Passing the electromotive circuit overcurrent relay where at the unnecessary operational prevention device null transformer substation

摘要

PROBLEM TO BE SOLVED: To prevent a breaker of a substation from being shut off by a ground fault accident in the area under the control of an adjacent substation, in a direct current electric railway.;SOLUTION: It is so arranged that an electrical discharge gap 3 is provided between a rail 21 and a ground mat 23, a return feeder overcurrent relay 2 is provided in a return feeder 27, and furthermore an interruption controller 1 is provided which breaks an AC breaker 6 and DC breakers 10, 11, 12, 13 only when both a discharge detection signal from the electrical discharge gap 3 and a ground fault detection signal from the return feeder overcurrent relay 2 are received simultaneously, and which breaks, when a stringing ground fault signal is received from any of the feeding circuit overcurrent relays 14, 15, 16, 17, only the DC breaker that feeds power to that stringing on which the ground fault has occurred, irrespective of presence or absence of any other detection signal, and which does not interrupt the breaker in other conditions.;COPYRIGHT: (C)2003,JPO