Numerical Analysis for Transient Electromagnetic Field of Permanent Magnet Brushless DC Motor

A novel motor operating mechanism is presented which applied in the high voltage circuit breaker. The new motor is a permanent magnet motor with limited angle and only working in the starting stage. Based on the operation requirement of high voltage circuit breaker, the structure and parameters of motor are designed, including the rotor and stator structure, electric load, magnetic load, number of pole pair, air-gap, pole-arc coefficient and etc. The magnetic field analysis and dynamic simulation of motor operating mechanism is achieved by employing the finite element method. The dynamic parameters of motor, such as the torque, current, speed and location is obtained. Finally, the opening and closing stroke curve of moving contact is obtained through the performance testing with the circuit breaker. The results indicate that the motor operating mechanism have a good mechanical characteristics and reach the operation of high voltage circuit breaker.