The design and development of an axial flux permanent magnet brushless DC motor for wheel drive in a solar powered vehicle

This paper presents the development of a “weight-power trade-off” applicable to high-performance, power limited vehicles. The theory is then applied to the electric vehicle case to justify the pursuit of an “in the wheel” motor design. The singular benefits of axial flux geometry are discussed with reference to the particular requirements of electric motors for vehicular applications. The basic design process, construction, and test results for a motor fitted in a 26 inch wheel to drive a 260 kg all up weight vehicle are presented. At an output power of 1 kW, the attainable vehicle speed is 72 km/h, corresponding to a motor/wheel speed of 578 r/min and torque of 16.5 Nm, at an estimated motor efficiency of 94%