TRANSMISSION LINE PROTECTION DEVICE, AND TRANSMISSION LINE PROTECTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To make the interruption time identical to a one stage settling time (instantaneous) by automatically changing to the settling for trial charge, when the operation of a transmission protective device is detected to cover the whole transmission line.SOLUTION: A backup protection unit 13Adetects short circuit corresponding to the direction distance of a transmission line 1 on the basis of the voltage and current detected therefrom, and outputs a trip command to a circuit breaker CB provided in the transmission line 1 after predetermined latency when short circuit of the transmission line 1 is detected. When the trip command is outputted, a direction distance relay processing unit 44S is controlled so as to maximize the direction distance, and a direction distance relay processing timer unit 44T is controlled so that a predetermined latency becomes zero when short circuit is detected. When a predetermined time of 60 sec elapses after this control, trial charge of the transmission line is allowed.