Inter-tum Short-circuit Fault Diagnosis of Six-Phase FTPMSM System Based on PWM Harmonic Current Extraction

Abstract

A novel on-line fault diagnosis method based on high frequency (HF) harmonic current for inter-turn short circuit fault (ITSCF) of six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) is proposed in this paper, which can detect and locate the fault phase even in fault toleration condition. The fault model of ITSCF with H-bridge inverter is first revealed for the FTPMSM, and the feature of harmonic current generated by pulse width modulation (PWM) under both normal and post-fault condition. The periodic root mean square (PRMS) of HF harmonic current based fault diagnosis method is then proposed with band-pass filter to extract the HF harmonic current component. The resulting fault diagnosis approach has simple structure, low computation burden, fast detection performance, which can detect the ITSCF online for FTPMSM system under both normal and fault tolerant operation conditions. Finally, the effectiveness of the proposed fault diagnosis method is verified by simulation.