Comparison of outer-rotor permanent magnet machines for in-wheel drives

This paper quantitatively discuss and compare the emerging outer-rotor PM in-wheel motor drives, which can directly couple with the EV tire rim and remove the traditional mechanical transmission. These new types of in-wheel motor drives include the PM hybrid brushless (PMHB) type, PM memory brushless (PMMB) type, PM magnetic-geared (PMMG) type, and PM vernier brushless (PMVB) type. And all of them are able to produce the high torque output by their distinct features of flux control or flux modulation. Their configurations, in-wheel drive operation principles, and detailed operation performances are given to verify the validity of their in-wheel applications.