REVERSE POWER PROTECTION METHOD FOR NETWORK POWER DISTRIBUTION

摘要

PURPOSE: To enhance the reliability of prevention and protection of reversed power by opening with a breaker the output from a power distribution line at the low voltage side of a transformer for stepping down the high voltage to the low voltage when more than 1 of relay outputs and breaker operation outputs have changed. ;CONSTITUTION: This method comprises at least a vacuum breaker 1 installed at a branch point of a power distribution line B at high voltage side, an overcurrent relay 2, ground fault direction relay 3, and an undervoltage relay 9 installed at the power distribution line C at low voltage side. When the outputs of all the relays of the overcurrent relay 2, ground fault direction relay 3 and undervoltage relay 9 and more than one operation output of the vacuum breaker 1 are operated, the power distribution line C at low voltage side of a transformer 6 for stepping down the high voltage to low one is opened in an air circuit breaker 10. Then, at the time of outputting from the undervoltage relay 9, the closing of the air circuit breaker installed to the low voltage power distribution line C is prevented, and the ingress of reverse power from the power distribution line C at low voltage side to the power distribution line B at high voltage side can be prevented. By doing this, the reverse power protection for network power distribution can be realized without using network relays.;COPYRIGHT: (C)1993,JPO&Japio