Design and Simulation Analysis of a Novel Outer Rotor IPM Motor Used in Electric Vehicles

Aiming at the distributed drive system of electric vehicles, this paper presents an outer-rotor permanent-magnet synchronous in-wheel motor with a novel U-shape rotor structure. Instead of the traditional surface-mounted permanent-magnet structure, adopting the U-shape interior permanent magnet (IPM) structure is beneficial to improving the performance of the in-wheel motor of electric vehicles (EVs). The finite element analysis (FEA) models of the U-shape interior permanent magnet motor and the surface-mounted permanent-magnet motor are both established to compare. The results show that the novel U-shape interior permanent-magnet motor not only reduces the amount of permanent magnet, but also improves the back electromotive force (EMF), torque output, flux weakening capability and reduces the cogging torque. The research shows that the U-shape interior permanent magnet motor is better suited to the requirements of the motor used in electric vehicles, and provides some reference for the design of the in-wheel motor of electric vehicles.