永磁无刷直流电机换相控制研究

Commutation Control of Permanent Brushless DC Motors

永磁无刷直流电机具有结构简单、转矩大等显著优点,然而电机的换相过程会引起转矩波动增大、平均转矩下降等许多问题,随着电机速度的增加,这些问题会变得更为突出。根据电机及逆变器的等效模型推导了变速度条件下最佳提前换相角(时间)的解析公式。在Saber Simulator与Simulink联合仿真环境中建立了无刷直流电机的换相控制模型,并对算法进行验证。结果表明,利用该公式对提前换相时间进行控制后,对克服平均转矩随速度增大而下降的问题有显著效果。

Permanent magnet brushless DC motors （PMBLDCM） have simple structure and great torque. However some problems such as torque ripple increasing and average torque descending can be caused by phase commutation of the motor and may get even worse with the speed increasing. A formula for computing the optimal lead angle at various speeds was derived from the equivalent model of a motor and inverter system. A co-simulation model of motor commutation was constructed with Saber Simulator and Simulink to testify the algorithm. The results show that average torque descending can be diminished evidently by controlling the optimal lead angle.