Influence of Different Magnetic Materials on Magnetizing Current and Speed Characteristic of Permanent Magnetic Actuator

In order to improve the performance of circuit-breakers, the influence of different magnetic materials on permanent magnetic actuators´(PMA) exciting current and operating characteristics are researched, and the finite element method(FEM) is used to establish the electromagnetic-mechanical coupled model. The electromagnetic equation, electrical equation and motion equation are solved to study dynamic characteristics of PMA. The yoke iron of PMA is made of cold-rolled silicon steel sheet and electrical pure iron respectively, the curves of the PMA parameters changing with time are obtained. The results show that the PMA with cold-rolled silicon steel sheet has better speed performance and less eddy current loss. A vacuum circuit-breaker with cold-rolled silicon steel sheet PMA is carried out, and in the corresponding experiments the operating characteristics are measured and the exciting current curves are also obtained. It is confirmed that the simulation results are accurate and have a certain actual significance.