Fault tolerant control of triple star-winding flux switching permanent magnet motor drive due to open phase

Abstract

The flux-switching permanent-magnet (PM) (FSPM) motor is a new class of stator-PM brushless machines, which offers the advantages of high reliability, high power density, and high efficiency. In this paper, a nine-phase FSPM motor with triple star-winding sets spatially displaced by 40 degrees fed by three pulse-width modulated voltage source inverters (VSIs) is proposed, and the fault tolerant operation of the proposed FSPM motor is addressed. The key of this paper is to investigate two remedial strategies for fault-tolerant operation of the FSPM motor drive under open-circuit fault. Firstly, by isolating the faulty star-winding set, the torque pulsations due to phase loss can be remedied, the so-called remedial BLAC operation mode. Secondly, by injecting fifth and seventh harmonic currents to reconstruct armature fields, the low-frequency torque pulsation can also be remedied, the so-called remedial BLAC with harmonic current injection operation mode. Finally, these two remedial operation modes are compared and verified by simulation and experimental results, hence confirming the validity of the proposed fault-tolerant FSPM motor drive.