A new concept in post-arc analysis applied to power circuit-breakers

A computer-aided technique that provides an adequate model of the post-arc resistance of circuit breakers is reported. It is based mainly on precise measurement of post-arc current and appropriate representation of arc resistance using a modified Mayr model in which the parameters are evaluated from test data by dedicated computer software. Successfully used to predict failures during the thermal-recovery period on full-sized 200 kV air-blast and SF/sub 6/ circuit breakers, this technique promises to provide valuable assistance in circuit-breaker development. >