Simulation on the residual axial magnetic field in vacuum DC interruption based on artificial current zero

Abstract

The residual axial magnetic field (AMF) at current zero, which is caused by large di/dt during the forced current-zero stage of DC interruption based on the technique of artificial current zero, has significant influence on the interruption performance of the vacuum circuit breaker. In this paper, a model of AMF contacts is developed by finite-element-analysis software, Ansys. The eddy current induced in the contacts system is also analyzed by an equivalent circuit. The influence of the frequency of countercurrent on the residual AMF is investigated.