一种抑制盘式永磁电机转矩脉动的方法

Optimization of Torque Ripple Suppression for Disc Permanent Magnet Motor

针对盘式永磁电机气隙磁密和反电动势中含有谐波、存在转矩脉动的问题,提出了一种磁极形状优化方法以降低盘式永磁电机气隙磁密波形和反电动势波形的畸变率、抑制转矩脉动。建立了盘式永磁电机的等效磁网络模型,基于此模型解析计算出电机的空载反电动势,并通过有限元法进行了仿真验证。在确定最小气隙长度前提下,对不同磁极整形方法(即不整形、圆弧削极、偏心圆弧削极)气隙磁密、反电势、转矩脉动这些电磁性能进行了比较,得出了最佳优化方案。结果表明,优化设计后,气隙磁密波形和反电动势波形的畸变率明显减小,转矩脉动得到抑制。

A method of magnetic pole shape optimization was proposed to reduce the sine distortion rate of air gap flux density waveand back-EMF wave and suppress the torque ripple due to the harmonics problem existing in the air gap flux density and back-EMF and the torque ripple existing in disc permanent magnet motor.The analytical expression of back-EMF of the machine was obtained byestablishing the equivalent magnetic network model and verified by FEM.Under the premise of determining the minimum length ofair gap,quantitative comparisons between different magnet shaping methods,i.e.,without shaping,arc shaping,eccentric arc shaping,on electromagnetic performance including air gap flux density,back-EMF and torque ripple were carried out.Finally,the optimal scheme was obtained.The results show that the sine distortion rate of air gap flux density wave and back-EMF wavereduce obviously and thetorque ripple was effectively suppressed after optimization design.