Optimal Design and Control of a Wheel Motor for Electric Passenger Cars

An optimal design and control technology of a wheel motor for electric passenger cars is proposed. The objectives are to maximize the driving torque, efficiency, rated speed, and to minimize weight of the motor under various constraints of size, materials, and power sources. A sandwich-type of disc motor is then obtained with a rotor embedded with NdFeB magnets and two plates of stators. The optimal driving current waveform is proved to be the same as that of the back electromotive force. This dedicated wheel motor is applicable to pure or hybrid electric vehicles as a promising solution to the direct-driven electric vehicle.