Modeling and failure analysis of a permanent magnet vacuum circuit breaker

Vacuum circuit breaker is a key equipment of medium-voltage distribution network, its operational reliability is crucial to the safety of the distribution network. Because of the structural and electrical complexity of vacuum circuit breaker, how to accurately evaluate its working performance by a small number of running parameters, e. g. the time-travel curve of moving contact obtained by online monitoring, is a problem of much concern. In this paper, a permanent magnet vacuum circuit breaker manufactured by XJ Croup Corporation is studied. The software ADAMS and ANSOFT is used for modeling, and the relationship among electrical characteristics, force characteristics and mechanical motion characteristics is unraveled. Accordingly, the method and criteria for mechanical performance evaluation of the circuit breaker are put forward by using the angular displacement curve of principle axis and the current waveform of permanent magnet coil obtained by online monitoring system.