基于电流谐波注入的磁通切换永磁电机定位力矩补偿方法

Cogging Torque Compensation for Flux-switching Permanent Magnet Motor Based on Current Harmonics Injection

磁通切换永磁电机具有功率密度高、输出转矩大、反电动势正弦等优点,而较高的气隙磁密与定转子双凸极结构会产生较大的定位力矩。定位力矩会引起电机运行时的转矩脉动、振动和噪声问题,从而限制了磁通切换永磁电机的应用。从控制角度出发,提出一种新型的采用电流谐波注入法补偿定位力矩的控制策略,即通过注入谐波电流产生的转矩抵消定位力矩中的基波与二次谐波分量,从而达到补偿的目的。通过半实物仿真平台dSPACE实现了该控制算法,并在一台2kW磁通切换永磁电机的驱动系统上验证了所提出补偿控制方法的有效性。该控制方法也可拓展应用到其它反电动势为正弦且定位力矩较大的永磁电机驱动系统。

The flux-switching permanent magnet （FSPM） machine has the advantages of high power density, large torque capability and essentially sinusoidal back-EMF. However, due to the high airgap flux density produced by magnets and the doubly-salient structure, the resultant cogging torque is relatively large, which may cause unfavourable torque ripple, noise and vibration and consequently compromises its application. A new method is proposed in which harmonic current is added into the reference current to produce an additional torque component which is used to compensate the fundamental and 2nd order harmonic components of cogging torque. Experimental evaluations of the proposed scheme are carried out on a dSPACE-controlled 2 kW FSPM motor drive platform. Test results obtained demonstrate the effectiveness of the proposed method in compensating cogging torque. It should be emphasized that this method can be applicable to all permanent magnet machines having sinusoidal back-EMF and relatively higher cogging torque.