Design and Analysis of Double-Rotor Flux-Reversal PM Magnetic Differential Motor With Suppressed Rotor Coupling

This article proposed a novel axial-field double-rotor (AF-DR) flux-reversal permanent-magnet (FRPM) motor to provide reliable and safe steering action to electric vehicles with the magnetic differential (MagD) application. Unlike conventional mechanical and electronic differentials, the MagD can achieve desirable cornering without bulky parts and complicated control strategies. Moreover, compared with the existing AF-DR flux switching PM (FSPM) motor used in the MagD system that needs a reverse gear to decouple the two rotors, the AF-DR FRPM motor can directly provide differential action with suppressed rotor coupling. Thanks to the surface-mounted PM configuration of the AF-DR FRPM motor, the flux linked with the two rotors can be largely decoupled by the intact stator yoke, thus leaving the two rotors rotating at their own target speeds. The design, analysis, structural optimization, and motor performance evaluation of the presented AF-DR FRPM MagD motor using finite element analysis (FEA) are thoroughly provided in this article. Finally, a prototype of the proposed AF-DR FRPM motor is manufactured and tested to experimentally validate the analysis and simulation.