Stator Configuration for Cogging Torque Minimization of Surface Mounted Permanent Magnet Synchronous Generators

Abstract

In this study, we present the structural changes in the stator core to reduce the cogging torque in a surface-mounted permanent magnet synchronous generators. The effect of these structural changes on cogging torque and generator performance has been investigated, 2D-3D finite element analysis (FEA) and analytical results have been given comparatively. The magnetic equivalent circuit and the relative permeability models have been used to obtain the airgap flux density required for the calculation of cogging torque. Airgap and magnetic field in the magnet area have been firstly calculated as slotless effect and then re-expressed taking into account a relative permeability function (correction factor) obtained by appropriately adding slots. A 4- kW, 24-pole, 72-slot radial-flux machine has been designed and optimized to implement the proposed structural change and analytical method.