轴向磁场磁通切换永磁电机齿槽转矩分析

Analysis on cogging torque in axial field flux-switching permanent magnet machine

为了有效削弱轴向磁场磁通切换永磁电机的齿槽转矩,采用能量差分法,建立了该种电机齿槽转矩的解析表达式,针对表达式中的电机结构参数,利用全场域三维有限元法,分析了一台三相12/10极轴向磁场磁通切换永磁电机在不同结构参数下的齿槽转矩,得到当定子齿宽、定子槽口宽与永磁体磁化厚度均占内径圆弧7·5°,转子齿宽占内径圆弧10·5°,且为准扇形齿时,该电机的齿槽转矩最小;在定子轭部铁心不饱和的情况下,齿槽转矩随定子厚度减小而减小,而受转子厚度的影响较小。综合考虑电机不同结构参数对齿槽转矩和感应电势的影响,得到了削弱轴向磁场磁通切换永磁电机齿槽转矩的有效方法,有效地改善了该电机的运行性能。

The cogging torque in a novel 12/10 poles axial field flux-switching permanent magnet （AFF- SPM） machine was studied by combining analysis method and finite element method （FEM）. The analytical expression of cogging torque in the AFFSPM machine was built, the cogging torques for the different structure parameters were calculated on the basis of 3D whole field finite element method, and the change regularity between the cogging torque and the structure parameters was obtained. Namely, when the stator slot width, stator tooth width and the permanent magnet magnetization width are equal, and the rotor tooth is 1.4 times as wide as the stator tooth, the cogging torque in the AFFSPM machine is the least. In addition, the cogging torque is directly proportionate to the thickness of the stator, and less af- fected by the thickness of the rotor. At last, the effective methods for reducing the cogging torque in the AFFSPM machine were suggested after considering a balance between the cogging torque and the induced electromotive force （EMF）.