Torque ripple minimization of a five-phase permanent magnet assisted synchronous reluctance motor under open phase faults

This paper aims to present an analysis of the torque ripple minimization technique for a five-phase permanent magnet assisted synchronous reluctance motor (PMa-SynRM) at different types of open phase faults. Minimizing the torque ripple has been the best practice to reduce the motor vibration. Especially, in a five-phase PMa-SynRM the vibration becomes substantially high at the time of open phase faults. This paper investigates three different open phase faults that occur in a five-phase PMa-SynRM. Due to these faults, the presence of the harmonic contents in the phase currents are calculated which eventually produces ripple in the d-q axis current signature. In this paper, a method of harmonic cancellation is proposed which improves the torque ripple and reduces the motor vibration. Extensive theoretical analysis has been carried out through finite element analysis (FEA) to present different fault scenarios. The experimental tests are conducted for the five-phase machine by utilizing 3.7 kW dynamo which has been controlled with TI DSP (F28335) and five-phase inverter system.