磁通切换型轴向磁场永磁电机定位力矩分析

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

为了有效削弱磁通切换型轴向磁场永磁(AFFSPM)电机的定位力矩,利用解析法与有限元法相结合,对AFFSPM电机的定位力矩进行分析.采用能量差分法建立了该类电机定位力矩的解析表达式;基于ANSYS建立了一台三相12/10极AFFSPM电机全场域三维有限元模型,对其定位力矩进行仿真计算.结果表明:当转子齿宽占内径圆弧10.5,°且为准扇形齿时,该电机的定位力矩最小;在定子轭部铁心不饱和的情况下,定位力矩随定子厚度减小而减小,而受转子厚度的影响较小;转子齿表面开合适的辅助凹槽有利于削弱该电机的定位力矩;两侧定子错齿虽然可以削弱定位力矩,但会给电机运行带来副作用.

An axial field flux-switching permanent magnet（AFFSPM） machine was presented as a wind power generator.To effectively reduce the cogging torque in the AFFSPM machine,a study by combining analysis method and finite element（FE） method was conducted.The analytical expression of cogging torque in AFFSPM machines was given,a whole field 3-D FE analysis model of 3-phase 12/10-pole AFFSPM machine was built based on ANSYS software,and the cogging torque was simulated by FE method.The results indicate that when the rotor tooth width is 1.4 times the stator tooth width,the cogging torque in the AFFSPM machine is the least.The cogging torque is directly proportionate to the thickness of the stator,and less affected by the thickness of the rotor.Grooving appropriate dummy slots on the rotor teeth surfaces can reduce the cogging torque.Although staggering stator teeth can also reduce the cogging torque,it is detrimental to operation of the AFFSPM machine.