磁极偏移削弱永磁电机齿槽转矩方法

研究了永磁电机磁极偏移对齿槽转矩的影响,发现当每极槽数不为整数时,磁极偏移会引入新的齿槽转矩谐波.因此要通过磁极偏移减小齿槽转矩,除了减小永磁体对称时存在的齿槽转矩谐波外,还要减小新引入的低次谐波.为解决现有的永磁体偏移角度计算方法存在的不足,本文推导了磁极偏移时齿槽转矩的表达式,提出了确定永磁体偏转角度的新方法.有限元计算结果表明:与现有的方法相比,本文提出的磁极偏移角度计算方法得到的偏转角度对原有齿槽转矩谐波以及新引入的低次谐波都有较好的削弱作用,因此能较好地减小齿槽转矩.

Cogging Torque Reduction Method of Magnet Shifting in Permanent Magnet Motors

The method of permanent magnet(PM) shifting to reduce cogging torque of PM motor was studied. It is found that if the slot number per pole is not an integer, new lower harmonics of cogging torque may be introduced when PM shifting is adopt. In order to reduce cogging torque by PM shifting, both the original harmonics and new lower harmonics of cogging torque should be reduced. The analytical expression of the harmonics of cogging torque with PM shifting was studied, and based on the analytical expression of cogging torque, the new method to obtain the PM shifting angles was achieved. At last the method is verified by finite element method.