Optimal pole shape design for the reduction of cogging torque of brushless DC motor using evolution strategy

This paper describes a design procedure that reduces the cogging torque of brushless DC motors. This paper proposes that a predefined slot shape on the pole surface reduces the cogging torque. Standard finite elements are used for field calculation, Maxwell stress tensor for torque calculation and an evolution strategy for the optimal design process to determine the slot size. Verified experiment shows that the proposed algorithm reduces the level of mechanical vibration and noise substantially.