JP2004129465A - Failed line selecting relay apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failed line selecting protective device at a customer receiving end independent of and separated from a protective device at a sending end of an electric power company. <P>SOLUTION: In a failed line selecting relay apparatus for receiving wires of an electric power system, a plurality of receiving lines each comprising a receiving wire and a transformer are operated in parallel. The relay apparatus comprises: a receiving ground fault detecting means which determines a ground fault current from the secondary current of a current transformer connected with each receiving transformer primary neutral phase and compares it with an arbitrarily set value by computation; a receiving line in loop operation detecting means which detects the state of parallel operation of a plurality of the receiving lines from the open/close state of system equipment, such as disconnectors and circuit breakers in the individual receiving lines and buses linking the individual receiving lines; and a line selecting means which selects a ground fault line by the duration of disagreement between the results of receiving ground fault detection on receiving lines in loop operation and the state of respective receiving ground fault detections from detection signals from the individual receiving ground fault detecting means and receiving line in loop operation detecting means. The relay system is constituted with ground fault overcurrent detection as a major element. This facilitates adjustmental testing and maintenance and inspection, and mitigates the skillfulness limitation associated with adjustmental testing and enhances workability. <P>COPYRIGHT: (C)2004,JPO

Description

【００２０】
一方、系統機器５，６，９，１０，１１の各情報は、ループ中検出処理２０で読み込まれる。図１の場合、系統機器５，６，９，１０，１１の全てが閉合の場合にループ運転中と判定する。事故回線判定処理１９の判定結果情報はループ中検出処理２０の判定結果情報とそれぞれ論理積処理２１、２２され、任意の継続時間カウント処理２３、２４を介して事故回線選択の当該受電遮断器５、もしくは当該受電遮断器６に地絡選択遮断指令（トリップ信号）を出力する。
【００２１】
図５を参照して本発明の事故回線選択処理タイムチャートを説明する。
図中、各ブロックに付した図１と同じ符号は、図１の説明と同様である、複数の受電回線は負荷の増大や、受電電源の無停電切替など必要に応じて並列運用される。受電が並列運用されている場合に送電線の事故点４で事故▲１▼が生じると、需要家受電端の並列運用中の全受電変圧器中性点に地絡電流が流れ、全受電回線の地絡事故が検出される▲２▼ａ，▲２▼ｂ。同時に、地絡送電線の電力会社送電端遮断器２経路から流出する過大電流で電力会社送電端保護装置１６が動作して▲２▼、送電端遮断器２を遮断する▲３▼。送電端遮断器２の開放で事故回線の電力会社送電端保護装置１６は復帰し▲４▼、事故点４は需要家の受電変圧器７，８を介して健全側送電経路に接続される。この結果、需要家健全送電線側の受電変圧器８の中性点地絡電流は消滅するが、事故送電線側の受電変圧器７の中性点には事故点４への地絡電流が継続する。
【００２２】
すなわち、送電端遮断器２の開放で需要家の事故側送電線の受電地絡検出１４は継続し、健全側送電線の受電地絡検出は復帰する▲５▼。一方、事故側送電線の受電遮断器は閉合状態であり、当該受電電圧検出も動作継続する。つまり、電力会社の事故送電端遮断器が開放した後は、需要家側系統はループ中検出を継続し、受電事故回線の受電地絡検出も継続、健全側の受電地絡検出は復帰▲５▼し、復帰状態を継続する、従って、図４の事故回線選択処理で説明したように、任意時間ｔｄ後に地絡回線選択遮断指令▲６▼が出力されて需要家の事故受電遮断器５が開放▲７▼し、地絡事故送電線が切り離され▲８▼、需要家のループ中検出も復帰し▲９▼、地絡回線選択指令（１０）も復帰する。
【００２３】
以上説明したように、本発明の回線選択保護装置１８は地絡事故回線選択判定時限ｔｄを極力小さく（受電地絡検出の動作処理―復帰処理に要する時間特性差にマージンを加えた値）整定すれば、電力会社送電端事故遮断に連続した次段（２段）時限保護の事故回線選択遮断を可能にする。
【００２４】
図２は本発明の第２実施形態の受電保護系統図であり、図４は本発明の地絡事故回線選択処理の概要図、図５は本発明による地絡事故回線選択処理のタイムチャートである。
【００２５】
図２において、需要家の電力は電力会社の送電設備１から遮断器２、３を介した複数の送電回線で供給される。需要家では複数の送電回線を受電遮断器５，６及び、それぞれの受電用変圧器７，８、変圧器二次遮断器９，１０を介して需要家母線電圧に降圧して負荷へ供給する。また需要家のそれぞれ受電回線に接続された計器用変流器の二次或いは、三次電流を回線選択保護装置１８に入力して三相ベクトルから生成されるそれぞれの受電回線の零相電流を求め、受電地絡事故検出１４、１５を実行する。また、電力系統機器５，６，９，１０、１１の状態も回線選択保護装置１８に入力し、回線選択情報として処理する。回線選択保護装置１８は受電電力系統機器の状態情報と、受電地絡事故検出１４，１５の動作情報から地絡事故回線の選択処理を実行して事故回線の受電遮断器５、もしくは受電遮断器６に地絡選択遮断指令（トリップ信号）を出力する。
【００２６】
図４を参照して本発明の事故回線選択処理１８の概要を説明する。
図中、各ブロックに付した図２と同じ符号は、図２の説明と同様である、それぞれの受電地絡事故検出１４、１５の動作情報は事故回線判定処理１９で読み込まれ、表２のような回線選択判定を実行する。
【００２７】
【表２】

【００２８】
一方、系統機器５，６，９，１０，１１の各情報は、ループ中検出処理２０で読み込まれる。図２の場合、系統機器５，６，９，１０，１１の全てが閉合の場合にループ運転中と判定する。事故回線判定処理１９の判定結果情報はループ中検出処理２０の判定結果情報とそれぞれ論理積処理２１、２２され、任意の継続時間カウント処理２３、２４を介して事故回線選択の当該受電遮断器５、もしくは当該受電遮断器６に地絡選択遮断指令（トリップ信号）を出力する。
【００２９】
図５を参照して本発明の事故回線選択処理タイムチャートを説明する。
図中、各ブロックに付した図１と同じ符号は、図１の説明と同様である、複数の受電回線は負荷の増大や、受電電源の無停電切替など必要に応じて並列運用される。受電が並列運用されている場合に送電線の事故点４で事故▲１▼が生じたとすると、需要家受電端の並列運用中の全受電変圧器中性点に地絡電流が流れ、全受電回線で地絡事故が検出される▲２▼ａ，▲２▼ｂ。同時に、地絡当該送電線の電力会社送電端遮断器２経路から流出する過大電流で電力会社送電端保護装置１６が動作して▲２▼送電端遮断器２を遮断する▲３▼。送電端遮断器２の開放で事故回線の電力会社送電端保護装置１６は復帰し▲４▼、事故点４は需要家の受電変圧器７，８を介して健全側送電経路に接続される。この結果、需要家健全送電線側の受電変圧器８の中性点地絡電流は消滅するが、事故送電線側の受電変圧器７、の中性点には事故点４への地絡電流が継続する。
【００３０】
すなわち、送電端遮断器２の開放で需要家の事故側送電線の受電地絡検出１４は継続し、健全側送電線の受電地絡検出は復帰する▲５▼。一方、事故側送電線の当該受電遮断器は閉合状態であり、当該受電電圧検出も動作継続である。つまり、電力会社の事故送電端遮断器が開放した後は、需要家側系統はループ中検出を継続し、受電事故回線の受電地絡検出も継続、健全側の受電地絡検出は復帰し▲５▼、復帰状態を継続する、従って、図４の事故回線選択処理で説明したように、任意時間ｔｄ後に地絡回線選択遮断指令▲６▼が出力されて需要家の事故受電遮断器５が開放し▲７▼、短絡事故送電線が切り離され▲８▼、需要家のループ中検出も復帰し▲９▼、短絡回線選択指令（１０）も復帰する。
【００３１】
以上説明したように、本発明の回線選択保護装置１８は地絡事故回線選択判定時限ｔｄを極力小さく（受電地絡検出の動作処理―復帰処理に要する時間特性差にマージンを加えた値）整定すれば、電力会社送電端事故遮断に連続した次段（２段）時限保護の事故回線選択遮断を可能にする。
【００３２】
図３は本発明の第３実施形態の受電保護系統図、図４は本発明の地絡事故回線選択処理の概要図、図５は本発明による地絡事故回線選択処理のタイムチャートである。
【００３３】
図３において、需要家の電力は電力会社の送電設備１から遮断器２、３を介した複数の送電回線で供給される。需要家では複数の送電回線を受電遮断器５，６及び、それぞれの受電用変圧器７，８、変圧器二次遮断器９，１０を介して需要家母線電圧に降圧して負荷へ供給する。また需要家のそれぞれ受電回線に接続された計器用変圧器の二次或いは三次電圧を回線選択保護装置１８に入力して三相ベクトルから生成されるそれぞれの受電回線の零相電圧を求め、受電地絡事故検出１４、１５を実行する。また、電力系統機器５，６，９，１０、１１の状態も回線選択保護装置１８に入力し、回線選択情報として処理する。回線選択保護装置１８は受電電力系統機器の状態情報と、受電地絡事故検出１４，１５の動作情報から地絡事故回線の選択処理を実行して事故回線の受電遮断器５、もしくは受電遮断器６に地絡選択遮断指令（トリップ信号）を出力する。
【００３４】
図４を参照して本発明の事故回線選択処理１８の概要を説明する。
図中、各ブロックに付した図３と同じ符号は、図３の説明と同様である、それぞれの受電地絡事故検出１４、１５の動作情報は事故回線判定処理１９で読み込まれ、表３のような回線選択判定を実行する。
【００３５】
【表３】

【００３６】
一方、系統機器５，６，９，１０，１１の各情報はループ中検出処理２０で読み込まれる。図３の場合、系統機器５，６，９，１０，１１の全てが閉合の場合にループ運転中と判定する。事故回線判定処理１９の判定結果情報はループ中検出処理２０の判定結果情報とそれぞれ論理積処理２１、２２され、任意の継続時間カウント処理２３、２４を介して事故回線選択の当該受電遮断器５、もしくは当該受電遮断器６に地絡選択遮断指令（トリップ信号）を出力する。
【００３７】
図５を参照して本発明の事故回線選択処理タイムチャートを説明する。
図中、各ブロックに付した図３と同じ符号は、図３の説明と同様である、複数の受電回線は負荷の増大や、受電電源の無停電切替など必要に応じて並列運用される。受電が並列運用されている場合に送電線の事故点４で事故▲１▼が生じたとすると、需要家受電端の受電回線に接続された計器用変圧器二次或いは三次電圧の三相ベクトル和に零相電圧が発生し、全受電回線で地絡事故が検出される▲２▼ａ，▲２▼ｂ。同時に、地絡送電線の電力会社送電端の遮断器２経路から流出する過大電流で電力会社送電端保護装置１６が動作して▲２▼送電端遮断器２を遮断する▲３▼。送電端遮断器２の開放で事故回線の電力会社送電端保護装置１６は復帰し▲４▼、事故点４は需要家の受電変圧器７，８を介して健全側送電経路に接続される。この結果、需要家健全送電線側の受電回線に接続された計器用変圧器二次或いは三次電圧の三相ベクトル和の零相電圧は消滅するが、事故送電線側の三相ベクトル和の零相電圧は継続する。
【００３８】
すなわち、送電端遮断器２の開放で需要家の事故側送電線の受電地絡検出１４は継続し、健全側送電線の受電地絡検出１５は復帰する▲５▼。一方、事故側送電線の受電遮断器は閉合状態であり、受電電圧検出も動作継続する。つまり、電力会社の事故送電端遮断器が開放した後は、需要家側系統はループ中検出を継続し、受電事故回線の受電地絡検出も継続、健全側の受電地絡検出は復帰し▲５▼、復帰状態を継続する、従って、図４の事故回線選択処理で説明したように、任意時間ｔｄ後に地絡回線選択遮断指令▲６▼が出力されて需要家の事故受電遮断器５が開放し▲７▼、地絡事故送電線が切り離され▲８▼、需要家のループ中検出も復帰し▲９▼、地絡回線選択指令（１０）も復帰する。
【００３９】
以上説明したように、本発明の回線選択保護装置１８は地絡事故回線選択判定時限ｔｄを極力小さく（受電地絡検出の動作処理―復帰処理に要する時間特性差にマージンを加えた値）整定すれば、電力会社送電端事故遮断に連続した次段（２段）時限保護の事故回線選択遮断を可能にする。
【００４０】
図６は本発明の第４実施形態の短絡事故回線選択処理の概要図、図７は本発明による短絡事故回線選択処理のタイムチャートである。
図１の受電保護系統図において、１号線の４の箇所で短絡事故が発生したとすると、回線選択保護装置１８は受電電力系統機器の状態情報と、受電不足電圧検出１４，１５の動作情報から短絡事故回線の選択処理を実行して事故回線の受電遮断器５、もしくは受電遮断器６に短絡選択遮断指令（トリップ信号）を出力する。
【００４１】
図６を参照して本発明の事故回線選択処理１８の概要を説明する。
図中、各ブロックに付した図１と同じ符号は、図１の説明と同様である、それぞれの受電不測電圧検出１４，１５の動作情報は不一致動作検出処理１９で読み込まれ、表４のような回線選択判定を実行する。
【００４２】
【表４】

【００４３】
一方、系統機器５，６，９，１０，１１の各情報はループ中検出処理２０で読み込まれる。図１の場合、系統機器５，６，９，１０，１１の全てが閉合の場合にループ運転中と判定する。事故回線判定処理１９の判定結果情報はそれぞれループ中検出処理２０の判定結果情報と論理積処理２１、２２され、任意の継続時間カウント処理２３、２４を介して事故回線選択の当該受電遮断器５、もしくは当該受電遮断器６に短絡選択遮断指令（トリップ信号）を出力する。
【００４４】
図７を参照して本発明の事故回線選択処理のタイムチャートを説明する。
図中、各ブロックに付した図１と同じ符号は、図１の説明と同様である、複数の受電回線は負荷の増大や、受電電源の無停電切替など必要に応じて並列運用される。受電が並列運用されている場合に送電線の事故点４で短絡事故▲１▼が生じたとすると、需要家受電端の全受電回線で不足電圧▲２▼ａ，▲２▼ｂが検出され、同時に事故回線の電力会社送電端の遮断器２経路から流出する過大電流で電力会社送電端保護装置１６が動作して▲２▼送電端遮断器２を遮断する▲３▼。送電端遮断器２の開放で事故回線の電力会社送電端保護装置１６は復帰し▲４▼、事故点４に流れる短絡電流は送電端遮断器３と需要家受電端遮断器５の健全回線を迂回する。すなわち、事故電流が受電変圧器７，８を介して流れ、短絡インピーダンスの殆んどを受電変圧器７，８のインピーダンスで占めるので、需要家の健全側受電不足電圧検出も復帰する▲５▼。
【００４５】
一方、事故側送電線の受電遮断器は閉合状態であり、受電電圧検出も動作継続である。つまり、電力会社の事故送電端遮断器が開放した後は、需要家側系統はループ中検出を継続し、受電事故回線の受電不足電圧検出も継続、健全側の受電不足電圧検出は復帰し▲５▼、復帰状態を継続する、従って、図６の事故回線選択処理で説明したように、任意時間ｔｄ後に短絡回線選択遮断指令▲６▼が出力されて需要家の事故当該受電遮断器５が開放し▲７▼、短絡事故送電線が切り離され▲８▼、需要家のループ中検出も復帰し▲９▼、短絡回線選択指令（１０）も復帰する。
【００４６】
以上説明したように、本発明の回線選択保護装置１８は短絡事故回線選択判定時限ｔｄを極力小さく（不足電圧検出の動作処理―復帰処理に要する時間特性差にマージンを加えた値）制定すれば、電力会社送電端事故遮断に連続した次段（２段）時限保護の事故回線選択遮断を可能にする。
【００４７】
【発明の効果】
以上説明したように、本発明によると、電力会社送電端事故遮断に連続した次段（２段）時限保護ができるので、比較的高速度な保護を可能とする他、電力会社送電端保護装置との独立分離構成も可能となるので、保護装置が簡素化し設備工事が大幅に削減できる。更に、基本的な単一特性リレーである地絡過電流検出あるいは不足電圧検出を主要素としているので、調整試験や保守点検が簡単になり、試験調整の熟練制限や作業性の向上も実現できる。
【図面の簡単な説明】
【図１】本発明の第１実施形態の受電保護系統図。
【図２】本発明の第２実施形態の受電保護系統図。
【図３】本発明の第３実施形態の受電保護系統図。
【図４】本発明の地絡事故回線選択処理の概要図。
【図５】図４の事故回線選択処理タイムチャート。
【図６】本発明の第４実施形態の短絡事故回線選択処理の概要図。
【図７】図６の事故回線選択処理タイムチャート。
【図８】従来の受電保護系統図。
【符号の説明】
１…電力会社の送電設備、２…１号送電遮断器、３…２号送電遮断器、４…１号送電線短絡事故点、５…需要家の１号受電遮断器、６…需要家の２号受電遮断器、７…需要家の１号受電変圧器、８…需要家の２号受電変圧器、９…需要家の１号受電変圧器二次遮断器、１０…需要家の２号受電変圧器二次遮断器、１１…需要家の母線遮断器、１２…１号送電線区間保護装置、１３…２号送電線区間保護装置、１４…需要家の１号受電不足電圧検出手段、１５…需要家の２号受電不足電圧検出手段、１６…電力会社の１号送電保護手段、１７…電力会社の２号送電保護手段、１８…本発明の短絡事故回線選択手段、１９…停電受電回線選択手段、２０…受電ループ運用状態検出処理、２１…１号回線事故判定論理積処理、２２…２号回線事故判定論理積処理、２３…１号事故判定遅延処理、２４…２号事故判定遅延処理、２５…１号受電遮断出力、２６…２号受電遮断出力。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an accident line selection and protection device that selects an accident line in a system in which a plurality of power reception lines configured by a power receiving line and a power receiving transformer are operated in parallel by a power receiving transformer secondary.
[0002]
[Prior art]
Provision of multiple distribution lines from transmission lines via multiple transformers, installation of ground fault sequence switches for each distribution line, and test opening timing of the circuit breaker of the own distribution line depending on whether the circuit breaker is conducting By changing the time until the above, the two distribution lines are not interrupted in the same manner, and the distribution line in which the micro ground fault occurs is specified (see Japanese Patent Application Laid-Open No. 9-103026). Alternatively, when a bus ground fault is detected, the bus breaker is opened after a predetermined time, and when the ground fault is no longer detected, the bus breaker is returned to open the protector breaker, and the network bus of the ground fault accident is disconnected. (Refer to Japanese Patent Application Laid-Open No. 11-299087) A technique is known. Further, there is known an accident line selection relay device that selects a ground fault accident line of a system in which a plurality of power receiving lines including a receiving line and a receiving transformer are operated in parallel by a receiving transformer secondary.
[0003]
An accident line selection relay device for selecting such a ground fault accident line will be described with reference to a power receiving protection system diagram of FIG.
The power of the customer is supplied from a power transmission facility 1 of a power company through a plurality of power transmission lines via circuit breakers 2 and 3. The customer steps down the plurality of transmission lines to the customer bus voltage via the power receiving circuit breakers 5 and 6 and the respective power receiving transformers 7 and 8 and the transformer secondary circuit breakers 9 and 10 and supplies the voltage to the load. I do. The plurality of power receiving lines are operated in parallel as needed, such as an increase in load or uninterruptible switching of the power supply. The transmission line accident line selection protection of the system operated in this manner is performed by transmitting protection device information provided as an integrated device at both ends of each transmission line (the transmission end of the power company and the reception end of the customer) as a carrier or A transmission line section protection device that simultaneously shuts off a power company and a customer in cooperation with a pilot wire system is applied.
[0004]
Next, the outline of the accident detection will be described with reference to the power receiving protection system diagram of FIG. For example, assuming that a ground fault has occurred at location 4 of the No. 1 transmission line, a ground fault current flows out of the path of the power company transmission end circuit breaker 2 on the accident line side (ground fault current flows in the direction of the transmission line), and the customer's Also in the path of the receiving end circuit breaker 5, a ground fault current according to the zero-phase impedance distribution flows out to the transmission line via the primary neutral point of the receiving transformer 7. On the other hand, in the path of the power transmission end circuit breaker 3 on the healthy circuit side, a ground fault current according to the zero-phase impedance distribution via the primary neutral point of the receiving transformer 8 of the customer flows in from the transmission line. In other words, the transmission line section protection device simultaneously shuts off both end circuit breakers 2 and 5 of the accidental transmission line when the accident is in the direction of the transmission line by transmitting the accident direction information between the transmission end of the power company and the reception end of the customer. It is configured as follows.
[0005]
Further, for example, if a short circuit accident occurs at the point 4 on the No. 1 transmission line, an excessive current flows out of the path of the circuit breaker 2 at the power transmission end of the power line on the accident line side, and the excess current flows out of the power receiving end circuit breaker 5 of the customer. Also, the fault current according to the fault impedance distribution that bypasses the healthy line flows out, and the section protection devices at both ends of the fault line both shut off both circuit breakers 2 and 5 at the same time by transmitting the transmission line side fault information. It is configured.
[0006]
[Problems to be solved by the invention]
As described above, the conventional faulty line selection protection device has no performance problem, but has the following problems with respect to equipment, cost, adjustment test, maintenance and inspection.
{Circle around (1)} A great burden is placed on the laying work and cost of communication cables, communication devices, etc. that link the protection device information for both sections at the power transmission end and the customer reception end.
{Circle around (2)} In the case of the current-balanced pilot wire method, fine adjustment in combination with both end devices and the actual communication path is required, adjustment tests such as inductance matching and impedance matching are difficult, and skill is required. Potential dangers are that surge and insulation measures may be inadequate.
(3) Periodic inspections for maintaining performance are restricted by the simultaneous execution by the electric power company and the customer side, and this is an increase in maintenance such as inspection of communication cables and communication devices.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide an accident line selection and protection device for a customer receiving terminal which is independently separated from a protection device for a transmitting terminal of a power company.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is an apparatus for selecting a faulty line selection relay device of a power receiving line of a power system in which a plurality of power receiving lines including a power receiving line and a transformer are operated in parallel. A power receiving ground fault detecting means for obtaining a ground fault current from a secondary current of an instrument current transformer connected to a primary neutral phase of a transformer and performing a comparison operation with an arbitrarily set value; Loop operating power receiving line detecting means for detecting a parallel operating state of a plurality of power receiving lines from the open / closed state of system equipment such as a disconnector and a circuit breaker of a bus cooperating with the power receiving lines, the respective power receiving ground fault detecting means and Line selection processing means for selecting a ground fault accident line based on the detection time of the power receiving ground fault detection result during loop operation based on the detection signal of the power receiving ground detection means during loop operation and the respective power receiving ground fault detection states. Characterized in that was.
[0009]
According to claim 1, the ground fault current is obtained from the secondary current of the current transformer for the instrument connected to the primary neutral phase of each power receiving transformer, and the calculated value is compared with an arbitrarily set value to perform a ground fault on the power receiving line. As a result of these detections, if any of the receiving lines is operating in parallel, a mismatch occurs in the detection of the ground fault between the receiving lines, and if this mismatch continues for an arbitrary period of time, the The line is determined to be a ground fault line.
[0010]
The invention according to claim 2 is a faulty line selection relay device for a receiving line of a power system in which a plurality of receiving lines composed of a receiving line and a transformer are operated in parallel, for an instrument connected to each receiving point. A power receiving ground fault detecting means for obtaining a zero-phase current of each power receiving line generated from a three-phase vector of a secondary or tertiary battery of a current transformer and performing a comparison operation with an arbitrarily set value; A loop-operating power receiving line detecting means for detecting a parallel operation state of a plurality of power receiving lines from an open / closed state of a system device such as a disconnector and a circuit breaker of a bus cooperating with each power receiving line, and detecting the respective power receiving ground faults Means for selecting a ground fault accident line according to the duration of the mismatch between the power ground fault detection results during loop operation and the respective power ground fault detection states from the detection signal of the means and the loop power receiving line detection means during loop operation. Characterized by comprising a selecting unit.
[0011]
According to claim 2, the zero-phase current of each power receiving line generated from the three-phase vector of the secondary or tertiary battery of the current transformer for the instrument connected to each power receiving point is determined, and the value is arbitrarily set. A comparison operation is performed to detect the ground fault of the power receiving line.As a result of these detections, when any of the power receiving lines is operated in parallel, a mismatch occurs in the detection of the power ground fault between the power receiving lines. If it continues, the power receiving line on the ground fault detection side is determined to be a ground fault accident line.
[0012]
According to a third aspect of the present invention, there is provided a faulty line selection relay device for a power receiving line of a power system in which a plurality of power receiving lines composed of a power receiving line and a transformer are operated in parallel, for an instrument connected to each power receiving point. A secondary ground of the transformer, a zero-phase voltage of each power receiving circuit generated from a three-phase vector of the tertiary voltage, a power receiving ground fault detecting unit that performs a comparison operation with an arbitrarily set value, and a power receiving ground and Loop receiving power line detection means for detecting a parallel operation state of a plurality of power lines from the open / close state of system equipment such as a disconnector and a circuit breaker of a bus cooperating with each power receiving line, and the respective power receiving ground fault detecting means And a circuit for selecting a ground fault accident line based on the mismatching duration of the power receiving ground fault detection results during loop operation from the detection signal of the loop running power receiving line detecting means and the respective power receiving ground fault detection states. Characterized by comprising a selecting unit.
[0013]
According to the third aspect, the zero-phase voltage of each power receiving circuit generated from the three-phase vector of the secondary or tertiary voltage of the instrument transformer connected to each power receiving point is obtained, and a value set arbitrarily. Performs a comparison operation to detect ground faults in the power receiving line.As a result of these detections, when any of the power receiving lines is operating in parallel, a mismatch occurs in the detection of power ground faults between the power receiving lines, and this mismatch continues for an arbitrary period of time. In this case, the power receiving line on the ground fault detection side is determined to be the ground fault accident line.
[0014]
According to a fourth aspect of the present invention, there is provided a faulty line selection relay device for a power receiving line of a power system in which a plurality of power receiving lines composed of a power receiving line and a transformer are operated in parallel, for an instrument connected to each power receiving point. A voltage value of each power receiving line or an area generated from a three-phase vector is obtained from a secondary voltage of the transformer, and a power receiving voltage detecting unit that performs a comparison operation with an arbitrarily set value, each power receiving line and each power receiving line. A loop-operating power receiving line detecting means for detecting a parallel operation state of a plurality of power receiving lines from an open / close state of a system device such as a disconnector and a circuit breaker of a bus cooperating with the power receiving lines, and the respective power receiving voltage detecting means and the loop Circuit selection for selecting a short circuit fault line from the detection signal of the running power receiving line detection means and the duration of mismatch between the received voltage detection results during loop operation and each received voltage detection result Characterized by comprising a processing unit.
[0015]
According to the fourth aspect, each power receiving undervoltage is detected from the primary voltage of the measuring transformer secondary voltage of each power receiving transformer, and as a result of these detections, when any of the power receiving lines is operated in parallel, the power receiving lines are connected to each other. When a mismatch occurs in the detection of the under-voltage, and the mismatch continues for an arbitrary period of time, the power-receiving line on the under-voltage detection side is determined to be the short-circuit accident line.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a power receiving protection system diagram of a first embodiment of the present invention, FIG. 4 is a schematic diagram of a ground fault accident line selection process of the present invention, and FIG. 5 is a time chart of a ground fault accident line selection process of the present invention. is there.
[0017]
In FIG. 1, power of a customer is supplied from a power transmission facility 1 of a power company through a plurality of power transmission lines via circuit breakers 2 and 3. At the customer, the plurality of power transmission lines are stepped down to the customer bus voltage via the power receiving circuit breakers 5 and 6 and the respective power receiving transformers 7 and 8 and the transformer secondary circuit breakers 9 and 10 to supply power to the load. Supplied. In addition, the secondary current of the current transformer for the instrument, which is installed at the primary neutral point of the transformer of the power receiving line of each customer, is input to the line selection and protection device 18, and the power is received from the ground fault current flowing in the neutral phase of the power receiving transformer. The ground fault detections 14 and 15 are executed. Further, the states of the power system devices 5, 6, 9, 10, and 11 are also input to the line selection protection device 18 and processed as line selection information. The line selection protection device 18 executes a ground fault accident line selection process based on the status information of the receiving power system equipment and the operation information of the power receiving ground fault detections 14 and 15 and executes the power receiving circuit breaker 5 or the power receiving cutoff of the line concerned. And outputs a ground fault selection cutoff command (trip signal) to the switch 6.
[0018]
The outline of the accident line selection processing 18 of the present invention will be described with reference to FIG.
In the figure, the same reference numerals as in FIG. 1 attached to each block are the same as those in FIG. 1, and the operation information of the respective power receiving ground fault detections 14 and 15 is read in the fault line determination processing 19, and Such a line selection determination is executed.
[0019]
[Table 1]

[0020]
On the other hand, each information of the system devices 5, 6, 9, 10, and 11 is read in the loop detection processing 20. In the case of FIG. 1, when all of the system devices 5, 6, 9, 10, 11 are closed, it is determined that the loop operation is being performed. The determination result information of the faulty line determination process 19 is ANDed with the determination result information of the in-loop detection process 20, respectively, 21 and 22. Alternatively, a ground fault selection cutoff command (trip signal) is output to the power receiving circuit breaker 6.
[0021]
With reference to FIG. 5, a description will be given of an accident line selection processing time chart according to the present invention.
In the figure, the same reference numerals as in FIG. 1 attached to each block are the same as those in FIG. 1. A plurality of power receiving lines are operated in parallel as necessary, such as an increase in load or uninterruptible switching of a power supply. If an accident (1) occurs at the fault point 4 of the transmission line when the power receiving is operated in parallel, a ground fault current flows to the neutral point of all the receiving transformers in parallel operation at the customer receiving end, and all the receiving lines (2) a, (2) b where the ground fault is detected. At the same time, the power transmission end protection device 16 operates due to excessive current flowing out of the power transmission end circuit breaker 2 path of the ground fault transmission line (2), and the transmission end breaker 2 is shut off (3). When the transmission end circuit breaker 2 is opened, the transmission end protection device 16 of the power company of the accident line is restored (4), and the accident point 4 is connected to the healthy transmission path via the receiving transformers 7 and 8 of the customer. As a result, the neutral point ground fault current of the receiving transformer 8 on the healthy transmission line side disappears, but the ground fault current to the fault point 4 is stored at the neutral point of the receiving transformer 7 on the faulty transmission line side. continue.
[0022]
That is, when the power transmitting end circuit breaker 2 is opened, the power receiving ground fault detection 14 of the accident side transmission line of the customer continues, and the power receiving ground fault detection of the healthy side transmission line is restored (5). On the other hand, the power receiving circuit breaker of the accident side transmission line is in the closed state, and the power receiving voltage detection also continues to operate. In other words, after the accidental power transmission end circuit breaker of the electric power company is opened, the customer side system continues to detect in the loop, continues to detect the power receiving ground fault of the power receiving accident line, and recovers the normal power receiving ground fault detection. ▼ Then, the return state is continued. Therefore, as described in the accident line selection processing of FIG. 4, the ground fault line selection cutoff command (6) is output after the arbitrary time td, and the accident power receiving circuit breaker 5 of the customer is activated. The line is opened {7}, the ground fault accident transmission line is disconnected {8}, the detection in the loop of the customer is also returned {9}, and the ground fault line selection command (10) is also returned.
[0023]
As described above, the line selection protection device 18 of the present invention sets the ground fault accident line selection determination time limit td as small as possible (a value obtained by adding a margin to the time characteristic difference required for the operation process for power receiving ground fault detection-return process). If this is the case, it is possible to selectively cut off the faulty line for the next-stage (two-stage) timed protection that is continuous with the shutting down of the transmission end at the power company.
[0024]
FIG. 2 is a power receiving protection system diagram according to a second embodiment of the present invention, FIG. 4 is a schematic diagram of a ground fault accident line selection process of the present invention, and FIG. 5 is a time chart of a ground fault accident line selection process according to the present invention. is there.
[0025]
In FIG. 2, the power of the customer is supplied from a power transmission facility 1 of a power company through a plurality of power transmission lines via circuit breakers 2 and 3. At the customer, the plurality of transmission lines are stepped down to the customer bus voltage via the power receiving circuit breakers 5, 6 and the respective power receiving transformers 7, 8, and the transformer secondary circuit breakers 9, 10, and supplied to the load. . Also, the secondary or tertiary current of the current transformer for the instrument connected to the power receiving line of each consumer is input to the line selection and protection device 18 to obtain the zero-phase current of each power receiving line generated from the three-phase vector. , And the power receiving ground fault detections 14 and 15 are executed. Further, the states of the power system devices 5, 6, 9, 10, and 11 are also input to the line selection protection device 18 and processed as line selection information. The line selection protection device 18 executes a ground fault accident line selection process based on the status information of the receiving power system equipment and the operation information of the power receiving ground fault detections 14 and 15 and executes the power receiving circuit breaker 5 or the power receiving circuit breaker for the fault line. 6 outputs a ground fault selection cutoff command (trip signal).
[0026]
The outline of the accident line selection processing 18 of the present invention will be described with reference to FIG.
In the figure, the same reference numerals as in FIG. 2 attached to each block are the same as in the description of FIG. 2. The operation information of the respective power receiving ground fault detections 14 and 15 is read in the fault line determination processing 19, and Such a line selection determination is executed.
[0027]
[Table 2]

[0028]
On the other hand, each information of the system devices 5, 6, 9, 10, and 11 is read in the loop detection processing 20. In the case of FIG. 2, when all the system devices 5, 6, 9, 10, and 11 are closed, it is determined that the loop operation is being performed. The determination result information of the faulty line determination process 19 is ANDed with the determination result information of the in-loop detection process 20, respectively, 21 and 22. Alternatively, a ground fault selection cutoff command (trip signal) is output to the power receiving circuit breaker 6.
[0029]
With reference to FIG. 5, a description will be given of an accident line selection processing time chart according to the present invention.
In the figure, the same reference numerals as in FIG. 1 attached to each block are the same as those in FIG. 1. A plurality of power receiving lines are operated in parallel as necessary, such as an increase in load or uninterruptible switching of a power supply. If an accident (1) occurs at fault point 4 of the transmission line when the power receiving is operated in parallel, a ground fault current flows to the neutral point of all receiving transformers in parallel operation at the customer receiving end, and all power receiving Ground faults are detected on the line (2) a, (2) b. At the same time, the power company transmission end protection device 16 operates due to an excessive current flowing out of the power company transmission end circuit breaker 2 path of the transmission line, and (2) shuts off the transmission end circuit breaker 2 (3). When the transmission end circuit breaker 2 is opened, the transmission end protection device 16 of the power company of the accident line is restored (4), and the accident point 4 is connected to the healthy transmission path via the receiving transformers 7 and 8 of the customer. As a result, the neutral point ground fault current of the receiving transformer 8 on the healthy transmission line side disappears, but the ground fault current to the fault point 4 is detected at the neutral point of the receiving transformer 7 on the faulty transmission line side. Continue.
[0030]
That is, when the power transmitting end circuit breaker 2 is opened, the power receiving ground fault detection 14 of the accident side transmission line of the customer continues, and the power receiving ground fault detection of the healthy side transmission line is restored (5). On the other hand, the power receiving circuit breaker of the accident side transmission line is in the closed state, and the power receiving voltage detection is also in operation. In other words, after the open circuit breaker at the transmission end of the power company is opened, the customer side system continues to detect in the loop, the ground fault detection of the faulty power line continues, and the ground fault detection on the healthy side recovers. 5), the return state is continued. Therefore, as described in the accident line selection process of FIG. 4, the ground fault line selection cutoff command (6) is output after an arbitrary time td, and the accident reception circuit breaker 5 of the customer is activated. When the line is opened [7], the short-circuit accident transmission line is disconnected [8], the in-loop detection of the consumer is restored, [9], and the short-circuit selection command (10) is also restored.
[0031]
As described above, the line selection protection device 18 of the present invention sets the ground fault accident line selection determination time limit td as small as possible (a value obtained by adding a margin to the time characteristic difference required for the operation process for power receiving ground fault detection-return process). If this is the case, it is possible to selectively cut off the faulty line for the next-stage (two-stage) timed protection that is continuous with the shutting down of the transmission end at the power company.
[0032]
FIG. 3 is a power receiving protection system diagram according to the third embodiment of the present invention, FIG. 4 is a schematic diagram of a ground fault accident line selection process of the present invention, and FIG. 5 is a time chart of a ground fault accident line selection process according to the present invention.
[0033]
In FIG. 3, power of a customer is supplied from a power transmission facility 1 of a power company via a plurality of power transmission lines via circuit breakers 2 and 3. At the customer, the plurality of transmission lines are stepped down to the customer bus voltage via the power receiving circuit breakers 5, 6 and the respective power receiving transformers 7, 8, and the transformer secondary circuit breakers 9, 10, and supplied to the load. . Also, the secondary or tertiary voltage of the instrument transformer connected to each of the power receiving lines of the consumer is input to the line selection and protection device 18 to determine the zero-phase voltage of each of the power receiving lines generated from the three-phase vector. The ground fault detections 14 and 15 are executed. Further, the states of the power system devices 5, 6, 9, 10, and 11 are also input to the line selection protection device 18 and processed as line selection information. The line selection protection device 18 executes a ground fault accident line selection process based on the status information of the receiving power system equipment and the operation information of the power receiving ground fault detections 14 and 15 and executes the power receiving circuit breaker 5 or the power receiving circuit breaker for the fault line. 6 outputs a ground fault selection cutoff command (trip signal).
[0034]
The outline of the accident line selection processing 18 of the present invention will be described with reference to FIG.
In the figure, the same reference numerals as in FIG. 3 attached to each block are the same as in the description of FIG. 3. The operation information of the respective power receiving ground fault detections 14 and 15 is read in the fault line determination processing 19, and Such a line selection determination is executed.
[0035]
[Table 3]

[0036]
On the other hand, each information of the system devices 5, 6, 9, 10, 11 is read in the in-loop detection processing 20. In the case of FIG. 3, when all of the system devices 5, 6, 9, 10, and 11 are closed, it is determined that the loop operation is being performed. The determination result information of the faulty line determination process 19 is ANDed with the determination result information of the in-loop detection process 20, respectively, 21 and 22. Alternatively, a ground fault selection cutoff command (trip signal) is output to the power receiving circuit breaker 6.
[0037]
With reference to FIG. 5, a description will be given of an accident line selection processing time chart according to the present invention.
In the figure, the same reference numerals as in FIG. 3 attached to each block are the same as those in FIG. 3. A plurality of power receiving lines are operated in parallel as necessary, such as an increase in load or uninterruptible switching of the power receiving power supply. If an accident (1) occurs at the fault point 4 of the transmission line when the power reception is operated in parallel, the three-phase vector sum of the secondary or tertiary voltage of the instrument transformer connected to the power receiving line at the customer receiving end , A ground fault is detected in all power receiving lines (2) a, (2) b. At the same time, the power company transmission end protection device 16 operates with excessive current flowing out of the circuit breaker 2 path of the power company transmission end of the ground fault transmission line, and (2) shuts off the transmission end breaker 2 (3). When the transmission end circuit breaker 2 is opened, the transmission end protection device 16 of the power company of the accident line is restored (4), and the accident point 4 is connected to the healthy transmission path via the receiving transformers 7 and 8 of the customer. As a result, the zero-phase voltage of the three-phase vector sum of the secondary or tertiary voltage of the instrument transformer connected to the power receiving line of the healthy customer transmission line disappears, but the zero-phase voltage of the three-phase vector sum of the accident transmission line side disappears. The phase voltage continues.
[0038]
That is, when the power transmitting end circuit breaker 2 is opened, the power receiving ground fault detection 14 of the accident side transmission line of the customer continues, and the power receiving ground fault detection 15 of the healthy side transmission line is restored (5). On the other hand, the power receiving circuit breaker of the accident side transmission line is in the closed state, and the receiving voltage detection continues to operate. In other words, after the open circuit breaker at the transmission end of the power company is opened, the customer side system continues to detect in the loop, the ground fault detection of the faulty power line continues, and the ground fault detection on the healthy side recovers. 5), the return state is continued, and therefore, as described in the accident line selection processing of FIG. 4, the ground fault line selection cutoff command (6) is output after the arbitrary time td, and the customer's accident power receiving circuit breaker 5 is activated. When the line is opened [7], the ground fault accident transmission line is disconnected [8], the detection in the customer loop is also returned [9], and the ground fault line selection command (10) is also returned.
[0039]
As described above, the line selection protection device 18 of the present invention sets the ground fault accident line selection determination time limit td as small as possible (a value obtained by adding a margin to the time characteristic difference required for the operation process for power receiving ground fault detection-return process). If this is the case, it is possible to selectively cut off the faulty line for the next-stage (two-stage) timed protection that is continuous with the shutting down of the transmission end at the power company.
[0040]
FIG. 6 is a schematic diagram of the short circuit fault line selection processing according to the fourth embodiment of the present invention, and FIG. 7 is a time chart of the short circuit fault line selection processing according to the present invention.
In the power receiving protection system diagram of FIG. 1, if a short-circuit accident occurs at a location 4 on line 1, the line selection protection device 18 obtains from the status information of the power receiving power system equipment and the operation information of the power receiving undervoltage detection 14 and 15. A short-circuit faulty line selection process is executed, and a short-circuiting selection cutoff command (trip signal) is output to the power receiving circuit breaker 5 or the power receiving circuit breaker 6 of the faulty line.
[0041]
The outline of the accident line selection processing 18 of the present invention will be described with reference to FIG.
In the figure, the same reference numerals as in FIG. 1 attached to each block are the same as in the description of FIG. 1, and the operation information of the respective power reception unexpected voltage detections 14 and 15 is read in the mismatch operation detection processing 19, as shown in Table 4. Perform a proper line selection decision.
[0042]
[Table 4]

[0043]
On the other hand, each information of the system devices 5, 6, 9, 10, 11 is read in the in-loop detection processing 20. In the case of FIG. 1, when all of the system devices 5, 6, 9, 10, 11 are closed, it is determined that the loop operation is being performed. The determination result information of the faulty line determination process 19 is ANDed with the determination result information of the in-loop detection process 20, respectively, 21 and 22. Alternatively, a short-circuit selection cutoff command (trip signal) is output to the power receiving circuit breaker 6.
[0044]
A time chart of the accident line selection processing of the present invention will be described with reference to FIG.
In the figure, the same reference numerals as in FIG. 1 attached to each block are the same as those in FIG. 1. A plurality of power receiving lines are operated in parallel as necessary, such as an increase in load or uninterruptible switching of a power supply. Assuming that short-circuit accident (1) occurs at fault point 4 of the transmission line when power reception is operated in parallel, undervoltages (2) a and (2) b are detected in all power receiving lines at the customer receiving end, At the same time, the excess current flowing out of the circuit breaker 2 path at the power transmission end of the accident line causes the power transmission end protection device 16 to operate to cut off the power transmission end breaker 2. When the transmission end circuit breaker 2 is opened, the power company transmission end protection device 16 of the accident line recovers (4), and the short-circuit current flowing to the accident point 4 causes the healthy line of the transmission end circuit breaker 3 and the customer reception end circuit breaker 5 to pass. Make a detour. That is, since the fault current flows through the power receiving transformers 7 and 8 and most of the short-circuit impedance is occupied by the impedance of the power receiving transformers 7 and 8, the detection of the power receiving undervoltage on the healthy side of the consumer is also restored (5). .
[0045]
On the other hand, the power receiving circuit breaker of the accident side transmission line is in the closed state, and the operation of the receiving voltage detection is continued. In other words, after the open circuit breaker at the transmission end of the power company is opened, the customer side system continues to detect the loop, the undervoltage detection of the power failure line continues, and the undervoltage detection of the healthy side recovers. 5), the return state is continued. Therefore, as described in the accident line selection processing of FIG. 6, after a given time td, the short circuit selection / disconnection command (6) is output, and the power-supply breaker 5 of the customer accident is output. When the line is opened [7], the short-circuit accident transmission line is disconnected [8], the in-loop detection of the consumer is restored, [9], and the short-circuit selection command (10) is also restored.
[0046]
As described above, the line selection and protection device 18 of the present invention can minimize the short-circuit fault line selection determination time limit td (the value obtained by adding a margin to the time characteristic difference required for the operation process of undervoltage detection-return process). In addition, it is possible to selectively cut off the faulty line of the next-stage (two-stage) time protection that is continuous with the shutting down of the transmission end at the power company.
[0047]
【The invention's effect】
As described above, according to the present invention, the next-stage (two-stage) time period protection that is continuous with the interruption of the transmission end of the transmission end of the electric power company can be performed, so that relatively high-speed protection can be performed. The protection device can be simplified and the construction work can be greatly reduced. Further, since the detection of the ground fault overcurrent or the detection of the undervoltage, which is a basic single characteristic relay, is a main element, the adjustment test and the maintenance and inspection are simplified, the skill of the test adjustment is restricted, and the workability can be improved.
[Brief description of the drawings]
FIG. 1 is a power receiving protection system diagram according to a first embodiment of the present invention.
FIG. 2 is a power receiving protection system diagram according to a second embodiment of the present invention.
FIG. 3 is a power receiving protection system diagram according to a third embodiment of the present invention.
FIG. 4 is a schematic diagram of a ground fault accident line selection process of the present invention.
FIG. 5 is a time chart of an accident line selection process in FIG. 4;
FIG. 6 is a schematic diagram of a short circuit fault line selection process according to a fourth embodiment of the present invention.
FIG. 7 is a time chart of the accident line selection processing of FIG. 6;
FIG. 8 is a conventional power receiving protection system diagram.
[Explanation of symbols]
1 ... power transmission equipment of a power company, 2 ... transmission breaker of No. 3, 3 ... transmission breaker of No. 4, 4 ... short-circuit accident point of transmission line, 5 ... customer's No. 1 power receiving breaker, 6 ... of customer No.2 power receiving circuit breaker, 7 ... Consumer No.1 power receiving transformer, 8 ... Consumer No.2 power receiving transformer, 9 ... Consumer No.1 power receiving transformer secondary circuit breaker, 10 ... Consumer No.2 Power receiving transformer secondary circuit breaker, 11: customer bus breaker, 12: 1 transmission line section protection device, 13: 2 transmission line section protection device, 14: customer No. 1 power receiving undervoltage detection means, 15 ... Consumer's No. 2 power receiving undervoltage detecting means, 16 ... Power company's No. 1 power transmission protection means, 17 ... Power company's No. 2 power transmission protection means, 18 ... Short circuit accident line selection means of the present invention, 19 ... Power outage receiving power Line selection means, 20: Power receiving loop operation status detection processing, 21: No. 1 line fault judgment logical AND process, 22: No. 2 line fault judgment Logical processing, 23 ... 1 Accident determination delay process, 24 ... 2 Accident determination delay process, 25 ... 1 No. powered cutoff output, 26 ... 2 No. receiving blocking output.

Claims (4)

The fault line selection relay of the receiving line of the power system that operates multiple receiving lines consisting of the receiving line and the transformer in parallel, the current transformer for the instrument connected to the primary neutral phase of each receiving transformer A power receiving ground fault detecting means for obtaining a ground fault current from the secondary current and performing a comparison operation with an arbitrarily set value, and a system such as a disconnector and a circuit breaker of each power receiving line and a bus cooperating with each power receiving line. Loop operating power receiving line detecting means for detecting a parallel operating state of a plurality of power receiving lines from the open / closed state of the devices; and loop operating based on detection signals of the respective power receiving ground fault detecting means and the loop operating power receiving line detecting means. 2. An accident line selection relay device comprising: line selection processing means for selecting a ground fault accident line based on the mismatched continuation time of the power reception ground fault detection result and the respective power reception ground fault detection states. In a ground fault accident line selection relay device of a receiving line of a power system that operates a plurality of receiving lines composed of receiving lines and transformers in parallel, the secondary or secondary of a current transformer for an instrument connected to each receiving point The power receiving ground detection means for obtaining the zero-phase current of each power receiving line generated from the three-phase vector of the tertiary battery, performing a comparison operation with an arbitrarily set value, and connecting each power receiving line and each power receiving line to each other. A loop operating power receiving line detecting means for detecting a parallel operating state of a plurality of power receiving lines from an open / close state of a system device such as a disconnecting switch and a circuit breaker of a cooperating bus, the respective power receiving ground fault detecting means and the loop operating power receiving Line selection processing means for selecting a ground fault accident line based on the duration of mismatch between the power receiving ground fault detection results during loop operation from the detection signal of the line detecting means and the respective power receiving ground fault detection states Accident line selection relay device, characterized in that. In a ground fault accident line selection relay device of the receiving line of the power system that operates a plurality of receiving lines composed of the receiving line and the transformer in parallel, the secondary or the instrument transformer connected to each receiving point, The power receiving ground fault detecting means that obtains the zero-phase voltage of each power receiving circuit generated from the three-phase vector of the tertiary voltage and performs a comparison operation with an arbitrarily set value is linked to each power receiving line and each power receiving line. Loop operating power line detecting means for detecting a parallel operating state of a plurality of power receiving lines from the open / close state of system devices such as a disconnector and a circuit breaker of a bus, and the respective power receiving ground fault detecting means and the loop operating power receiving line Line selection processing means for selecting a ground fault accident line based on the duration of mismatch between the power ground fault detection results during loop operation from the detection signal of the detection means and the respective power ground fault detection states Accident line selection relay device, characterized in that. In a power system that operates multiple power receiving lines consisting of a power receiving line and a transformer in parallel, a short-circuit fault line selection of the power receiving line is performed.From the secondary voltage of the instrument transformer connected to each power receiving point, The voltage value of the receiving line or the area generated from the three-phase vector is determined, a receiving voltage detecting means for performing a comparison operation with an arbitrarily set value, and a bus for cooperating the respective receiving lines and the respective receiving lines. Loop operating power line detection means for detecting a parallel operation state of a plurality of power receiving lines from the open / close state of system devices such as disconnectors and circuit breakers, and detection of the respective power receiving voltage detecting means and the loop power receiving line detecting means. Line selection processing means for selecting a short-circuit fault line from the received signal voltage detection results of the mismatch between the received voltage detection results during loop operation from the signals and the respective received voltage detection results. Accident line selection relay device according to claim.

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