表贴式永磁同步电机磁极不对称化齿槽转矩削弱方法

Cogging Torque Reducing Method Based on Asymmetric Pole Design of Permanent Magnet Synchronous Motors

表贴式永磁同步电机的齿槽转矩可导致转矩脉动,引发振动与噪声的问题,为削弱永磁同步电机的齿槽转矩,提出一种通过磁极极弧宽度不对称化设计实现齿槽转矩削弱的方法。首先对不对称磁极表贴式永磁同步电机的气隙磁密波形进行了计算和仿真,进而分析了不对称磁极对齿槽转矩的影响规律和削弱原理,推导出使齿槽转矩最小化的磁极不对称率表达式。通过有限元仿真对最优设计及齿槽转矩进行了验证,仿真结果表明,最优磁极不对称率计算值与仿真值误差为3.1%,所提出的不对称磁极方法使齿槽转矩减小了91.3%。

The cogging torque of surface mounted permanent magnet synchronous motor(PMSM)can cause torque ripple,which can lead to vibration and noise problems.In order to reduce the cogging torque of PMSM,a method of reducing cogging torque by asymmetric design of pole arc width is proposed in this paper.Firstly,the air gap flux density wave form of asymmetric pole surface mounted PMSM is calculated,then the influence law and weakening principle of asymmetric magnetic pole on cogging torque are analyzed,and the calculation equation of optimal pole asymmetry ratio to minimize cogging torque is derived.The optimal design and cogging torque are verified by finite element(FE)simulation.The FE simulation results show that the error between the calculated value of the optimal pole asymmetry ratio and the simulation value is 3.1%,and the cogging torque is reduced 91.3%by using this optimization method.