A New Fault-Tolerant Permanent-Magnet Machine for Electric Vehicle Applications

Abstract

This paper proposes a new fault-tolerant permanent-magnet (PM) brushless machine for four-wheel independently driven electric vehicles (EVs). The key of the proposed machine is to make tooth widths unequal of inner stator, hence, offering more trapezoidal back-EMF waveform. Due to the fact that the radial PMs are embedded in the outer rotor, the proposed machine incorporates the merits of high torque-to-weight ratio, mechanical robustness, and high air-gap flux density. In addition, multiphase and single-layer fractional slot concentrated windings are employed to improve the reliability. The electromagnetic characteristics of the proposed machine are analyzed by using the time-stepping finite-element method (FEM) and field-circuit cosimulation method, such as magnetic field distribution, flux destiny, flux linkage, and torque, verifying the effectiveness of the theoretical analysis.