Research on permanent magnetic actuator characteristics considering eddy current effect

Due to short working hours and high action speed, the permanent magnetic actuator of high voltage circuit breaker would generate eddy current in the dynamic and static iron core when it was working. The eddy current would weaken magnetic field of the permanent magnet, which had a great impact on the characteristics of actuator. The coupling method was used to analyze the transient magnetic field of permanent magnetic actuator, the transient magnetic field supplied by voltage was studied and the mathematical model of the nonlinear transient magnetic field was deduced considering the impact of eddy current. Finite element software Ansoft was used to simulate the square permanent magnetic actuator. The influence of eddy current on the characteristics of permanent magnetic actuator was analyzed and studied, and its loss was calculated and analyzed. The changes of electromagnetic force, speed, action time and other parameters of permanent magnetic actuator with different materials and structures was comparative analyzed. The calculation results show that the action time of permanent magnetic actuator will increase for the effect of eddy current. In the operational process of permanent magnetic actuator, the eddy current loss of the dynamic and static iron core is great. At the same time the rational design of the dynamic and static iron core can also greatly reduce the eddy current loss. The study of permanent magnetic actuator´s characteristics taking the influence of eddy current into account can provide theoretical basis for its reasonable design.