An improved approach to calculate the dynamic characteristics of permanent magnetic actuator of vacuum circuit breaker

In this paper, a new approach to calculate the dynamic characteristics of permanent magnetic actuator (PMA) is presented. In the calculated model, the operational power supply of both coils are offered by the capacitors charged in advance and are controlled respectively by silicon controlled rectifier (SCR). The finite element method (FEM) is used to calculate the static magnetic field. Because the dynamic characteristics of PMA are affected by permanent magnet and exciting current, new mathematics model and equations are established. To solve the equations, a series of iterative process have to be done, so much CPU time is spent. In order to reduce the CPU time, a new process method is introduced in this paper. In the end, the curve of exciting current, moving-core velocity, and voltage of the capacitor are obtained.