Design and application of axial-flux permanent magnet wheel motors for an electric vehicle

This paper introduces an optimal design of an axial-flux permanent magnet wheel motor for a small electric vehicle. This vehicle is driven directly by two wheel motors installed on its rear wheels, which are compact, low weight, and highly efficient. The optimal current waveform of the same pattern as the back electromagnetic force is used to increase the output torque and efficiency, while the field weakening control is used to extend the speed range of the motor. The electric differential system is proposed for stable maneuverability of the vehicle against system uncertainties and external disturbances.