Fault tolerant permanent magnet motor drives for electric vehicles

Abstract

This paper presents a novel five-phase fault tolerant interior permanent magnet (IPM) motor drive with higher performance and reliability for electric vehicles applications. A new machine design along with efficient control strategy is developed for fault tolerant operation of electric drive without severely compromising the drive performance. Fault tolerance is achieved by employing a five phase fractional-slot concentrated windings configuration IPM motor drive, with each phase electrically, magnetically, thermally and physically independent of all the others. The proposed electric drive system presents higher torque density, negligible cogging torque, and about ±0.5% torque ripple. Power converter requirements are discussed and control strategies to minimize the impact of machine or converter fault are developed. Besides, all the requirement of a fault tolerant operation, including high phase inductance and negligible mutual coupling between phases are met. Analytical and finite element analysis and comparison case studies are presented.