Design and Comparison of Six-Phase Fault-Tolerant Interior Permanent Magnet Motor and Surface-Mounted Permanent Magnet Motor for Electric Vehicles

In this paper, we design and investigate the six-phase in-wheel fault-tolerant surface-mounted permanent magnet motor (SPM) and interior permanent synchronous motor (IPM) for electric vehicles (EVs) application. Firstly, the stator of the motor is designed based on the anti-short-circuit method and the main design parameters of both motors are listed. Then the electromagnetic performance and the motor loss of both motors are analyzed by finite-element analysis (FEA). In addition, the thermal analysis is conducted by utilizing Motor-CAD, which shows that both SPM and IPM encounter with magnet overheating problems. Therefore, the magnet segmentation basing on the skin depths calculation is adopted to reduce the eddy-current loss. Meanwhile, the thermal performance of both motors with non-segmented and segmented magnets under different working conditions are presented. Finally, the optimized model is achieved through the comparison between the two types of fault-tolerant permanent magnet synchronous motors (FTPMSM).