常规双凸极永磁(doubly salient permanent magnet，DSPM)电机通常采用集中绕组设计，且定子上每个永磁体对应整数倍的相绕组，造成了各相磁路每相最大与最小磁链处的变化率不一样，由此导致了各相反电势的偏差及每相反电势的左右不对称。每相绕组的各个串联线圈的自感随转子位置呈同方向变化，加剧了每相自感的波动程度，从而导致了磁阻转矩及转矩脉动的增加。提出一种新的DSPM电机及其设计方法——换位设计，以保持各相磁路严格对称，并且每相邻线圈的自感随转子位置变化趋势正好相反，从而可以最大程度地削弱磁阻转矩及电磁转矩脉动。利用时步有限元法进行计算，并与一台现有的类似结构的DSPM电机进行比较，样机的实验结果验证了该方法的有效性。

The conventional doubly salient permanent magnet (DSPM) motor usually adopts the concentrated winding connection and each permanent magnet (PM) in the stator is corresponding to the times of an integral number of the phase winding. This conventional configuration inevitably causes the asymmetry of the magnetic circuits among phases and the different variation between the maximum and minimum flux linkages. Consequently, it leads to the minor difference of the electromotive force (EMF) waveforms among phases and the asymmetric contour of the phase EMF waveform. Moreover, the coil inductance varies with the rotor position in the same direction, which further increases the fluctuation of the phase inductance, hence leading to the increment of the reluctance torque and the corresponding torque ripple. The purpose of this paper was to present a new DSPM motor and the corresponding new design approach. Based on the proposed position switching design idea, the magnetic circuits of the phases can keep strict symmetrical. Also, the variation of each adjacent coil inductance versus the rotor position possesses the contrary direction. Hence, the reluctant torque and the corresponding torque ripple can be significantly suppressed. By using the time-stepping finite element method, the characteristics of the proposed DSPM motor were obtained. Also, a quantitative comparison of the proposed DSPM motor and the conventional DSPM type was given. The prototype was built and the validity of this new design approach was verified by experimental results.

国家863高技术基金项目(2007AA05Z233)；上海市自然科学基金项目(09ZR1411500)。