Design and analysis of salient pole rotor coil excitation brushless DC motor using in high voltage circuit breaker operating mechanism

This paper presents a novel configuration of high voltage circuit breaker motor operating mechanism - Salient Pole Rotor Coil Excitation Brushless DC Motor Operating Mechanism in order to improve the operating performance of high voltage circuit breaker. There are two double salient pole motor rotor structure and using field coil instead of permanent magnets. This new structure not only simplifies the complexity of the structure of the motor, but also eliminates the insufficiency of the permanent magnet. In regard of the high voltage circuit breaker mechanical requirements, designing the motor´s salient pole structure, matching method, main parameters and operational mode. Analyzing the electromagnetic characteristics, torque and speed characteristic curves in different conditions of the motor by using three-dimensional finite element method. The analysis results indicate that the novel structure motor design is reasonable. It has high starting torque, small torque ripple, good speed expansion capability and favorable field-control performance, and it can provide high mechanical properties that could satisfy the requirement of circuit breaker opening and closing speed. Further provides the reliable theoretical basis for high voltage circuit breaker using motor operating mechanism.