Investigation of a novel five-phase modular permanent-magnet in-wheel motor

To increase the driving comfortableness and reliability of electric vehicles, multi-phase fault-tolerant permanent-magnet synchronous motors (PMSM) are becoming promising candidates, especially for the vehicles adopting in-wheel PMSM schemes. In this paper, a novel five-phase fault-tolerant modular in-wheel PMSM is proposed and investigated. The applicable slot/pole combinations are recommended for five-phase PMSM, and the 40-slot/42-pole scheme is selected for the wheel driven application in this paper. The electromagnetic structure was designed, and the fault-tolerant tooth was optimized to obtain better torque curve. The fault-tolerant ability was analyzed under some fault conditions, including one phase open-circuited, two adjacent phases open-circuited, two non-adjacent phases open-circuited and one single phase short-circuited. The results indicate that the drive system can survive these fault conditions; through proper current control strategies, different fault-tolerant performances can be obtained. The proposed scheme is proved to have satisfying electromagnetic and fault-tolerant performances.