PWM Harmonic-Current-Based Interturn Short-Circuit Fault Diagnosis for the Aerospace FTPMSM System Even in the Fault-Tolerant Operation Condition

This article proposes a new pulsewidth modulation (PWM) harmonic-current-based diagnostic method for the interturn short-circuit fault (ITSCF) of fault-tolerant permanent-magnet synchronous motor (FTPMSM) drives, which is able to detect and locate the fault phase for the system even in the fault-tolerant operation (FTO) condition. The ITSCF model for the H-bridge drive-based FTPMSM system is first proposed, while the high-frequency harmonic current component and impedance are analyzed both in normal and ITSCF conditions. The PWM harmonic-current-based fault diagnostic approach is then proposed to confirm the fault phase, which consists of the bandpass filter, the periodic root-mean-square calculator and the fault identification. The resulting fault diagnostic method has a simple structure, fast fault detection, good robustness, and low computational burden, which can achieve the ITSCF for the FTPMSM system both under normal and FTO conditions. The effectiveness of the ITSCF diagnostic method is verified via the six-phase FTPMSM experimental platform, which can provide a guideline for the ITSCF mitigation and FTO of the FTPMSM system.