FSPM machines with twisted-rotor structure

High torque density, wide speed range are required in electric motors used in electric vehicles. Based on the comparison of flux-weakening capability of alternate and all poles wound machines, this paper employs twisted-rotor structure and chooses the optimal twist angle to improve the symmetry of flux-linkage of alternate poles wound FSPM machine without flux-linkage magnitude reduction and reduce the cogging torque effectively with negligible average torque reduction. This study brings the motor with the advantages of strong flux-weakening capability and good torque performance.