Abstract
Cogging torque in permanent-magnet brushless DC (BLDC) motor causes torque and speed ripples, as well as acoustic noise and vibration, especially in low speed and direct drive applications. In this paper, the stator core shape is optimized by using a level set based topology optimization to reduce cogging torque. The level set method can represent the precise boundary shape of structure and also deal with complex topology changes during the optimization process. Different from the conventional rectangular meshes, the level set technique based triangular finite element meshes are presented in this paper to deal with irregular domains. The comparison of cogging torque calculated before and after topology optimization verifies the advantages of the level set topology optimization based on triangular meshes.