基于重复单元削弱永磁风力发电机齿槽转矩

摘要

Cogging torque is one of the important issues for permanent magnet （PM） wind power generator. To reduce the cogging torque, the expression of the cogging torque is studied based on the Fourier analysis. In this paper, a concept of repeat unit is proposed. It is found that the cogging torque is multiple of the cogging torque generated of a repeating unit, and a certain harmonic of cogging torque could be eliminated by relative shifting of repeat units with proper shifting angles. Based on the repeat unit, a method of PM shifting to reduce cogging torque of permanent magnet machine is presented. The new method to obtain the PM shifting angles is achieved. At last the method is verified by finite element method. The results show that the method to obtain the PM shifting angles is simple. With this method the cogging torque can be greatly reduced.%齿槽转矩是永磁同步风力发电机研究的重要内容之一。为了削弱永磁电机的齿槽转矩，运用傅里叶级数的方法分析了齿槽转矩的表达式，提出了一种重复单元的概念，发现电机的齿槽转矩为各重复单元产生齿槽转矩的同相叠加，将两个或几个重复单元相对偏移适当角度，可以消除它们产生的齿槽转矩中的某次谐波。由此提出了一种基于重复单元的偏移磁极削弱齿槽转矩的方法，给出了磁极偏移角度的确定公式，最后进行有限元仿真。结果表明，与现有方法相比，本文提出的磁极偏移角度计算方法简单，对电机齿槽转矩有显著的削弱效果，且不会引起新的低次谐波。