Cogging torque investigation in permanent magnet synchronous motor used for electrical vehicles

The present paper presents an analysis regarding the influence of the form and arrangement of permanent magnets on the value of the cogging torque for a surface permanent magnet synchronous motor, designed for the direct drive of the wheels of a vehicle. There are taken into consideration influences caused by: the constructive form of the magnets, the ratio between the pole-arc and the pole-pitch, the opening of the stator slots, the introduction of additional slots on the stator teeth, the asymmetrical distribution of the permanent magnets. The study takes into consideration 2D models developed on the basis of the validated 2D model for the built machine. The authors present a few general conclusions valid for the construction type of the analyzed machine.