基于定子齿齿肩削角的内置永磁电机齿槽转矩削弱方法[JP]

为削弱电动汽车用内置式永磁同步电机的齿槽转矩，提出了一种定子齿齿肩削角的方法。建立定子齿齿肩削角前后的气隙长度等效模型，推导有效气隙长度分布函数，分析定子齿齿肩削角降低气隙磁密低次谐波幅值，削弱齿槽转矩的机理；以三相8极36槽内置式永磁同步电机为例，利用有限元法对定子齿齿肩削角的不同形状和尺寸进行仿真分析，获得最优参数匹配。结果表明，定子齿齿肩椭圆形削角有效降低了气隙磁密谐波幅值，提高了电机反电势波形正弦性，削弱了齿槽转矩；优化后的电机齿槽转矩的峰值降低了77.2%，反电动势的9，13，15，17，19和21次谐波幅值明显下降，电机的输出品质显著提高。所提方法通过改变气隙长度分布函数，减小了气隙磁密特定谐波，可有效削弱永磁电机的齿槽转矩，为同类型电机齿槽转矩的优化提供参考。

Cogging torque reduction method of internal permanent magnet motor based on stator tooth shoulder chamfer

In order to reduce the cogging torque of interior permanent magnet synchronous motor (IPMSM) for electric vehicles,a method of stator tooth shoulder chamfer was proposed.The equivalent model of air gap length before and after the chamfer of stator tooth shoulder was established,and the effective air gap length distribution function was deduced,so as to analyze the mechanism of stator tooth shoulder chamfer reducing the low harmonic amplitude of air gap magnetic density and weakening the cogging torque.To explore the optimal shapes and sizes of the chamfer based on a IPMSM with three phase 36-stator-slot/8-rotor-pole topology,the finite element method was purposely utilized for conducting optimization.The comparative analysis results show that the elliptic chamfer of stator tooth shoulder can effectively reduce the amplitude of air gap magnetic dense harmonic wave,improve the sinusoidal waveform of motor back electromotive force (EMF) and weaken the cogging torque.The peak value of the cogging torque of the optimized motor is reduced by BF]77.2%BFQ],the amplitude of the 9th,13th,15th,17th,19th and 21th harmonics of the back EMF are significantly reduced,and the output quality of the motor is significantly improved.The provided method reduces the specific harmonic of air gap magnetic density and weakens the cogging torque of permanent magnet motor by changing the air gap length distribution function,which provides some theory and experience for the optimization of cogging torque of the same type of motor.