New dual-airgap axial and radial-flux induction motor for on wheel drive electric propulsion systems

This paper deals with the design of a wheel-directly coupled induction motor which has a dual air-gap, axial and radial-flux configuration for a small prototype of an experimental electric propulsion system. This type of motor has a single stator and a two squirrel cages mounted on the same rotor; the former as a radial cage and the second as an axial cage in a discoid topology. First, the design considerations of electric propulsion systems and the basic layout of the proposed drive system are presented. Then, machine design considerations and structure are described. After this, magnetic and electric equivalent circuits of such a configuration are derived and FEA is used to analyze the machine structure for saturation. Finally, sizing and characteristics of the implemented motor prototype are discussed and compared with a single air-gap axial flux induction motor