Design of multi‐phase permanent magnet synchronous motor with fractional‐slot windings for electromagnetic vibration reduction considering stator teeth modulation

Abstract A multi‐phase permanent magnet synchronous motor (PMSM) with fractional‐slot windings is proposed to reduce electromagnetic vibration and improve torque performance. Firstly, the analytical expression of electromagnetic force is derived, and the stator teeth modulation effect of electromagnetic force is introduced. The spatial order of the electromagnetic force and the stator teeth modulation are closely related to the slot‐pole combination of the PMSM. Then, three PMSMs with different slot‐pole combinations are presented, and they represent fractional‐slot concentrated winding, integral‐slot distributed winding and fractional‐slot distributed winding, respectively. Their torque performance and electromagnetic vibration performance are studied and compared considering stator teeth modulation. In addition, the multi‐phase winding technology is adopted to further improve the torque performance of the proposed PMSM. Finally, a 90s20p PMSM is manufactured, and the finite element method and experimental method are used to verify the proposed low vibration design method.