Finite element analysis of cogging torque in low speed permanent magnets wind generators

Abstract

This paper deals with the finite element estimation of cogging torque oscillations that occur in multi-pole permanent magnets synchronous wind generators. The numerical analysis is carried out using a 2D plane-parallel finite element model of the machine and afterward a more elaborated 3D model able to take into account the skewing of the stator slots. The numerical results are discussed and compared with the experimental measurements. This paper presents also the influence of the magnetization characteristics of stator and rotor cores as well as the influence of the magnetization orientation of the permanent magnets of the generator on the cogging torque values.