考虑加工误差的表贴式永磁伺服电机齿槽转矩分析与抑制

Analysis and Suppression of Cogging Torque in Surface-mounted Permanent Magnet Servo Machines Considering Manufacturing Tolerances

在永磁伺服电机中,齿槽转矩对加工误差非常敏感。为获取实际加工误差对齿槽转矩变化规律的影响,本文首先采用能量法建立考虑加工误差的齿槽转矩解析表达式,并分析了齿槽转矩对各种加工误差的敏感性。其次,基于蒙特卡罗方法,通过实测与供应商提供的数据估计各误差的概率分布,由概率分布产生随机样本,据此建立考虑加工误差的有限元模型,计算各模型的齿槽转矩,由此获得齿槽转矩及其频谱的分布规律。并且,论证了定子冲片循环旋转方法的最优旋转槽数,基本消除了定子侧误差产生的额外齿槽转矩。最后,从生产的一批电机中随机抽取样本进行齿槽转矩测试,验证了本文所用分析与抑制方法的可行性。

The manufacturing tolerances have a great influence on cogging torque in permanent magnet servo machines.In order to obtain the distribution regular pattern of cogging torque considering manufacturing tolerances in mass production,this paper used energy method to derive the analytical expression of the cogging torque.The sensitivity of cogging torque to various manufacturing tolerances was also analyzed.Then based on the Monte Carlo method,the probability distribution of each error was estimated by the data provided by the measurement or the supplier,and then samples were randomly generated from the probability distribution.The finite element model considering the manufacturing tolerances were established and the cogging torque of each model was calculated.The distribution law of cogging torque and its spectrum was obtained.Furthermore,the optimal number of rotation slots in the stator lamination cycle rotation method was demonstrated,and the additional cogging torque generated by stator side error was basically eliminated.Finally,taking out one from a number of finished motors,and the cogging torque test was carried out,which was in agreement with the calculated results of this paper.