A METHOD OF DISCRIMINATING BETWEEN AN INTERNAL ARC AND A CIRCUIT-BREAKING ARC IN A MEDIUM OR HIGH VOLTAGE CIRCUIT-BREAKER

摘要

The method relates to discriminating between aninternal arc and a circuit-breaking arc established inthe enclosure of a circuit breaker in a bay of a mediumor high voltage metal-clad substation. The appearance ofan internal arc is detected by a protection system whichresponds by transmitting a disengagement order (15) tothe circuit breaker, thereby causing a circuit-breakingarc to appear. The method consists in:[err] continuously measuring the pressure of thedielectric gas inside the enclosure of the circuitbreaker;[err] recording said pressure measurements so that afterthe instant at which the disengagement order (15) istransmitted, it is possible to recover a first pressurevalue measured before said instant; and[err] comparing said first pressure value with a secondpressure value measured after said instant in order toidentify whether the internal arc was struck in saidcircuit breaker enclosure.