GROUND FAULT PROTECTION RELAY SYSTEM

To provide a ground fault protection relay system that enables instantaneous interruption during pressurization.SOLUTION: A ground fault protection relay system that is installed and used at an electric station where a power line 110 is connected to a bus 100 and a circuit breaker 130 is provided on the power line 110 and transmits a break signal to the circuit breaker 130 to perform the break operation includes a time saving circuit that generates a shutoff signal and outputs the shutoff signal to the circuit breaker 130 when the circuit breaker 130 is in the on state, and an undervoltage relay (27) 50 detects an undervoltage on the power line 110 on the local line side in a case in which a ground direction relay (67G) 20 detects a ground fault that has continued to occur on the power line 110 on the local line side of the electric station and a ground overvoltage relay (64V) 30 detects an overvoltage of zero phase voltage of the bus 100 after the operation of the ground fault protection relay system due to the ground fault.SELECTED DRAWING: Figure 1 【課題】 加圧時の瞬時の遮断を可能にする地絡保護継電システムを提供する。【解決手段】 母線１００に電力線１１０が接続されていると共に電力線１１０に遮断器１３０が設けられている電気所に設置されて用いられ、切動作を行うための遮断信号を遮断器１３０に送る地絡保護継電システムにおいて、地絡故障による地絡保護継電システム動作後、地絡方向継電器（６７Ｇ）２０が電気所の自回線側の電力線１１０に発生継続した地絡故障を検出すると共に、地絡過電圧継電器（６４Ｖ）３０が母線１００の零相電圧の過電圧を検出した場合に、遮断器１３０が入状態にあり、かつ、自回線側の電力線１１０の電圧不足を不足電圧継電器（２７）５０が検出すると遮断信号を生成し、この遮断信号を遮断器１３０に出力する時間短縮回路を備える。【選択図】 図１