永磁无刷直流电动机低脉动转矩研究

针对永磁无刷直流电动机在运行过程中存在明显脉动转矩的问题，研究了一种新结构低脉动转矩永磁无刷直流电动机。首先对普通永磁无刷直流电动机在电流换相、极弧系数小于1和电枢反应等3种因素下的脉动转矩进行了物理解析；然后以脉动转矩的变化规律为切入点，提出一种通过电机本体产生2个幅值相同、频率相同、相位互差180°电角度的脉动转矩，实现脉动转矩峰谷互补的抑制策略，并通过理论分析找到了脉动转矩峰谷互补的实现方法；最后研制了低脉动永磁无刷直流电动机及控制器，通过实验验证了脉动转矩抑制的有效性，与普通永磁无刷直流电动机相比，实验结果表明可以减少约70%的脉动转矩。

Research on Permanent Magnet Brush-less DC Motor with Low Pulsating Torque

The permanent magnet brush-less DC motor (BLDCM) has obvious pulsating torque during operation, a new low pulsating torque BLDCM is proposed in order to solve this problem. Firstly, the physical analysis of permanent magnet brush-less DC motor pulsating torque is obtained under three factors, which are current commutation, polar arc coefficient less than 1 and armature reaction. Then, a new motor can generate the pulsating torque have same amplitude, same frequency and 180° phase difference is proposed, in order to realize the suppression strategy of the peak and valley complementation of the pulsating torque, and the method of peak and valley complementation of pulsating torque is found through theoretical analysis. Finally, the low ripple permanent magnet brush-less DC motor and its controller are developed, the effectiveness of pulsating torque suppression is verified through experiments. Compared with ordinary brush-less DC motor, the experimental results show that the pulsating torque can be reduced about 70%.