Protection relay apparatus

摘要

According to one embodiment, there is provided a protection relay apparatus that protects lines of a three-phase alternating current power system, the protection relay apparatus including a fault detector to detect a fault of the line, an opening unit to open a circuit breaker of a fault phase in which the fault has occurred through detection of the fault, a fault phase voltage measurement unit to measure a voltage of the fault phase after the circuit breaker is opened, a fault recovery determination unit to determine whether the fault is recovered or not based on the voltage, and a closing unit to close the circuit breaker when the fault recovery determination unit determines that the fault is recovered.

主权项

1. A protection relay apparatus that protects lines of a three-phase alternating current power system, the protection relay apparatus comprising:
a fault detector configured to detect a fault of a line; an opening unit configured to open a circuit breaker of a fault phase in which the fault has occurred through detection of the fault by the fault detector; a fault phase voltage measurement unit configured to measure a voltage of the fault phase after the circuit breaker is opened by the opening unit; a fault recovery determination unit configured to determine whether the fault is recovered or not based on the voltage measured by the fault phase voltage measurement unit; and a closing unit configured to close the circuit breaker when the fault recovery determination unit determines that the fault is recovered, wherein the fault recovery determination unit determines that the fault is recovered when the voltage measured by the fault phase voltage measurement unit is within a previously set permissible range, and determines that the fault is not recovered when the voltage measured by the fault phase voltage measurement unit is not within a previously set permissible range, after an elapse of a no-voltage confirmation time after the circuit breaker was opened by the opening unit, the closing unit suspends a closing of the circuit breaker when the fault recovery determination unit determines that the fault is not recovered, and the no-voltage confirmation time is a time that is longer than a time to a time point at which it is predicted that a measured voltage of the fault phase becomes constant in a portion near a reference voltage immediately after completion of interruption of the fault phase.