置トリップ信号発生回路３０を備える。 As shown in FIG. 2, the first power transmission terminal ground fault direction relay device 21 ₁ includes a relay determination circuit 31, first to third delay circuits (timers) 32 _{1 to} 32 ₃ , a logical product circuit 33, and a logical sum. A first power transmission ground fault direction relay device trip signal generation circuit 30 having a circuit 34 is provided.

リレー判定回路３１は、平衡２回線送電線の第１の送電線１Ｌの送電端に設置された第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁と送電端母線に設置された第１の接地形計器用変圧器（ＥＶＴ）５₁から入力される送電端零相電圧Ｖ_0Sとに基づいて事故回線判定を行う（図１参照）。
すなわち、リレー判定回路３１は、第１の零相電流Ｉ₀₁の大きさと送電端零相電圧Ｖ_0Sおよび第１の零相電流Ｉ₀₁の位相関係とに基づいて自回線（第１の送電線１Ｌ）方向に発生した地絡事故を検出すると、ハイレベルの第１の事故回線判定結果信号Ｓ₁を出力する。
第１の事故回線判定結果信号Ｓ₁は論理積回路３３および送電端地絡過電流継電装置１１に出力される。 Relay determining circuit 31, the sending end and the first zero-phase current I ₀₁ which is input from the first zero-phase current transformer 3 ₁ installed on the sending end of the first transmission line 1L of the equilibrium 2-circuit transmission line conducting an accident line determination based on the first earth type potential transformer (EVT) 5 ₁ sending end zero-phase voltage is inputted from the V _0S installed in bus (see FIG. 1).
That is, the relay determining circuit 31, the first zero-phase current I ₀₁ of the size and sending end zero-phase voltage V _0S and the first zero-phase current I ₀₁ of the own channel based on the phase relationship (first transmission line 1L) When a ground fault that has occurred in the direction is detected, a first fault line determination result signal S ₁ at a high level is output.
The first fault line determination result signal S ₁ is output to the AND circuit 33 and the power transmission terminal ground fault overcurrent relay device 11.

第１の遅延回路３２₁は、不図示の第１の地絡検出用地絡過電圧継電装置（ＯＶＧ）から入力される第１のＯＶＧ出力信号Ｓ_OVG1を第１の時限協調時間ＧＴ１₁だけ遅延する。ここで、第１の地絡検出用地絡過電圧継電装置は、送電端零相電圧Ｖ_0Sの大きさが整定値以上になるとハイレベルの第１のＯＶＧ出力信号Ｓ_OVG1を出力する。また、第１の時限協調時間ＧＴ１₁は、第１の送電線１Ｌの受電端背後の送電線に設置された他の地絡方向継電装置（不図示）との時限協調のために設定される（たとえば８００ｍｓに設定される）。
論理積回路３３は、リレー判定回路３１から入力される第１の事故回線判定結果信号Ｓ₁と第１の遅延回路３２₁によって第１の時限協調時間ＧＴ１₁だけ遅延された第１のＯＶＧ出力信号Ｓ_OVG1との論理積をとる。
第２の遅延回路３２₂は、論理積回路３３の出力信号を第１の零相自由振動誤動作防止時間ＧＴ２₁だけ遅延する。ここで、第１の零相自由振動誤動作防止時間ＧＴ２₁は、零相自由振動（事故点切離し後も零相電圧が一定時間だけ残る現象）による誤動作防止のために設定される（通常は１００ｍｓに設定される）。また、第１の送電端地絡方向継電装置２１₁の動作時限は第１の時限協調時間ＧＴ１₁と第１の零相自由振動誤動作防止時間ＧＴ２₁との合計時間（＝ＧＴ１₁＋ＧＴ２₁）となる。 The first delay circuit 32 ₁ delays the first OVG output signal S _OVG1 input from a first ground fault detection ground fault overvoltage relay (OVG) (not shown) by a first time- _dependent coordination time GT _11. To do. Here, the first ground fault overvoltage relay device for ground fault detection outputs a high-level first OVG output signal S _OVG1 when the magnitude of the power transmission end zero-phase voltage V _0S becomes a set value or more. The first timed coordination time GT1 ₁ is set for the timed coordination with the first transmission line 1L other ground direction relay device installed in the receiving end behind the transmission line (not shown) (For example, set to 800 ms).
The AND circuit 33 receives the first fault line determination result signal S ₁ input from the relay determination circuit 31 and the first OVG output delayed by the first time limit coordination time GT1 ₁ by the first delay circuit 32 ₁ . The logical product with the signal S _OVG1 is obtained.
The second delay circuit 32 ₂ delays the output signal of the logical product circuit 33 by the first zero-phase free vibration malfunction prevention time GT2 ₁ . Here, the first zero-phase free vibration lockout time GT2 ₁ is the zero-phase free vibration is set to prevent malfunction due to (after the accident point disconnecting also the zero-phase voltage only remains phenomenon predetermined time) (typically 100ms To be set). The first sending end ground fault direction relay device 21 ₁ of the operation time period is the total time (= GT1 ₁ + GT2 ₁ of ₁ GT2 first timed coordination time GT1 ₁ and the first zero-phase free vibration lockout time )

第３の遅延回路３２₃は、第１のＯＶＧ出力信号Ｓ_OVG1を第１のＯＶＧ遮断時間ＧＴ３₁だけ遅延する。ここで、第１のＯＶＧ遮断時間ＧＴ３₁は、第１の地絡検出用地絡過電圧継電装置の動作だけで、第１の送電線１Ｌの送電端に設置された第１の遮断器４₁（図１参照）を遮断させるために設定される。 The third delay circuit 32 ₃ delays the first OVG output signal S _OVG1 only first OVG breaking time GT3 _1. Here, the first OVG breaking time GT3 ₁ is only the operation of the first ground detection site fault over-voltage relay device, a first breaker 4 ₁ installed on the sending end of the first transmission line 1L (See FIG. 1).

論理和回路３４は、第２の遅延回路３２₂の出力信号と第３の遅延回路３２₃の出力信号との論理和をとる。論理和回路３４からは、第１の遮断器４₁を遮断するための第１の地絡方向継電装置トリップ信号Ｔ_DG1が第１の遮断器４₁に出力される。 The logical sum circuit 34 calculates the logical sum of the output signal of the _second delay circuit 32 _{2 and} the output signal of the third delay circuit 32 ₃ . The OR circuit 34, a first earth fault direction relay device trip signal T _DG1 for blocking the first breaker 4 ₁ is output to the first breaker 4 _1.

第２の送電端地絡方向継電装置２１₂は、図３に示すようにリレー判定回路４１と第１乃至第３の遅延回路（タイマー）４２₁〜４２₃と論理積回路４３と論理和回路４４とを有する第２の送電端地絡方向継電装置トリップ信号発生回路４０を備える。 As shown in FIG. 3, the second power transmission ground fault relay device 21 ₂ includes a relay determination circuit 41, first to third delay circuits (timers) 42 _{1 to} 42 ₃ , a logical product circuit 43, and a logical sum. And a second power transmission terminal ground fault direction relay device trip signal generating circuit 40 having a circuit 44.

リレー判定回路４１は、平衡２回線送電線の第２の送電線２Ｌの送電端に設置された第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂と第１の接地形計器用変圧器５₁から入力される送電端零相電圧Ｖ_0Sとに基づいて事故回線判定を行う（図１参照）。
すなわち、リレー判定回路４１は、第２の零相電流Ｉ₀₂の大きさと送電端零相電圧Ｖ_0Sおよび第２の零相電流Ｉ₀₂の位相関係とに基づいて自回線（第２の送電線２Ｌ）方向に発生した地絡事故を検出すると、ハイレベルの第２の事故回線判定結果信号Ｓ₂を出力する。
第２の事故回線判定結果信号Ｓ₂は論理積回路４３および送電端地絡過電流継電装置１１に出力される。 Relay determining circuit 41, a second zero-phase current I ₀₂ which is input the second from the zero-phase current transformer 3 ₂ installed on the sending end of the second transmission line 2L of the equilibrium 2-circuit transmission line first of conducting an accident line determination based on the sending end zero-phase voltage V _0S inputted from earth type potential transformer 5 ₁ (see FIG. 1).
That is, the relay determining circuit 41, a second zero-phase current I ₀₂ of the size and sending end zero-phase voltage V _0S and second self-line based on the phase relation of the zero-phase current I ₀₂ (second transmission line Upon detecting a ground fault generated in 2L) direction, and outputs a high-level second accident line determination result signal S _2.
The second fault line determination result signal S ₂ is output to the AND circuit 43 and the power transmission terminal ground fault overcurrent relay device 11.

第１の遅延回路３２₁は、第１の地絡検出用地絡過電圧継電装置から入力される第１のＯＶＧ出力信号Ｓ_OVG1を第２の時限協調時間ＧＴ１₂だけ遅延する。ここで、第２の時限協調時間ＧＴ１₂は、第２の送電線２Ｌの受電端背後の送電線に設置された他の地絡方向継電装置（不図示）との時限協調のために設定される（たとえば８００ｍｓに設定される）。
論理積回路４３は、リレー判定回路４１から入力される第２の事故回線判定結果信号Ｓ₂と第１の遅延回路４２₁によって第２の時限協調時間ＧＴ１₂だけ遅延された第１のＯＶＧ出力信号Ｓ_OVG1との論理積をとる。
第２の遅延回路４２₂は、論理積回路４３の出力信号を第２の零相自由振動誤動作防止時間ＧＴ２₂だけ遅延する。したがって、第２の送電端地絡方向継電装置２１₂の動作時限は第２の時限協調時間ＧＴ１₂と第２の零相自由振動誤動作防止時間ＧＴ２₂との合計時間（＝ＧＴ１₂＋ＧＴ２₂）となる。 The first delay circuit 32 ₁ delays the first OVG output signal S _OVG1 inputted from the first ground detection site fault over-voltage relay device only GT1 ₂ second timed coordination time. The second timed coordination time GT1 ₂ is set for timed coordination with the second transmission line 2L other ground direction relay device installed in the receiving end behind the transmission line (not shown) (For example, set to 800 ms).
The AND circuit 43 outputs the first OVG output delayed by the second time limit coordination time GT1 ₂ by the second fault line determination result signal S ₂ input from the relay determination circuit 41 and the first delay circuit 42 ₁ . The logical product with the signal S _OVG1 is obtained.
The second delay circuit 42 ₂ delays the output signal of the AND circuit 43 by the second zero-phase free vibration malfunction prevention time GT _{2 2} . Thus, the second sending end operation timed earth fault direction relay device 21 ₂ Total time (= GT1 ₂ + GT2 ₂ with ₂ second timed coordination time GT1 ₂ and the second zero-phase free vibration lockout time GT2 )

第３の遅延回路４２₃は、第１のＯＶＧ出力信号Ｓ_OVG1を第２のＯＶＧ遮断時間ＧＴ３₂だけ遅延する。ここで、第２のＯＶＧ遮断時間ＧＴ３₂は、第１の地絡検出用地絡過電圧継電装置の動作だけで、第２の送電線２Ｌの送電端に設置された第２の遮断器４₂（図１参照）を遮断させるために設定される。 The third delay circuit 42 ₃ delays the first OVG output signal S _OVG1 by the second OVG cutoff time GT3 ₂ . Here, the second OVG cutoff time GT3 ₂ is the second circuit breaker 4 ₂ installed at the power transmission end of the second power transmission line 2L only by the operation of the first ground fault detection ground fault overvoltage relay device. (See FIG. 1).

論理和回路４４は、第２の遅延回路４２₂の出力信号と第３の遅延回路４２₃の出力信号との論理和をとる。論理和回路４４からは、第２の遮断器４₂を遮断するための第２の地絡方向継電装置トリップ信号Ｔ_DG2が第２の遮断器４₂に出力される。 OR circuit 44 takes the logical sum of the second delay circuit 42 and _second output signal and the third delay circuit 42 ₃ of the output signal. The OR circuit 44, a second ground fault direction relay device trip signal T _DG2 for blocking the second circuit breaker 4 ₂ is output to the second circuit breaker 4 _2.

送電端地絡過電流継電装置１１は、図４に示すように地絡事故検出回路５１と第１および第２の遅延回路５２₁，５２₂と第１乃至第５の論理積回路５３₁〜５３₅とを有する送電端地絡過電流継電装置トリップ信号発生回路５０を備える。 As shown in FIG. 4, the power transmission terminal ground fault overcurrent relay device 11 includes a ground fault detection circuit 51, first and second delay circuits 52 ₁ and 52 _2, and first to fifth AND circuits 53 ₁ to 53 ₁ . comprising a sending end locations fault overcurrent relay device trip signal generating circuit 50 and a 53 _5.

地絡事故検出回路５１は、第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁および第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂の差電流Ｉ₀₁−Ｉ₀₂に基づいて第１または第２の送電線１Ｌ，２Ｌにおける地絡事故の発生を検出する。
すなわち、地絡事故検出回路５１は、差電流Ｉ₀₁−Ｉ₀₂の大きさが整定値以上であると、第１または第２の送電線１Ｌ，２Ｌにおいて地絡事故が発生したと判定して、第１および第２の論理積回路５３₁，５３₂にハイレベルの出力信号を出力する。 A ground fault detection circuit 51, a second zero-phase inputted from the first zero-phase current I ₀₁ and the second zero-phase current transformer 3 ₂ input from the first zero-phase current transformer 3 ₁ The occurrence of a ground fault in the first or second power transmission line 1L, 2L is detected based on the difference current I ₀₁ -I ₀₂ of the current I ₀₂ .
That is, the ground fault detection circuit 51 determines that a ground fault has occurred in the first or second power transmission line 1L, 2L when the magnitude of the difference current I ₀₁ -I ₀₂ is equal to or greater than a set value. A high level output signal is output to the first and second AND circuits 53 ₁ and 53 ₂ .

第１の論理積回路５３₁は、地絡事故検出回路５１の出力信号と第１の送電端地絡方向継電装置２１₁から入力される第１の地絡事故判定信号Ｓ₁と第２の送電端地絡方向継電装置２１₂から入力される第２の地絡事故判定信号Ｓ₂の極性を反転した信号（−Ｓ₂）と第１の地絡検出用地絡過電圧継電装置から入力される第１のＯＶＧ出力信号Ｓ_OVG1との論理積をとる。
第２の論理積回路５３₂は、地絡事故検出回路５１の出力信号と第１の地絡事故判定信号Ｓ₁の極性を反転した信号（−Ｓ₁）と第２の地絡事故判定信号Ｓ₂と第１のＯＶＧ出力信号Ｓ_OVG1との論理積をとる。 The first AND circuit 53 ₁ includes the output signal of the ground fault detection circuit 51, the first ground fault determination signal S ₁ and the second input from the first power transmission ground fault direction relay device 21 ₁ . From the signal (−S ₂ ) obtained by inverting the polarity of the _second ground fault determination signal S ₂ inputted from the power transmission end ground fault direction relay device 21 ₂ and the first ground fault detection ground fault overvoltage relay device. The logical product of the input first OVG output signal S _OVG1 is obtained.
The second AND circuit 53 ₂ includes a signal (−S ₁ ) obtained by inverting the polarities of the output signal of the ground fault detection circuit 51 and the first ground fault determination signal S ₁ and the second ground fault determination signal. The logical product of S ₂ and the first OVG output signal S _OVG1 is obtained.

第３の論理積回路５３₃は、第１の遮断器４₁から入力される第１の接点信号Ｓ_CB1（第１の遮断器４₁が遮断されていない状態ではハイレベルの信号）と第２の遮断器４₂から入力される第２の接点信号Ｓ_CB2（第２の遮断器４₂が遮断されていない状態ではハイレベルの信号）との論理積をとる。 The third AND circuit 53 ₃ includes a first contact signal S _CB1 (a high level signal when the first circuit breaker 4 ₁ is not cut off) input from the first circuit breaker 4 ₁ and the first contact signal S _CB1 . ANDing the second contact signal S _CB2 inputted from the second circuit breaker 4 ₂ (high-level signal in a state in which the second circuit breaker 4 ₂ is not blocked).

第４の論理積回路５３₄は、第１の論理積回路５３₁の出力信号と第３の論理積回路５３₃の出力信号と不図示の第１の短絡検出用地絡不足電圧継電装置（ＵＶＧ）から入力される第１のＵＶＧ出力信号Ｓ_UVG1の極性を反転した信号（−Ｓ_UVG1）との論理積をとる。ここで、第１の短絡検出用地絡不足電圧継電装置は、送電端正相電圧Ｖ_1Sの大きさが整定値以下になるとハイレベルの第１のＵＶＧ出力信号Ｓ_UVG1を出力する。
第１の遅延回路５２₁は、第４の論理積回路５３₄の出力信号を第３の零相自由振動誤動作防止時間ＧＴ２₃だけ遅延する。第１の遅延回路５２₁からは、第１の遮断器４₁を遮断するための第１の地絡過電流継電装置トリップ信号Ｔ_OCG1が第１の遮断器４₁に出力される。したがって、第１の地絡過電流継電装置トリップ信号Ｔ_OCG1については、送電端地絡過電流継電装置１１の動作時限は第３の零相自由振動誤動作防止時間ＧＴ２₂となる。
なお、第１の地絡過電流継電装置トリップ信号Ｔ_OCG1は、第１のＯＶＧ出力信号Ｓ_OVG1がハイレベルでありかつ第１および第２の接点信号Ｓ_CB1，Ｓ_CB2がハイレベルでありかつ第１のＵＶＧ出力信号Ｓ_UVG1がロウレベルであることを条件に、第１の遮断器４₁に出力される。 The fourth AND circuit 53 _4, the first AND circuit 53 ₁ of the output signal and the third AND circuit 53 _third output signal and the first short detection site絡不undervoltage relay device (not shown) ( Logical product with the signal (-S _UVG1 ) obtained by inverting the polarity of the first UVG output signal S _UVG1 input from ( _UVG ). Here, the first short-circuit detection ground fault undervoltage relay device outputs a high-level first UVG output signal S _UVG1 when the magnitude of the power transmission end positive phase voltage V _1S becomes a set value or less.
The first delay circuit 52 ₁ delays the output signal of the _fourth AND circuit 534 by the third zero-phase free vibration malfunction prevention time GT2 ₃ . From the first delay circuit 52 _1, the first ground fault overcurrent relay device trip signal T _OCG1 for blocking the first breaker 4 ₁ is output to the first breaker 4 _1. Thus, for the first ground fault overcurrent relay device trip signal T _OCG1, operation timed the sending end locations fault overcurrent relay device 11 becomes GT2 ₂ third zero-phase free vibration lockout time.
The first ground fault overcurrent relay trip signal T _OCG1 is such that the first OVG output signal S _OVG1 is at a high level and the first and second contact signals S _CB1 and S _CB2 are at a high level; on condition that the first UVG output signal S _UVG1 is at a low level is output to the first breaker 4 _1.

第５の論理積回路５３₅は、第２の論理積回路５３₂の出力信号と第３の論理積回路５３₃の出力信号と第１のＵＶＧ出力信号Ｓ_UVG1の極性を反転した信号（−Ｓ_UVG1）との論理積をとる。
第２の遅延回路５２₂は、第５の論理積回路５３₅の出力信号を第４の零相自由振動誤動作防止時間ＧＴ２₄だけ遅延する。第２の遅延回路５２₂からは、第２の遮断器４₂を遮断するための第２の地絡過電流継電装置トリップ信号Ｔ_OCG2が第２の遮断器４₂に出力される。したがって、第２の地絡過電流継電装置トリップ信号Ｔ_OCG2については、送電端地絡過電流継電装置１１の動作時限は第４の零相自由振動誤動作防止時間ＧＴ２₄となる。
なお、第２の地絡過電流継電装置トリップ信号Ｔ_OCG2は、第１のＯＶＧ出力信号Ｓ_OVG1がハイレベルでありかつ第１および第２の接点信号Ｓ_CB1，Ｓ_CB2がハイレベルでありかつ第１のＵＶＧ出力信号Ｓ_UVG1がロウレベルであることを条件に、第２の遮断器４₂に出力される。 Fifth AND circuit 53 _5, a second AND circuit 53 _{and second} output signal and the third AND circuit 53 _third output signal and the first UVG output signal polarity inverted signal of the S _UVG1 (- AND with S _UVG1 ).
The second delay circuit 52 ₂ delays the output signal of the _fifth AND circuit 535 by the fourth zero-phase free vibration malfunction prevention time GT2 ₄ . From the second delay circuit 52 _2, the second earth fault overcurrent relay device trip signal T _OCG2 for blocking the second circuit breaker 4 ₂ is output to the second circuit breaker 4 _2. Thus, for the second ground fault overcurrent relay device trip signal T _OCG2, operation timed the sending end locations fault overcurrent relay device 11 is the fourth zero-phase free vibration lockout time GT2 _4.
Note that the second ground fault overcurrent relay trip signal T _OCG2 is such that the first OVG output signal S _OVG1 is at a high level and the first and second contact signals S _CB1 and S _CB2 are at a high level; first UVG output signal S _UVG1 on condition that the low level is output to the second circuit breaker 4 _2.

第１の受電端地絡方向継電装置２２₁は、図５に示すようにリレー判定回路６１と第１乃至第３の遅延回路（タイマー）６２₁〜６２₃と論理積回路６３と論理和回路６４とを有する第１の受電端地絡方向継電装置トリップ信号発生回路６０を備える。 As shown in FIG. 5, the _first power receiving terminal ground fault direction relay device 22 ₁ includes a relay determination circuit 61, first to third delay circuits (timers) 62 _{1 to} 62 ₃ , a logical product circuit 63, and a logical sum. A first power receiving end ground fault direction relay device trip signal generating circuit 60 having a circuit 64 is provided.

リレー判定回路６１は、第１の送電線１Ｌの受電端に設置された第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃と受電端母線に設置された第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_0Rとに基づいて事故回線判定を行う（図１参照）。
すなわち、リレー判定回路６１は、第３の零相電流Ｉ₀₃の大きさと受電端零相電圧Ｖ_0Rおよび第３の零相電流Ｉ₀₃の位相関係とに基づいて自回線（第１の送電線１Ｌ）方向に発生した地絡事故を検出すると、ハイレベルの第３の事故回線判定結果信号Ｓ₃を出力する。
第３の事故回線判定結果信号Ｓ₃は論理積回路６３および受電端地絡過電流継電装置１２に出力される。 Relay determining circuit 61, first installed in the third third of the receiving end bus and zero-phase current I ₀₃ inputted from the zero-phase current transformer 3 ₃ installed in the receiving end of the first transmission line 1L conducting an accident line determination based on the second receiving end zero-phase voltage V _0R inputted from earth type potential transformer 5 ₂ (see FIG. 1).
That is, the relay determining circuit 61, a third zero-phase current I ₀₃ of the size and receiving end zero-phase voltage V _0R and third zero-phase current I ₀₃ of the own channel based on the phase relationship (first transmission line Upon detecting a ground fault generated in 1L) direction, and outputs a third accident line determination result signal S ₃ of the high level.
The third fault line determination result signal S ₃ is output to the AND circuit 63 and the power receiving terminal ground fault overcurrent relay device 12.

第１の遅延回路６２₁は、不図示の第２の地絡検出用地絡過電圧継電装置（ＯＶＧ）から入力される第２のＯＶＧ出力信号Ｓ_OVG2を第３の時限協調時間ＧＴ１₃だけ遅延する。ここで、第２の地絡検出用地絡過電圧継電装置は、受電端零相電圧Ｖ_0Rの大きさが整定値以上になるとハイレベルの第２のＯＶＧ出力信号Ｓ_OVG2を出力する。また、図２に示した第１の遅延回路３２₁において設定された第１の時限協調時間ＧＴ１₁（たとえば８００ｍｓ）は、時限協調のために、第３の時限協調時間ＧＴ１₃（たとえば４００ｍｓ）よりも大きくなるように設定される（ＧＴ１₁＞ＧＴ１₃）。
論理積回路６３は、リレー判定回路６１から入力される第３の事故回線判定結果信号Ｓ₃と第１の遅延回路６２₁によって第３の時限協調時間ＧＴ１₃だけ遅延された第２のＯＶＧ出力信号Ｓ_OVG2との論理積をとる。
第２の遅延回路６２₂は、論理積回路６３の出力信号を第５の零相自由振動誤動作防止時間ＧＴ２₅だけ遅延する。したがって、第１の受電端地絡方向継電装置２２₁の動作時限は第３の時限協調時間ＧＴ１₃と第５の零相自由振動誤動作防止時間ＧＴ２₅との合計時間（＝ＧＴ１₃＋ＧＴ２₅）となる。 The first delay circuit 62 ₁ delays the second OVG output signal S _OVG2 input from a second ground fault detection ground fault overvoltage relay device (OVG) (not shown) by a third time coordination time GT1 _3. To do. Here, the second ground fault overvoltage relay device for ground fault detection outputs a second OVG output signal S _OVG2 at a high level when the magnitude of the power receiving end zero-phase voltage V _0R exceeds a set value. Further, the first time cooperation time GT1 ₁ (for example, 800 ms) set in the first delay circuit 32 ₁ shown in FIG. 2 is the third time cooperation time GT1 ₃ (for example, 400 ms) for the time cooperation. (GT1 ₁ > GT1 ₃ ).
The AND circuit 63 outputs the second OVG output delayed by the third time limit coordination time GT1 ₃ by the third fault line determination result signal S ₃ input from the relay determination circuit 61 and the first delay circuit 62 ₁ . The logical product with the signal S _OVG2 is obtained.
The second delay circuit 62 ₂ delays the output signal of the AND circuit 63 by the fifth zero-phase free vibration malfunction prevention time GT2 ₅ . Therefore, the operation time limit of the _first power receiving end ground fault direction relay device 22 ₁ is the total time of the third time cooperation time GT1 ₃ and the fifth zero-phase free vibration malfunction prevention time GT2 ₅ (= GT1 ₃ + GT2 ₅ )

第３の遅延回路６２₃は、第２のＯＶＧ出力信号Ｓ_OVG2を第３のＯＶＧ遮断時間ＧＴ３₃だけ遅延する。ここで、第３のＯＶＧ遮断時間ＧＴ３₃は、第２の地絡検出用地絡過電圧継電装置の動作だけで、第１の送電線１Ｌの受電端に設置された第３の遮断器４₃（図１参照）を遮断させるために設定される。 The third delay circuit 62 ₃ delays the second OVG output signal S _OVG2 by the third OVG cutoff time GT3 ₃ . Here, the third OVG cutoff time GT3 ₃ is the third circuit breaker 4 ₃ installed at the power receiving end of the first power transmission line 1L only by the operation of the second ground fault detection ground fault overvoltage relay device. (See FIG. 1).

論理和回路６４は、第２の遅延回路６２₂の出力信号と第３の遅延回路６２₃の出力信号との論理和をとる。論理和回路６４からは、第３の遮断器４₃を遮断するための第２の地絡方向継電装置トリップ信号Ｔ_DG3が第３の遮断器４₃に出力される。 OR circuit 64 takes the logical sum of the second delay circuit 62 and _second output signal and the third delay circuit 62 ₃ of the output signal. The OR circuit 64, a second ground fault direction relay device trip signal T _DG3 for blocking the third breaker 4 ₃ is output to the third circuit breakers 4 _3.

第２の受電端地絡方向継電装置２２₂は、図６に示すようにリレー判定回路７１と第１乃至第３の遅延回路（タイマー）７２₁〜７２₃と論理積回路７３と論理和回路７４とを有する第２の受電端地絡方向継電装置トリップ信号発生回路７０を備える。 As shown in FIG. 6, the _second power receiving end ground fault relay device 22 ₂ includes a relay determination circuit 71, first to third delay circuits (timers) 72 _{1 to} 72 ₃ , a logical product circuit 73, and a logical sum. A second power receiving terminal ground fault direction relay device trip signal generating circuit 70 having a circuit 74 is provided.

リレー判定回路７１は、第２の送電線２Ｌの受電端に設置された第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄と第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_0Rとに基づいて事故回線判定を行う（図１参照）。
すなわち、リレー判定回路７１は、第４の零相電流Ｉ₀₄の大きさと受電端零相電圧Ｖ_0Rおよび第４の零相電流Ｉ₀₄の位相関係とに基づいて自回線（第２の送電線２Ｌ）方向に発生した地絡事故を検出すると、ハイレベルの第４の事故回線判定結果信号Ｓ₄を出力する。
第４の事故回線判定結果信号Ｓ₄は論理積回路７３および受電端地絡過電流継電装置１２に出力される。 Relay determining circuit 71, the fourth and the fourth zero-phase current I ₀₄ inputted from the zero-phase current transformer 3 ₄ transformers for the second ground measuring meter installed in the receiving end of the second transmission line 2L conducting an accident line determined based on the receiving end zero-phase voltage V _0R inputted from vessel 5 ₂ (see FIG. 1).
That is, the relay determining circuit 71, the fourth zero-phase current I ₀₄ of the size and receiving end zero-phase voltage V _0R and the fourth zero-phase current I ₀₄ of the own channel based on the phase relationship (second transmission line Upon detecting a ground fault generated in 2L) direction, and outputs a fourth accident line determination result signal S ₄ of the high level.
The fourth fault line determination result signal S ₄ is output to the AND circuit 73 and the power receiving terminal ground fault overcurrent relay device 12.

第１の遅延回路７２₂は、第２の地絡検出用地絡過電圧継電装置から入力される第２のＯＶＧ出力信号Ｓ_OVG2を第４の時限協調時間ＧＴ１₄だけ遅延する。ここで、図３に示した第１の遅延回路４２₁において設定された第２の時限協調時間ＧＴ１₂（たとえば８００ｍｓ）は、時限協調のために、第４の時限協調時間ＧＴ１₄（たとえば４００ｍｓ）よりも大きくなるように設定される（ＧＴ１₂＞ＧＴ１₄）。
論理積回路７３は、リレー判定回路７１から入力される第４の事故回線判定結果信号Ｓ₄と第１の遅延回路７２₁によって第４の時限協調時間ＧＴ１₄だけ遅延された第２のＯＶＧ出力信号Ｓ_OVG2との論理積をとる。
第２の遅延回路７２₂は、論理積回路７３の出力信号を第６の零相自由振動誤動作防止時間ＧＴ２₆だけ遅延する。したがって、第２の受電端地絡方向継電装置２２₂の動作時限は第４の時限協調時間ＧＴ１₄と第６の零相自由振動誤動作防止時間ＧＴ２₆との合計時間（＝ＧＴ１₄＋ＧＴ２₆）となる。 The first delay circuit 72 ₂ delays the second OVG output signal S _OVG2 inputted from the second ground detection site fault over-voltage relay device by a fourth timed coordination time GT1 _4. Here, the second time cooperation time GT1 ₂ (for example, 800 ms) set in the first delay circuit 42 ₁ shown in FIG. 3 is the fourth time cooperation time GT1 ₄ (for example, 400 ms) for the time cooperation. ) (GT1 ₂ > GT1 ₄ ).
The AND circuit 73 outputs the second OVG output delayed by the fourth time limit coordination time GT1 ₄ by the fourth fault line determination result signal S ₄ input from the relay determination circuit 71 and the first delay circuit 72 ₁ . The logical product with the signal S _OVG2 is obtained.
The second delay circuit 72 ₂ delays the output signal of the AND circuit 73 by the sixth zero-phase free vibration malfunction prevention time GT2 ₆ . Therefore, the operation time limit of the _second power receiving end ground fault direction relay device 22 ₂ is the total time of the fourth time cooperation time GT1 ₄ and the sixth zero-phase free vibration malfunction prevention time GT2 ₆ (= GT1 ₄ + GT2 ₆ )

第３の遅延回路７２₃は、第２のＯＶＧ出力信号Ｓ_OVG2を第４のＯＶＧ遮断時間ＧＴ３₄だけ遅延する。ここで、第４のＯＶＧ遮断時間ＧＴ３₄は、第２の地絡検出用地絡過電圧継電装置の動作だけで、第２の送電線２Ｌの受電端に設置された第４の遮断器４₄（図１参照）を遮断させるために設定される。 The third delay circuit 72 ₃ delays the second OVG output signal S _OVG2 by the fourth OVG cutoff time GT3 ₄ . Here, the fourth OVG cutoff time GT3 ₄ is the fourth circuit breaker 4 ₄ installed at the power receiving end of the second power transmission line 2L only by the operation of the second ground fault detection ground fault overvoltage relay device. (See FIG. 1).

論理和回路７４は、第２の遅延回路７２₂の出力信号と第３の遅延回路７２₃の出力信号との論理和をとる。論理和回路７４からは、第４の遮断器４₄を遮断するための第４の地絡方向継電装置トリップ信号Ｔ_DG4が第４の遮断器４₄に出力される。 OR circuit 74 takes the logical sum of the second delay circuit 72 and _second output signal and the third delay circuit 72 ₃ of the output signal. From the OR circuit 74, the fourth ground direction relay device trip signal T _DG4 for blocking the fourth breaker 4 ₄ is outputted to the fourth circuit breaker 4 _4.

受電端地絡過電流継電装置１２は、図７に示すように地絡事故検出回路８１と第１および第２の遅延回路８２₁，８２₂と第１乃至第５の論理積回路８３₁〜８３₅とを有する送電端地絡過電流継電装置トリップ信号発生回路８０を備える。 As shown in FIG. 7, the power receiving end ground fault overcurrent relay device 12 includes a ground fault detection circuit 81, first and second delay circuits 82 ₁ and 82 _2, and first to fifth AND circuits 83 ₁ to 83 ₁ . comprising a sending end locations fault overcurrent relay device trip signal generating circuit 80 and a 83 _5.

地絡事故検出回路８１は、第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃および第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄の差電流Ｉ₀₃−Ｉ₀₄に基づいて第１および第２の送電線１Ｌ，２Ｌにおける地絡事故の発生を検出する。
すなわち、地絡事故検出回路８１は、差電流Ｉ₀₃−Ｉ₀₄の大きさが整定値以上であると、第１および第２の論理積回路８３₁，８３₂にハイレベルの出力信号を出力する。 A ground fault detection circuit 81, a fourth zero phase input from the third zero-phase current I ₀₃ and the fourth zero-phase current transformer 3 ₄ inputted from the third zero-phase current transformer 3 ₃ The occurrence of a ground fault in the first and second transmission lines 1L and 2L is detected based on the difference current I ₀₃ -I ₀₄ of the current I ₀₄ .
That is, the ground fault detection circuit 81 outputs a high level output signal to the first and second AND circuits 83 ₁ and 83 ₂ when the magnitude of the difference current I ₀₃ -I ₀₄ is equal to or larger than the set value. To do.

第１の論理積回路８３₁は、地絡事故検出回路８１の出力信号と第１の受電端地絡方向継電装置２２₁から入力される第３の地絡事故判定信号Ｓ₃と第２の受電端地絡方向継電装置２２₂から入力される第４の地絡事故判定信号Ｓ₄の極性を反転した信号（−Ｓ₄）と第２の地絡検出用地絡過電圧継電装置から入力される第２のＯＶＧ出力信号Ｓ_OVG2との論理積をとる。
第２の論理積回路８３₂は、地絡事故検出回路８１の出力信号と第３の地絡事故判定信号Ｓ₃の極性を反転した信号（−Ｓ₃）と第４の地絡事故判定信号Ｓ₄と第２のＯＶＧ出力信号Ｓ_OVG2との論理積をとる。 The first AND circuit 83 ₁ includes the output signal of the ground fault detection circuit 81, the third ground fault determination signal S ₃ input from the _first power receiving terminal ground fault direction relay device 22 _1, and the second From the signal (−S ₄ ) obtained by inverting the polarity of the _fourth ground fault accident determination signal S ₄ input from the power receiving end ground fault direction relay device 22 ₂ and the _second ground fault detection ground fault overvoltage relay device. The logical product of the input second OVG output signal S _OVG2 is obtained.
The second AND circuit 83 ₂ includes a signal (−S ₃ ) obtained by inverting the polarities of the output signal of the ground fault detection circuit 81 and the third ground fault determination signal S ₃ and the fourth ground fault determination signal. The logical product of S ₄ and the second OVG output signal S _OVG2 is obtained.

第３の論理積回路８３₃は、第３の遮断器４₃から入力される第３の接点信号Ｓ_CB3（第３の遮断器４₃が遮断されていない状態ではハイレベルの信号）と第４の遮断器４₄から入力される第４の接点信号Ｓ_CB4（第４の遮断器４₄が遮断されていない状態ではハイレベルの信号）との論理積をとる。 The third AND circuit 83 ₃ has a third contact signal S _CB3 (a high level signal when the third circuit breaker 4 ₃ is not cut off) inputted from the third circuit breaker 4 ₃ and the third contact signal S _CB3 . (a fourth state in which the circuit breaker 4 ₄ is not interrupted in the high-level signal) fourth contact signal S _CB4 inputted from breaker 4 ₄ 4 ANDing the.

第４の論理積回路８３₄は、第１の論理積回路８３₁の出力信号と第３の論理積回路８３₃の出力信号と不図示の第２の短絡検出用地絡不足電圧継電装置（ＵＶＧ）から入力される第２のＵＶＧ出力信号Ｓ_UVG2の極性を反転した信号（−Ｓ_UVG2）との論理積をとる。ここで、第２の短絡検出用地絡不足電圧継電装置は、受電端正相電圧Ｖ_1Rの大きさが整定値以下になるとハイレベルの第２のＵＶＧ出力信号Ｓ_UVG2を出力する。
第１の遅延回路８２₁は、第４の論理積回路８３₄の出力信号を第７の零相自由振動誤動作防止時間ＧＴ２₇だけ遅延する。第１の遅延回路８２₁からは、第３の遮断器４₃を遮断するための第３の地絡過電流継電装置トリップ信号Ｔ_OCG3が第３の遮断器４₃に出力される。したがって、第３の地絡過電流継電装置トリップ信号Ｔ_OCG3については、受電端地絡過電流継電装置１２の動作時限は第７の零相自由振動誤動作防止時間ＧＴ２₇となる。
なお、第３の地絡過電流継電装置トリップ信号Ｔ_OCG3は、第２のＯＶＧ出力信号Ｓ_OVG2がハイレベルでありかつ第３および第４の接点信号Ｓ_CB3，Ｓ_CB4がハイレベルでありかつ第２のＵＶＧ出力信号Ｓ_UVG2がロウレベルであることを条件に、第３の遮断器４₃に出力される。 The fourth AND circuit 83 _4, the first AND circuit 83 ₁ of the output signal and the third AND circuit 83 ₃ and the output signal from the second short detection site絡不undervoltage relay device (not shown) ( Logical product with a signal (-S _UVG2 ) obtained by inverting the polarity of the second UVG output signal S _UVG2 input from ( _UVG ). Here, the second short-circuiting detection ground fault undervoltage relay device outputs a high-level second UVG output signal S _UVG2 when the magnitude of the receiving-end positive phase voltage V _1R becomes equal to or less than a set value.
The first delay circuit 82 ₁ delays the output signal of the _fourth AND circuit 834 by the seventh zero-phase free vibration malfunction prevention time GT2 ₇ . From the first delay circuit 82 _1, the third ground fault overcurrent relay device trip signal T _OCG3 for blocking the third breaker 4 ₃ is output to the third circuit breakers 4 _3. Thus, for the third ground fault overcurrent relay device trip signal T _OCG3, operation timed receiving end locations fault overcurrent relay device 12 becomes zero phase free vibration lockout time GT2 ₇ of the seventh.
The third ground fault overcurrent relay trip signal T _OCG3 is such that the second OVG output signal S _OVG2 is at a high level and the third and fourth contact signals S _CB3 and S _CB4 are at a high level. on condition that the second UVG output signal S _UVG2 is at a low level is output to the third circuit breaker 4 _3.

第５の論理積回路８３₅は、第２の論理積回路８３₂の出力信号と第３の論理積回路８３₃の出力信号と第２のＵＶＧ出力信号Ｓ_UVG2の極性を反転した信号（−Ｓ_UVG2）との論理積をとる。
第２の遅延回路８２₂は、第５の論理積回路８３₅の出力信号を第８の零相自由振動誤動作防止時間ＧＴ２₈だけ遅延する。第２の遅延回路８２₂からは、第４の遮断器４₄を遮断するための第４の地絡過電流継電装置トリップ信号Ｔ_OCG4が第４の遮断器４₄に出力される。したがって、第４の地絡過電流継電装置トリップ信号Ｔ_OCG4については、受電端地絡過電流継電装置１２の動作時限は第８の零相自由振動誤動作防止時間ＧＴ２₈となる。
なお、第４の地絡過電流継電装置トリップ信号Ｔ_OCG4は、第２のＯＶＧ出力信号Ｓ_OVG2がハイレベルでありかつ第３および第４の接点信号Ｓ_CB3，Ｓ_CB4がハイレベルでありかつ第２のＵＶＧ出力信号Ｓ_UVG2がロウレベルであることを条件に、第４の遮断器４₄に出力される。 Fifth AND circuit 83 _5, a second AND circuit 83 _{and second} output signal and the third AND circuit 83 ₃ and the output signal from the second UVG output signal polarity inverted signal of the S _UVG2 (- AND with S _UVG2 ).
The second delay circuit 82 ₂ delays the output signal of the _fifth AND circuit 835 by the eighth zero-phase free vibration malfunction prevention time GT2 ₈ . From the second delay circuit 82 _2, the fourth ground fault overcurrent relay device trip signal T _OCG4 for blocking the fourth breaker 4 ₄ is outputted to the fourth circuit breaker 4 _4. Thus, for the fourth ground fault overcurrent relay device trip signal T _OCG4, operation timed receiving end locations fault overcurrent relay device 12 becomes zero phase free vibration lockout time GT2 ₈ eighth.
The fourth ground fault overcurrent relay trip signal T _OCG4 is such that the second OVG output signal S _OVG2 is at a high level, and the third and fourth contact signals S _CB3 and S _CB4 are at a high level. on condition that the second UVG output signal S _UVG2 is at a low level it is outputted to the fourth circuit breaker 4 _4.

次に、図８（ａ）に示すように第１の送電線１Ｌの受電端至近端において地絡事故が発生した場合の本実施例による地絡保護継電システムの動作について、図８（ｂ），（ｃ）を参照して説明する。
なお、図８および図９では、送電端地絡過電流継電装置１１は「ＯＣＧ_S」と、第１の送電端地絡方向継電装置２１₁は「ＤＧ_S1」と、第２の送電端地絡方向継電装置２１₂は「ＤＧ_S2」と、受電端地絡過電流継電装置１２は「ＯＣＧ_R」と、第１の受電地絡方向継電装置２２₁は「ＤＧ_R1」と、第２の受電端地絡方向継電装置２２₂は「ＤＧ_R2」と表記している。 Next, as shown in FIG. 8 (a), the operation of the ground fault protection relay system according to the present embodiment when a ground fault occurs at the power receiving end closest to the first transmission line 1L will be described with reference to FIG. This will be described with reference to b) and (c).
8 and 9, the power transmission end ground fault overcurrent relay device 11 is “OCG _S ”, the first power transmission end ground fault direction relay device 21 ₁ is “DG _S1 ”, and the second power transmission end. The ground fault direction relay device 21 ₂ is “DG _S2 ”, the power receiving end ground fault overcurrent relay device 12 is “OCG _R ”, the first power receiving ground fault direction relay device 22 ₁ is “DG _R1 ”, The second power receiving end ground fault direction relay device 22 ₂ is described as “DG _R2 ”.

第１の送電線１Ｌの受電端至近端において地絡事故が発生すると、第１の受電端地絡方向継電装置２２₁の第１の受電端地絡方向継電装置トリップ信号発生回路６０のリレー判定回路６１（図５参照）は、第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃および第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_ORに基づいて事故回線判定を行い、第１の送電線１Ｌ方向において地絡事故が発生したと判定して、ハイレベルの第３の事故回線判定結果信号Ｓ₃を受電端地絡過電流継電装置１２に出力する。
一方、第２の受電端地絡方向継電装置２２₂の第２の受電端地絡方向継電装置トリップ信号発生回路７０のリレー判定回路７１（図６参照）は、第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄および第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_ORに基づいて事故回線判定を行い、第２の送電線２Ｌ方向において地絡事故が発生していないと判定して、ロウレベルの第４の事故回線判定結果信号Ｓ₄を受電端地絡過電流継電装置１２に出力したままとなる。
また、受電端地絡過電流継電装置１２の受電端地絡過電流継電装置トリップ信号発生回路８０の地絡事故検出回路８１（図７参照）は、第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃および第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄の差電流Ｉ₀₃−Ｉ₀₄に基づいて地絡事故が発生したことを検出して、ハイレベルの出力信号を第１および第２の論理積回路８３₁，８３₂に出力する。
その結果、第２のＯＶＧ出力信号Ｓ_OVG2がハイレベルであるとともに第３および第４の接点信号Ｓ_CB3，Ｓ_CB4がハイレベルであると、第３の過電流継電装置トリップ信号Ｔ_OCG3が第３の遮断器４₃に第７の零相自由振動誤動作防止時間ＧＴ２₇経過後に出力される。
これにより、第３の遮断器４₃は、受電端地絡過電流継電装置１２におけるリレー判定時間、第７の零相自由振動誤動作防止時間ＧＴ２₇および遮断器遮断時間の合計時間経過後に完全に遮断される（図８（ｂ）参照）。 When a ground fault occurs at the power receiving end closest to the first power transmission line 1L, the first power receiving end ground fault direction relay device trip signal generating circuit 60 of the first power receiving end ground fault direction relay device 22 ₁ is used. relay determining circuit 61 (see FIG. 5) is inputted from the third zero-phase current transformer 3 ₃ third zero-phase current I ₀₃ and the second earth type instrument transformer 5 ₂ inputted from perform accident line determined based on the receiving end the zero-phase voltage V _OR, it is determined that the ground fault occurs in the first transmission line 1L direction, receiving a third accident line determination result signal S ₃ of the high-level Output to the terminal ground fault overcurrent relay device 12.
On the other hand, the relay judgment circuit 71 (see FIG. 6) of the second power receiving end ground fault direction relay device trip signal generating circuit 70 of the second power receiving end ground fault direction relay device 22 ₂ has a fourth zero phase change. Nagareki 3 ₄ based on the fourth zero-phase current I ₀₄ and the second receiving end zero-phase voltage V _oR inputted from earth type potential transformer 5 ₂ inputted from perform accident line determination, the second the transmission line is determined as in the 2L direction ground fault does not occur, and remains to output the fourth accident line determination result signal S ₄ of the low level to the receiving end locations fault overcurrent relay device 12.
Further, ground fault detection circuit 81 of the receiving end locations fault overcurrent relay device trip signal generating circuit 80 of the receiving end locations fault overcurrent relay device 12 (see FIG. 7), from the third zero-phase current transformer 3 ₃ ground fault occurs on the basis of a difference current I ₀₃ -I ₀₄ of the fourth zero-phase current I ₀₄ inputted from the third zero-phase current I ₀₃ and the fourth zero-phase current transformer 3 ₄ input When this is detected, a high level output signal is output to the first and second AND circuits 83 ₁ and 83 ₂ .
As a result, when the second OVG output signal S _OVG2 is at high level and the third and fourth contact signals S _CB3 and S _CB4 are at high level, the third overcurrent relay trip signal T _OCG3 is is output to the third circuit breakers 4 ₃ seventh zero-phase free vibration lockout time GT2 ₇ after a.
Accordingly, the third breaker 4 ₃ of the relay determination time at the receiving end locations fault overcurrent relay device 12, completely after a total time of 7 zero-phase free vibration lockout time GT2 ₇ and breaker breaking time of It is blocked (see FIG. 8B).

なお、第１の送電線１Ｌの受電端至近端において地絡事故が発生すると、第１の送電端地絡方向継電装置２１₁の第１の送電端地絡方向継電装置トリップ信号発生回路３０のリレー判定回路３１（図２参照）は、ハイレベルの第１の事故回線判定結果信号Ｓ₁を送電端過電流継電装置１１に出力するが、第２の送電端地絡方向継電装置２１₂の第２の送電端地絡方向継電装置トリップ信号発生回路４０のリレー判定回路４１（図３参照）も、ハイレベルの第２の事故回線判定結果信号Ｓ₂を送電端過電流継電装置１１に出力する。
しかし、このときに第１の送電線１Ｌの送電端に流れる第１の零相電流Ｉ₀₁および第２の送電線２Ｌの送電端に流れる第２の零相電流Ｉ₀₂の差電流Ｉ₀₁−Ｉ₀₂は整定値よりも小さいため、送電端過電流継電装置１１の送電端過電流継電装置トリップ信号発生回路５０の地絡事故検出回路５１（図４参照）は、ロウレベルの出力信号を第１および第２の論理積回路５３₁，５３₂に出力したままとなる。
その結果、第１および第２の地絡過電流継電装置トリップ信号Ｔ_OCG1，Ｔ_OC2は送電端過電流継電装置トリップ信号発生回路５０から出力されないので、第１および第２の遮断器４₁，４₂が遮断されることはない。 When a ground fault occurs at the power receiving end close to the first power transmission line 1L, a first power transmission end ground fault direction relay device trip signal is generated by the first power transmission end ground fault direction relay device 21 ₁ . relay determining circuit 31 of the circuit 30 (see FIG. 2), the first accident line determination result of the high level is output to signals S ₁ to the power transmission end over-current relay device 11, the second sending end earth fault direction relay The relay determination circuit 41 (see FIG. 3) of the second power transmission end ground fault direction relay device trip signal generation circuit 40 of the power transmission device 21 _{2 also} transmits the second fault line determination result signal S ₂ having a high level to the power transmission end. Output to the current relay device 11.
However, at this time, the difference current I ₀₁ − between the first zero-phase current I ₀₁ flowing through the power transmission end of the first power transmission line 1L and the second zero-phase current I ₀₂ flowing through the power transmission end of the second power transmission line 2L Since I ₀₂ is smaller than the set value, the ground fault detection circuit 51 (see FIG. 4) of the power transmission end overcurrent relay trip signal generation circuit 50 of the power transmission end overcurrent relay device 11 outputs a low level output signal. It remains output to the first and second AND circuits 53 ₁ and 53 ₂ .
As a result, the first and second ground fault overcurrent relay device trip signal T _OCG1, T _OC2 is because it is not output from the sending end overcurrent relay device trip signal generating circuit 50, first and second circuit breakers 4 ₁ , 4 ₂ is not blocked.

上述したようにして第３の遮断器４₃が完全に遮断されると第１の送電線１Ｌの送電端を流れる第１の零相電流Ｉ₀₁と第２の送電線２Ｌの送電端を流れる第２の零相電流Ｉ₀₂との差電流Ｉ₀₁−Ｉ₀₂は大きくなるため、第１の送電端地絡方向継電装置２１₁の第１の送電端地絡方向継電装置トリップ信号発生回路３０のリレー判定回路３１（図２参照）は、第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁および第１の接地形計器用変圧器５₁から入力される送電端零相電圧Ｖ_OSに基づいて事故回線判定を行い、第１の送電線１Ｌ方向において地絡事故が発生したと判定して、ハイレベルの第１の事故回線判定結果信号Ｓ₁を送電端地絡過電流継電装置１１に出力している。
一方、第２の送電端地絡方向継電装置２１₂の第２の送電端地絡方向継電装置トリップ信号発生回路４０のリレー判定回路４１（図３参照）は、第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂および第１の接地形計器用変圧器５₁から入力される送電端零相電圧Ｖ_OSに基づいて事故回線判定を行い、第２の送電線２Ｌ方向において地絡事故が発生していないと判定して、ロウレベルの第２の事故回線判定結果信号Ｓ₂を送電端地絡過電流継電装置１１に出力する。
また、送電端地絡過電流継電装置１１の送電端地絡過電流継電装置トリップ信号発生回路５０の地絡事故検出回路５１（図４参照）は、第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁および第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂の差電流Ｉ₀₁−Ｉ₀₂に基づいて地絡事故が発生したことを検出して、ハイレベルの出力信号を第１および第２の論理積回路５３₁，５３₂に出力する。
その結果、第１のＯＶＧ出力信号Ｓ_OVG1がハイレベルであるとともに第１および第２の接点信号Ｓ_CB1，Ｓ_CB2がハイレベルであると、第１の過電流継電装置トリップ信号Ｔ_OCG1が第１の遮断器４₁に第３の零相自由振動誤動作防止時間ＧＴ２₃経過後に出力される。
これにより、第１の遮断器４₁は、第３の遮断器４₃が完全に遮断されたのち、送電端地絡過電流継電装置１１におけるリレー判定時間、第３の零相自由振動誤動作防止時間ＧＴ２₃および遮断器遮断時間の合計時間経過後に完全に遮断される（図８（ｃ）参照）。 Flowing through the third circuit breaker 4 when ₃ is completely shut off from the first zero-phase current I ₀₁ flowing in the sending end of the first transmission line 1L sending end of the second transmission line 2L in the manner described above Since the difference current I ₀₁ -I ₀₂ from the second zero-phase current I ₀₂ becomes large, the first power transmission end ground fault direction relay device 21 ₁ generates the first power transmission end ground fault direction relay device trip signal. relay determining circuit 31 of the circuit 30 (see FIG. 2), the first zero-phase current I ₀₁ and the first earth type input from the instrumentation transformer 5 ₁ input from the first zero-phase current transformer 3 ₁ The fault line determination is performed based on the transmitted power zero-phase voltage V _OS , it is determined that a ground fault has occurred in the direction of the first power transmission line 1L, and the high-level first fault line determination result signal S ₁ Is output to the power transmission terminal ground fault overcurrent relay device 11.
On the other hand, the relay determination circuit 41 (see FIG. 3) of the second power transmission end ground fault direction relay device trip signal generation circuit 40 of the second power transmission end ground fault direction relay device 21 ₂ is used for the second zero phase change. perform accident line determination based on the second zero-phase current I ₀₂ and the first sending end zero-phase voltage V _OS input from the earth type potential transformer 5 ₁ inputted from Nagareki 3 _2, second of it is determined that a ground fault in the transmission line 2L direction has not occurred, and outputs a second accident line determination result signal S ₂ to the sending end locations fault overcurrent relay device 11 at a low level.
In addition, the ground fault detection circuit 51 (see FIG. 4) of the power transmission ground fault overcurrent relay device trip signal generation circuit 50 of the power transmission ground fault overcurrent relay device 11 includes the first zero-phase current transformer 3 _1. ground fault occurs on the basis of a difference current I ₀₁ -I ₀₂ of the first zero-phase current I ₀₁ and the second zero-phase current transformer 3 is inputted from the ₂ second zero-phase current I ₀₂ inputted In response to this, a high level output signal is output to the first and second AND circuits 53 ₁ and 53 ₂ .
As a result, when the first OVG output signal S _OVG1 is high level and the first and second contact signals S _CB1 and S _CB2 are high level, the first overcurrent relay trip signal T _OCG1 is output a third zero-phase free vibration lockout time after GT2 ₃ lapse of the first breaker 4 _1.
Accordingly, the first breaker 4 _1, after the third breaker 4 ₃ is completely cut off, the relay determination time in the sending end locations fault overcurrent relay device 11, preventing the third zero-phase free oscillation malfunction After the total time of the time GT2 ₃ and the circuit breaker breaking time has elapsed, the circuit is completely cut off (see FIG. 8C).

次に、図９（ａ）に示すように第１の送電線１Ｌの送電端至近端において地絡事故が発生した場合の本実施例による地絡保護継電システムの動作について、図９（ｂ），（ｃ）を参照して説明する。 Next, as shown in FIG. 9 (a), the operation of the ground fault protection relay system according to the present embodiment when a ground fault occurs at the power transmission end closest to the first transmission line 1L will be described with reference to FIG. This will be described with reference to b) and (c).

第１の送電線１Ｌの送電端至近端において地絡事故が発生すると、第１の送電端地絡方向継電装置２１₁の第１の送電端地絡方向継電装置トリップ信号発生回路３０のリレー判定回路３１（図２参照）は、第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁および第１の接地形計器用変圧器５₁から入力される送電端零相電圧Ｖ_OSに基づいて事故回線判定を行い、第１の送電線１Ｌ方向において地絡事故が発生したと判定して、ハイレベルの第１の事故回線判定結果信号Ｓ₁を送電端地絡過電流継電装置１１に出力する。
一方、第２の送電端地絡方向継電装置２１₂の第２の送電端地絡方向継電装置トリップ信号発生回路４０のリレー判定回路４１（図３参照）は、第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂および第１の接地形計器用変圧器５₁から入力される送電端零相電圧Ｖ_OSに基づいて事故回線判定を行うが、地絡電流が小さいために第２の送電端地絡方向継電装置２１₂は不動作となるため、第２の送電線２Ｌ方向において地絡事故が発生していないと判定して、ロウレベルの第２の事故回線判定結果信号Ｓ₂を送電端地絡過電流継電装置１１に出力したままとなる。
また、送電端地絡過電流継電装置１１の送電端地絡過電流継電装置トリップ信号発生回路５０の地絡事故検出回路５１（図４参照）は、第１の零相変流器３₁から入力される第１の零相電流Ｉ₀₁および第２の零相変流器３₂から入力される第２の零相電流Ｉ₀₂の差電流Ｉ₀₁−Ｉ₀₂に基づいて地絡事故が発生したことを検出して、ハイレベルの出力信号を第１および第２の論理積回路５３₁，５３₂に出力する。
その結果、第１のＯＶＧ出力信号Ｓ_OVG1がハイレベルであるとともに第１および第２の接点信号Ｓ_CB1，Ｓ_CB2がハイレベルであると、第１の過電流継電装置トリップ信号Ｔ_OCG1が第１の遮断器４₁に第３の零相自由振動誤動作防止時間ＧＴ２₃経過後に出力される。
これにより、第１の遮断器４₁は、送電端地絡過電流継電装置１１におけるリレー判定時間、第３の零相自由振動誤動作防止時間ＧＴ２₃および遮断器遮断時間の合計時間経過後に完全に遮断される（図９（ｂ）参照）。 When a ground fault occurs at the power transmission end close to the first power transmission line 1L, the first power transmission end ground fault direction relay device trip signal generation circuit 30 of the first power transmission end ground fault direction relay device 21 ₁ is used. relay determining circuit 31 (see FIG. 2) is input from the first zero-phase current I ₀₁ and the first earth type instrument transformer 5 ₁ input from the first zero-phase current transformer 3 ₁ The fault line is determined based on the zero-phase voltage V _OS at the transmission end, it is determined that a ground fault has occurred in the direction of the first transmission line 1L, and the first fault line determination result signal S ₁ of high level is transmitted. Output to the ground fault overcurrent relay device 11.
On the other hand, the relay determination circuit 41 (see FIG. 3) of the second power transmission end ground fault direction relay device trip signal generation circuit 40 of the second power transmission end ground fault direction relay device 21 ₂ is used for the second zero phase change. Nagareki 3 ₂ based on the second zero-phase current I ₀₂ and the first sending end zero-phase voltage V _OS input from the earth type potential transformer 5 ₁ input from performing an accident line determination, but the earth Since the fault current is small, the second power transmission terminal ground fault direction relay device 21 ₂ becomes inoperative, so it is determined that no ground fault has occurred in the second power transmission line 2L direction, and the low level first No. ₂ fault line determination result signal S ₂ is still output to the power transmission terminal ground fault overcurrent relay device 11.
In addition, the ground fault detection circuit 51 (see FIG. 4) of the power transmission ground fault overcurrent relay device trip signal generation circuit 50 of the power transmission ground fault overcurrent relay device 11 includes the first zero-phase current transformer 3 _1. ground fault occurs on the basis of a difference current I ₀₁ -I ₀₂ of the first zero-phase current I ₀₁ and the second zero-phase current transformer 3 is inputted from the ₂ second zero-phase current I ₀₂ inputted In response to this, a high level output signal is output to the first and second AND circuits 53 ₁ and 53 ₂ .
As a result, when the first OVG output signal S _OVG1 is high level and the first and second contact signals S _CB1 and S _CB2 are high level, the first overcurrent relay trip signal T _OCG1 is output a third zero-phase free vibration lockout time after GT2 ₃ lapse of the first breaker 4 _1.
Accordingly, the first breaker 4 _1, relay determination time in the sending end locations fault overcurrent relay device 11, completely after a total elapsed time of the third zero-phase free vibration lockout time GT2 ₃ and breaker breaking time It is blocked (see FIG. 9B).

なお、第１の送電線１Ｌの送電端至近端において地絡事故が発生すると、第２の受電端地絡方向継電装置２２₂の第２の受電端地絡方向継電装置トリップ信号発生回路７０のリレー判定回路７１（図６参照）は、ロウレベルの第４の事故回線判定結果信号Ｓ₄を受電端過電流継電装置１２に出力したままであるが、第１の受電端地絡方向継電装置２２₁の第１の受電端地絡方向継電装置トリップ信号発生回路６０のリレー判定回路６１（図５参照）は、ロウレベルの第３の事故回線判定結果信号Ｓ₃を受電端過電流継電装置１２に出力する。
また、このときに第１の送電線１Ｌの受電端に流れる第１の零相電流Ｉ₀₁および第２の送電線２Ｌの受電端に流れる第２の零相電流Ｉ₀₂の差電流Ｉ₀₁−Ｉ₀₂は整定値よりも小さいため、受電端過電流継電装置１２の受電端過電流継電装置トリップ信号発生回路８０の地絡事故検出回路８１（図７参照）は、ロウレベルの出力信号を第１および第２の論理積回路８３₁，８３₂に出力したままとなる。
その結果、第３の地絡過電流継電装置トリップ信号Ｔ_OCG3は受電端過電流継電装置トリップ信号発生回路８０から第３の遮断器４₃に出力されないので、第３の遮断器４₃が遮断されることはない。 In addition, when a ground fault occurs at the power transmission end closest to the first power transmission line 1L, a second power receiving end ground fault direction relay device trip signal is generated by the second power receiving end ground fault direction relay device 22 ₂ . relay determining circuit 71 of the circuit 70 (see FIG. 6), which remains outputs a fourth accident line determination result signal S ₄ of the low level to the receiving end over-current relay device 12, first receiving end earth fault The relay determination circuit 61 (see FIG. 5) of the first power receiving end ground fault direction relay device trip signal generation circuit 60 of the direction relay device 22 ₁ receives the low-level third fault line determination result signal S ₃ as the power receiving end. Output to the overcurrent relay device 12.
At this time, the difference current I ₀₁ − between the first zero-phase current I ₀₁ flowing through the power receiving end of the first power transmission line 1L and the second zero-phase current I ₀₂ flowing through the power receiving end of the second power transmission line 2L Since I ₀₂ is smaller than the set value, the ground fault detection circuit 81 (see FIG. 7) of the receiving end overcurrent relay device trip signal generating circuit 80 of the receiving end overcurrent relay device 12 outputs a low level output signal. It remains output to the first and second AND circuits 83 ₁ and 83 ₂ .
As a result, the third ground fault overcurrent relay trip signal T _OCG3 is not output from the power receiving end overcurrent relay trip signal generation circuit 80 to the third circuit breaker 4 ₃ , so that the third circuit breaker 4 ₃ It will not be blocked.

上述したようにして第１の遮断器４₁が完全に遮断されると第１の送電線１Ｌの受電端を流れる第３の零相電流Ｉ₀₃と第２の送電線２Ｌの受電端を流れる第４の零相電流Ｉ₀₄との差電流Ｉ₀₁−Ｉ₀₂は迂回電流により大きくなるため、第１の受電端地絡方向継電装置２２₁の第１の受電端地絡方向継電装置トリップ信号発生回路６０のリレー判定回路６１（図５参照）は、第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃および第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_ORに基づいて事故回線判定を行い、第１の送電線１Ｌ方向において地絡事故が発生したと判定して、ハイレベルの第３の事故回線判定結果信号Ｓ₃を受電端地絡過電流継電装置１２に出力する。
一方、第２の受電端地絡方向継電装置２２₂の第２の受電端地絡方向継電装置トリップ信号発生回路７０のリレー判定回路７１（図６参照）は、第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄および第２の接地形計器用変圧器５₂から入力される受電端零相電圧Ｖ_ORに基づいて事故回線判定を行い、第２の送電線２Ｌ方向において地絡事故が発生していないと判定して、ロウレベルの第４の事故回線判定結果信号Ｓ₄を受電端地絡過電流継電装置１２に出力したままとなる。
また、受電端地絡過電流継電装置１２の受電端地絡過電流継電装置トリップ信号発生回路８０の地絡事故検出回路８１（図７参照）は、第３の零相変流器３₃から入力される第３の零相電流Ｉ₀₃および第４の零相変流器３₄から入力される第４の零相電流Ｉ₀₄の差電流Ｉ₀₃−Ｉ₀₄に基づいて地絡事故が発生したことを検出して、ハイレベルの出力信号を第１および第２の論理積回路８３₁，８３₂に出力する。
その結果、第２のＯＶＧ出力信号Ｓ_OVG2がハイレベルであるとともに第３および第４の接点信号Ｓ_CB3，Ｓ_CB4がハイレベルであると、第３の過電流継電装置トリップ信号Ｔ_OCG3が第３の遮断器４₃に第７の零相自由振動誤動作防止時間ＧＴ２₇経過後に出力される。
これにより、第３の遮断器４₃は、第１の遮断器４₁が完全に遮断されたのち、受電端地絡過電流継電装置１２におけるリレー判定時間、第７の零相自由振動誤動作防止時間ＧＴ２₇および遮断器遮断時間の合計時間経過後に完全に遮断される（図９（ｃ）参照）。 Flowing the first breaker 4 ₁ is completely shut off in the manner described above with a third zero-phase current I ₀₃ flowing in the receiving end of the first transmission line 1L to the receiving end of the second transmission line 2L fourth to the difference current I ₀₁ -I ₀₂ of the zero-phase current I ₀₄ increases by bypassing the current, the first receiving end earth fault direction relay device 22 ₁ of the first receiving end earth fault direction relay device trip (see FIG. 5) relay determining circuit 61 of the signal generating circuit 60, a third zero-phase current I ₀₃ and the second earth type instrument transformer input from the third zero-phase current transformer 3 ₃ 5 _The fault line determination is performed based on the receiving-end zero-phase voltage V _OR input from _2, and it is determined that a ground fault has occurred in the direction of the first transmission line 1L, and the third fault line determination result of the high level The signal S ₃ is output to the receiving end ground fault overcurrent relay device 12.
On the other hand, the relay judgment circuit 71 (see FIG. 6) of the second power receiving end ground fault direction relay device trip signal generating circuit 70 of the second power receiving end ground fault direction relay device 22 ₂ has a fourth zero phase change. Nagareki 3 ₄ based on the fourth zero-phase current I ₀₄ and the second receiving end zero-phase voltage V _oR inputted from earth type potential transformer 5 ₂ inputted from perform accident line determination, the second the transmission line is determined as in the 2L direction ground fault does not occur, and remains to output the fourth accident line determination result signal S ₄ of the low level to the receiving end locations fault overcurrent relay device 12.
Further, ground fault detection circuit 81 of the receiving end locations fault overcurrent relay device trip signal generating circuit 80 of the receiving end locations fault overcurrent relay device 12 (see FIG. 7), from the third zero-phase current transformer 3 ₃ ground fault occurs on the basis of a difference current I ₀₃ -I ₀₄ of the fourth zero-phase current I ₀₄ inputted from the third zero-phase current I ₀₃ and the fourth zero-phase current transformer 3 ₄ input When this is detected, a high level output signal is output to the first and second AND circuits 83 ₁ and 83 ₂ .
As a result, when the second OVG output signal S _OVG2 is at high level and the third and fourth contact signals S _CB3 and S _CB4 are at high level, the third overcurrent relay trip signal T _OCG3 is is output to the third circuit breakers 4 ₃ seventh zero-phase free vibration lockout time GT2 ₇ after a.
Thereby, after the 1st circuit breaker 4 ₁ is completely interrupted, the third circuit breaker 4 ₃ prevents the relay determination time in the power receiving terminal ground fault overcurrent relay device 12 and the seventh zero-phase free vibration malfunction prevention. After the total time of the time GT2 ₇ and the circuit breaker breaking time has elapsed, it is completely cut off (see FIG. 9 (c)).

以上説明したように、本実施例による地絡保護継電システムを用いても、図１０に示した従来の地絡保護継電システムと同じように平衡２回線送電線を地絡事故から保護することができる。 As described above, even when the ground fault protection relay system according to the present embodiment is used, the balanced two-line transmission line is protected from the ground fault as in the conventional ground fault protection relay system shown in FIG. be able to.

また、零相循環電流が流れても、送電端地絡過電流継電装置１１および受電端地絡過電流継電装置１２は地絡事故を検出するが、第１および第２の送電端地絡方向継電装置２１₁，２１₂と第１および第２の受電端地絡方向継電装置２２₁，２２₂とは動作しない（自回線事故とは判定しない）ため、第１乃至第４の遮断器４₁〜４₄が遮断されることはない。 Even if the zero-phase circulating current flows, the power transmission terminal ground fault overcurrent relay device 11 and the power receiving terminal ground fault overcurrent relay device 12 detect a ground fault, but the first and second power transmission terminal ground fault directions. Since the relay devices 21 ₁ and 21 ₂ and the first and second power receiving end ground fault direction relay devices 22 ₁ and 22 ₂ do not operate (it is not determined that the own line fault occurs), the first to fourth interruptions The containers 4 ₁ to 4 ₄ are not shut off.

さらに、たとえば第１の送電線１Ｌの受電端背後の送電線において地絡事故（外部地絡事故）が発生すると、第１および第２の送電端地絡方向継電装置２１₁，２１₂は動作する（自回線事故と判定する）が、第１の零相電流Ｉ₀₁と第２の零相電流Ｉ₀₂との差電流Ｉ₀₁−Ｉ₀₂は生じないため、第１および第２の遮断器４₁，４₂が遮断されることはない。
さらにまた、前方に地絡事故が発生して事故回線の判定が不能になったときにたとえば第２の送電線２Ｌの受電端側で地絡事故が発生しても、第１および第２の受電端地絡方向継電装置２２₁，２２₂と受電端地絡過電流継電装置１２とによって第４の遮断器４₄が先行遮断されることにより第１の送電端地絡方向継電装置２１₁が復帰するため、健全回線側の第１の遮断器４が遮断されることはない。 Further, for example, when a ground fault (external ground fault) occurs in the power transmission line behind the power receiving end of the first power transmission line 1L, the first and second power transmission end ground fault direction relay devices 21 ₁ and 21 ₂ are Although operated (determined as an own line fault), a difference current I ₀₁ -I ₀₂ between the first zero-phase current I ₀₁ and the second zero-phase current I ₀₂ does not occur, so the first and second interruptions Units 4 ₁ and 4 ₂ are not shut off.
Furthermore, even if a ground fault occurs on the power receiving end side of the second power transmission line 2L, for example, when the ground fault occurs ahead and determination of the fault line becomes impossible, the first and second The 4th circuit breaker 4 ₄ is cut off in advance by the power receiving end ground fault direction relay devices 22 ₁ and 22 ₂ and the power receiving end ground fault overcurrent relay device 12, whereby the first power transmitting end ground fault direction relay device. Since 21 ₁ is restored, the first circuit breaker 4 on the sound line side is not interrupted.

以上の説明では、第１および第２の送電端地絡方向継電装置２１₁，２１₂と送電端地絡過電流継電装置１１とを個々に構成したが、一体に構成してもよい。第１および第２の受電端地絡方向継電装置２２₁，２２₂と受電端地絡過電流継電装置１２についても同様である。 In the above description, the first and second power transmission terminal ground fault direction relay devices 21 ₁ and 21 ₂ and the power transmission terminal ground fault overcurrent relay device 11 are individually configured, but may be configured integrally. The same applies to the first and second power receiving terminal ground fault direction relay devices 22 ₁ and 22 ₂ and the power receiving terminal ground fault overcurrent relay device 12.

また、平衡２回線送電線の送電端および受電端に地絡過電流継電装置を１つずつ設置したが、地絡過電流継電装置は地絡回線選択継電装置に比べて安価であるため、バックアップ用に他の地絡過電流継電装置を設置してもよい。これにより、いずれか一方の地絡過電流継電装置が故障した場合にも平衡受電を維持させることができる。 Moreover, although one earth fault overcurrent relay device was installed at the power transmission end and the power receiving end of the balanced two-line transmission line, the ground fault over current relay device is cheaper than the ground fault line selection relay device, Another ground fault overcurrent relay device may be installed for backup. Thereby, even when any one of the ground fault overcurrent relay devices fails, the balanced power reception can be maintained.

本発明の一実施例による地絡保護継電システムの構成を示す図である。It is a figure which shows the structure of the ground fault protection relay system by one Example of this invention. 図１に示した第１の送電端地絡方向継電装置２１₁が備える第１の送電端地絡方向継電装置トリップ信号発生回路３０の構成を示すブロック図である。Is a block diagram showing the configuration of the first sending end ground fault direction relay device trip signal generating circuit 30 in which the first sending end ground fault direction relay device 21 ₁ shown in FIG. 1 is provided. 図１に示した第２の送電端地絡方向継電装置２１₂が備える第２の送電端地絡方向継電装置トリップ信号発生回路４０の構成を示すブロック図である。It is a block diagram which shows the structure of the 2nd power transmission terminal ground fault direction relay apparatus trip signal generation circuit 40 with which the 2nd power transmission terminal ground fault direction relay apparatus 21 ₂ shown in FIG. 図１に示した送電端地絡過電流継電装置１１が備える送電端地絡過電流継電装置トリップ信号発生回路５０の構成を示すブロック図である。It is a block diagram which shows the structure of the power transmission terminal ground fault overcurrent relay apparatus trip signal generation circuit 50 with which the power transmission terminal ground fault overcurrent relay apparatus 11 shown in FIG. 図１に示した第１の受電端地絡方向継電装置２２₁が備える第１の受電端地絡方向継電装置トリップ信号発生回路６０の構成を示すブロック図である。It is a block diagram showing a configuration of a first receiving end earth fault direction relay device trip signal generating circuit 60 to first receiving end earth fault direction relay device 22 ₁ shown in FIG. 1 is provided. 図１に示した第２の受電端地絡方向継電装置２２₂が備える第２の受電端地絡方向継電装置トリップ信号発生回路７０の構成を示すブロック図である。It is a block diagram showing a configuration of a second receiving end earth fault direction relay device trip signal generating circuit 70 in which the second receiving end earth fault direction relay device 22 ₂ shown in FIG. 1 is provided. 図１に示した受電端地絡過電流継電装置１２が備える受電端地絡過電流継電装置トリップ信号発生回路８０の構成を示すブロック図である。FIG. 2 is a block diagram illustrating a configuration of a power receiving terminal ground fault overcurrent relay device trip signal generation circuit 80 included in the power receiving terminal ground fault overcurrent relay device 12 illustrated in FIG. 1. 第１の送電線１Ｌの受電端至近端において地絡事故が発生した場合の図１に示した地絡保護継電システムの動作を説明するためのである。It is for demonstrating operation | movement of the ground fault protection relay system shown in FIG. 1 at the time of a ground fault occurring in the power receiving end close | similar end of 1 L of 1st power transmission lines. 第１の送電線１Ｌの送電端至近端において地絡事故が発生した場合の図１に示した地絡保護継電システムの動作を説明するためのである。It is for demonstrating operation | movement of the ground fault protection relay system shown in FIG. 1 at the time of a ground fault occurring in the power transmission end near 1st transmission line 1L. 主保護として地絡回線選択継電装置を使用するとともに後備保護として地絡方向継電装置を使用した従来の地絡保護継電システムの構成を示す図である。It is a figure which shows the structure of the conventional ground fault protection relay system which uses a ground fault line selection relay apparatus as main protection, and uses a ground fault direction relay apparatus as back-up protection.

Explanation of symbols

３₁〜３₄ 第１乃至第４の零相変流器
４₁〜４₄ 第１乃至第４の遮断器
５₁，５₂ 第１および第２の接地形計器用変圧器
１１送電端地絡過電流継電装置
１２受電端地絡過電流継電装置
２１₁，２１₂ 第１および第２の送電端地絡方向継電装置
２２₁，２２₂ 第１および第２の受電端地絡方向継電装置
３０，４０第１および第２の送電端地絡方向継電装置トリップ信号発生回路
３１，４１，６１，７１リレー判定回路
３２₁〜３２₃，４２₁〜４２₃，６２₁〜６２₃，７２₁〜７２₃ 第１乃至第３の遅延回路
３３，４３，６３，７３論理積回路
３４，４４，６４，７４論理和回路
５０送電端地絡過電流継電装置トリップ信号発生回路
５１，８１地絡事故検出回路
５２₁，５２₂，８２₁，８２₂ 第１および第２の遅延回路
５３₁〜５３₅，８３₁〜８３₅ 第１乃至第５の論理積回路
６０，７０第１および第２の受電端地絡方向継電装置トリップ信号発生回路
８０受電端地絡過電流継電装置トリップ信号発生回路
１１１送電端地絡回線選択継電装置
１１２受電端地絡回線選択継電装置
１２１₁，１２１₂ 第１および第２の送電端地絡方向継電装置
１２２₁，１２２₂ 第１および第２の受電端地絡方向継電装置
１Ｌ，２Ｌ第１および第２の送電線
Ｉ₀₁〜Ｉ₀₄ 第１乃至第４の零相電流
Ｖ_0S 送電端零相電圧
Ｖ_OR 受電端零相電圧
Ｖ_1S 送電端正相電圧
Ｖ_1R 受電端正相電圧
Ｓ₁〜Ｓ₄ 第１乃至第４の事故回線判定結果信号
Ｓ_CB1〜Ｓ_CB4 第１乃至第４の接点信号
Ｓ_OVG1，Ｓ_OVG2 第１および第２のＯＶＧ出力信号
Ｓ_UVG1，Ｓ_UVG2 第１および第２のＵＶＧ出力信号
ＧＴ１₁〜ＧＴ１₄ 第１乃至第４の時限協調時間
ＧＴ２₁〜ＧＴ２₈ 第１乃至第８の零相自由振動誤動作防止時間
ＧＴ３₁〜ＧＴ３₄ 第１乃至第４のＯＶＧ遮断時間
Ｔ_DG1〜Ｔ_DG4 第１乃至第４の地絡方向継電装置トリップ信号
Ｔ_OCG1〜Ｔ_OCG4 第１乃至第４の地絡過電流継電装置トリップ信号 3 _{1 to} 3 ₄ _1st to _4th zero-phase current transformers 4 ₁ to ₄ 4 _1st to _4th circuit breakers 5 ₁ and 5 ₂ 1st and 2nd earthing-type instrument transformer 11 Transmission terminal Fault overcurrent relay device 12 Receiving terminal ground fault overcurrent relay device 21 ₁ , 21 ₂ First and second power transmission terminal ground fault direction relay devices 22 ₁ , 22 ₂ First and second power receiving terminal ground fault direction relay collector 30, 40 first and second sending end ground fault direction relay device trip signal generating circuit 31,41,61,71 relay determining circuit ₃₂₁ _to 323, 42 ₁ to 42 _3, 62 ₁ to 62 ₃ 72 _{1 to} 72 ₃ 1st to 3rd delay circuits 33, 43, 63, 73 AND circuit 34, 44, 64, 74 OR circuit 50 Power transmission terminal ground fault overcurrent relay trip signal generating circuit 51, 81 Ground fault detection circuits 52 ₁ , 52 ₂ , 82 ₁ , 82 ₂ first and second delay circuits 53 _{1 to} 53 ₅ , 8 3 ₁ to 8 ₅ _1st to _5th AND circuits 60 and 70 First and second power receiving terminal ground fault direction relay device trip signal generating circuit 80 Power receiving terminal ground fault overcurrent relay device trip signal generating circuit 111 Terminal ground fault line selection relay device 112 Power receiving terminal ground fault line selection relay device 121 ₁ , 121 ₂ First and second power transmission terminal ground fault direction relay devices 122 ₁ , 122 ₂ First and second power receiving terminals Ground fault direction relay devices 1L, 2L First and second transmission lines I _{01 to} I ₀₄ First to fourth zero phase current V _0S Transmission end zero phase voltage V _OR Reception end zero phase voltage V _1S Transmission end positive phase Voltage V _1R receiving end positive phase voltage S _{1 to} S ₄ first to fourth _fault line determination result signals S _{CB1 to} S _CB4 first to fourth contact signals S _OVG1 , S _OVG2 first and second OVG output signals S _UVG1, S _UVG2 first and second UVG output signal GT1 ₁ ～GT1 ₄ first to fourth timed Adjusting time GT2 ₁ ～GT2 ₈ first to the zero-phase free vibration lockout time GT3 ₁ ～GT3 ₄ first to fourth OVG interruption time T _DG1 through T _DG4 first to fourth ground direction relay eighth Device trip signal T _{OCG1 to} T _OCG4 1st to 4th ground fault overcurrent relay trip signal

Claims

A ground fault protection relay system for protecting a balanced two-line transmission line from a ground fault,
A ground fault overcurrent that is installed in the balanced two-line transmission line and operates based on a difference current between zero-phase currents flowing through the first and second transmission lines (1L, 2L) of the balanced two-line transmission line. A relay device (11; 12);
First and second ground fault direction relay devices (21 ₁ , 21 ₂ ; 22 ₁ , 22 ₂ ) respectively installed on the first and second transmission lines,
When a ground fault occurring in the first transmission line direction is detected in the first ground fault direction relay device and the ground fault is detected also in the ground fault overcurrent relay device, the first transmission line is detected. Outputs a trip signal to shut off the circuit breakers (4 ₁ , 4 ₃ ) installed on the wires,
When the ground fault accident occurring in the second power transmission line direction is detected in the second ground fault direction relay device and the ground fault fault is also detected in the ground fault overcurrent relay device, the second transmission line is detected. Outputs other trip signals to shut off other circuit breakers (4 ₂ , 4 ₄ ) installed on the wires.
A ground fault protection relay system.

A ground fault protection relay system for protecting a balanced two-line transmission line from a ground fault,
A power transmission ground fault overcurrent relay device (11) installed at the power transmission end of the balanced two-line transmission line, and first and second power transmission terminal ground fault direction relay devices (21 ₁ , 21 ₂ ) are provided. ,
When the first power transmission terminal ground fault direction relay device detects that a ground fault has occurred in the first transmission line (1L) direction of the balanced two-line transmission line, a first fault line determination result signal ( _First relay determination means (31) for outputting S ₁ ) to the power transmission ground fault overcurrent relay device;
When the second power transmission terminal ground fault direction relay device detects that a ground fault has occurred in the second transmission line (2L) direction of the balanced two-line transmission line, a second fault line determination result signal ( S ₂ ) comprising second relay determination means (41) for outputting the power transmission terminal ground fault overcurrent relay device;
The power transmission ground fault overcurrent relay device,
The difference current (I ₀₁ − between the first zero-phase current (I ₀₁ ) flowing through the power transmission end of the first power transmission line and the second zero-phase current (I ₀₂ ) flowing through the power transmission end of the second power transmission line A ground fault detection means (51) for detecting the occurrence of a ground fault in the first or second transmission line based on I ₀₂ ),
When the occurrence of a ground fault is detected in the ground fault detection means and the first fault line determination result signal is input from the first power transmission end ground fault relay device, the first power transmission line First ground fault overcurrent relay trip signal for generating a first ground fault overcurrent relay trip signal (T _OCG1 ) for breaking the first circuit breaker (4 ₁ ) installed at the power transmission end of the Generating means (53 ₁ );
When the occurrence of a ground fault is detected by the ground fault detection means and the second fault line determination result signal is input from the second power transmission end ground fault relay device, the second power transmission line Second ground fault overcurrent relay trip signal for generating a second ground fault overcurrent relay trip signal (T _OCG2 ) for breaking the second circuit breaker (4 ₂ ) installed at the power transmission end of Generating means (53 ₂ ),
A ground fault protection relay system.

A power receiving end ground fault overcurrent relay device (12) installed at the power receiving end of the balanced two-line power transmission line, and first and second power receiving end ground fault direction relay devices (22 ₁ , 22 ₂ ) are further provided. And
When the first power receiving end ground fault direction relay device detects that a ground fault has occurred in the first power transmission line direction, a _third fault line determination result signal (S ₃ ) is transmitted to the power receiving end ground fault. A third relay determining means (61) for outputting to the current relay device;
When the second power receiving end ground fault direction relay device detects that a ground fault has occurred in the second power transmission line direction, a _fourth fault line determination result signal (S ₄ ) is transmitted to the power receiving end ground fault. A fourth relay determining means (71) for outputting to the current relay device;
The power receiving terminal ground fault overcurrent relay device,
The difference current between the third zero-phase ground fault current (I ₀₃ ) flowing through the receiving end of the first transmission line and the fourth zero-phase ground fault current (I ₀₄ ) flowing through the receiving end of the second transmission line Another ground fault detection means (81) for detecting the occurrence of a ground fault in the first or second power transmission line based on (I ₀₃ -I ₀₄ );
When the occurrence of a ground fault is detected in the other ground fault detection means and the third fault line determination result signal is input from the first power receiving end ground fault relay device, the first fault A third ground fault overcurrent relay device for generating a third ground fault overcurrent relay trip signal (T _OCG3 ) for breaking a _third circuit breaker (4 ₃ ) installed at the receiving end of the transmission line Trip signal generating means (83 ₁ );
When the occurrence of a ground fault is detected by the ground fault detection means and the fourth fault line determination result signal is input from the second power receiving end ground fault relay device, the second power transmission line fourth breaker (4 ₄₎ fourth ground fault overcurrent relay device trip signal (T _OCG4) fourth ground fault overcurrent relay device trip signal for generating for blocking of which is installed in the receiving end of the Generating means (83 ₂ ),
The ground fault protection relay system according to claim 2, wherein:

The first and second ground fault overcurrent relay trip signal generating means is connected to the first and second ground fault overcurrent relay trip signal generating means on condition that the first and second circuit breakers are not cut off. And means (53 ₃ , 53 ₄ , 53 ₅ ) for generating a second ground fault overcurrent relay trip signal, respectively,
The power receiving end ground fault overcurrent relay device is provided with the third and fourth ground fault overcurrent relay trip signal generating means on the condition that the third and fourth circuit breakers are not cut off. And means (83 ₃ , 83 ₄ , 83 ₅ ) for generating the fourth ground fault overcurrent relay trip signal, respectively.
The ground fault protection relay system according to claim 2 or 3, characterized in that.

A first UVG output signal (S _UVG1 ) indicating that the magnitude of the positive phase voltage (V _1S ) of the power transmission end of the balanced two-line transmission line has become equal to or less than a set value is received by the power transmission end ground fault overcurrent relay device. The first and second ground fault overcurrents are supplied to the first and second ground fault overcurrent relay trip signal generating means on condition that the first short circuit detection ground fault undervoltage relay is not input. Means (53 ₄ , 53 ₅ ) for generating relay device trip signals respectively;
The power receiving end ground fault overcurrent relay device generates a second UVG output signal (S _UVG2 ) indicating that the power receiving end positive phase voltage (V _1R ) of the balanced two-line transmission line is less than a set value. The third and fourth ground fault overcurrents are supplied to the third and fourth ground fault overcurrent relay trip signal generating means on condition that the second short circuit detection ground fault undervoltage relay is not input. Means (83 ₄ , 83 ₅ ) for generating relay device trip signals respectively;
The ground fault protection relay system according to any one of claims 2 to 4, wherein the ground fault protection relay system is characterized.