双凸极永磁电动机磁阻转矩和转矩脉动的关系研究

Research on Relationship Between Reluctant Torque and Torque Ripple for Doubly Salient Permanent Magnet Motor

目前针对双凸极永磁电机的转矩脉动,研究工作主要集中在对换相引起的转矩脉动进行消除和抑制。考虑到双凸极永磁电机一个显著特点是电磁转矩为磁阻转矩和永磁转矩的耦合,所以从磁阻转矩的角度来分析双凸极永磁电机的转矩脉动。建立一台12/8极双凸极永磁电动机的数学模型,并通过有限元计算得出其静态参数。在此基础上通过不同电流、不同转速下多种仿真结果得出磁阻转矩对电机电磁转矩的脉动影响随着电机负载的增加成正比增加,并提出通过合理选择定转子极弧长度及磁钢参数来减小磁阻转矩、增加永磁转矩,最终减小磁阻转矩对电机转矩脉动的影响。仿真结果验证了所提出的方法。

Regarding torque ripple of doubly salient permanent magnet motor （DSPM）, research works concentrate on elimination and restraint of torque ripple caused by commutating. Considering remarkable trait for DSPM that electromagnetic torque is resultant interaction of reluctant torque and permanent magnetic torque, the torque ripple for DSPM was analyzed in the view of reluctant torque. The mathematical model for DSPM with 12/8 poles was established and its static parameters were achieved by finite element calculation. Then the conclusion that torque ripple rate for DSPM caused by reluctant torque ascends with the motor load increase is obtained. Further we propose proper length of stator and rotor pole arc as well as alnico parameters for the purpose of reducing reluctant torque and enhancing permanent magnetic torque, ultimately achieving less contribution to torque ripple from reluctant torque. The simulation result validates the proposed method.