永磁无刷直流电动机结构对转矩脉动的影响

摘要

Torque ripple is one of the main factors that affect the output torque stability and precision of permanent magnet brushless DC motor (BLDCM). Relationship among air gap flux density, EMF and torque ripple was derived according to brushless DC motor structure. The effect of EMF on torque ripple was analyzed. Through finite element analysis method , air gap flux density and torque ripple were analyzed and compared under different magnetized mode and pole arc coefficient. EMF waveform and torque ripple coefficient were calculated. It is significant for permanent magnet BLDCM design.%转矩脉动是影响永磁无刷直流电动机输出力矩稳定性和精度的主要因素之一.针对永磁无刷直流电动机结构,推导了其气隙磁密与反电势和转矩脉动的关系,分析了反电势波形对转矩脉动的影响,采用Ansys对电机永磁体的不同充磁方式和不同极弧系数条件下的气隙磁密和转矩脉动进行了仿真,得到了电机反电势波形并计算得到转矩脉动系数,对于无刷直流电动机的电磁设计具有较好的指导意义.