Optimization Design of a Permanent Magnet Actuator for 126-kV Vacuum Circuit Breaker

To satisfy the fast operating requirements for 126-kV vacuum circuit breakers (VCBs), this paper proposes a novel monostable permanent magnet actuator (PMA) with separated magnetic circuits and investigates its optimal design method. The proposed PMA is featured with an external disc spring and an auxiliary breaking coil, which helps to realize fast breaking operation. A multistep optimization method is adopted to divide the whole optimization procedure into three suboptimization modules, including the optimizations of PM holding mechanism, breaking spring mechanism, and closing driving mechanism. The optimization results show that the overall performance improvements can be achieved with relatively less computer resources. Experimental results on the prototype validate the applicability of the PMA on 126-kV VCB and the effectiveness of the optimization method.