GROUND FAULT DETECTION METHOD AND DEVICE USING POSITIVE-PHASE, ONE-PHASE VOLTAGE

摘要

PROBLEM TO BE SOLVED: To detect a ground fault even at an electric power station where only an instrument transformer for one phase is installed, for example, a one-line power receiving station, an individual power receiving station, etc.SOLUTION: A method includes: determining whether a detected value of an instrument transformer which detects only a voltage of one positive phase exceeds a predetermined threshold (step S101); determining whether an operation signal is received from a deficient voltage relay which is installed not at an electric station, but on a consumer side and outputs the operation signal on detecting a two-phase or three-phase deficient voltage (step S103, step S104); determining that a ground fault occurs when the operation signal is not received from the deficient voltage relay (step S105, step S106); and making a display indicating that the occurrence of the ground fault is determined on, for example, a display unit (step S107).