ANALYSIS AND IMPROVED DESIGN OF DIRECT-DRIVE CORELESS AFPM IN-WHEEL MACHINE FOR HEV APPLICATION

This paper illustrates the design of in-wheel direct-drive axial flux permanent magnet (AFPM) machine for hybrid electric vehicle (HEV) in order to obtain a wide speed range operation with high operation efficiency and low cogging torque. Using a coreless type of stators can help to improve the total machine efficiency as a result of power loss reduction. In order to achieve the direct drive without any mechanical transmission for HEVs, the wheel motor has been designed as a low-speed high-torque motor. Direct drive, in-wheel motors are ideal for vehicles, because of their high efficiency, compressed packaging, easy handling, and safety operation. The performance analysis of this axial flux permanent magnet in-wheel motor is done using finite-element method and the obtained results verify the validation of this proposed design method. The experimental results obtained from sample practical prototype, confirm the analytical method.