Open-Phase Fault-Tolerant Control Approach for EV PMSM based on Four-Leg VSI

Abstract

The major malfunction of Permanent Magnet Synchronous Motor (PMSM) in Electric Vehicle (EV) applications is an open-phase defect, which degrades motor efficiency and increases losses due to unbalanced phase currents. Traditional Fault-Tolerant Control (FTC) techniques, on the other hand, could suffer from the monitoring problems of sinusoidal-shaped current references. In this study, a proposed fault-tolerant approach for open-phase during the driving cycle and starting of the PMSM is suggested, which differs from earlier fault-tolerant techniques by suggesting a proposed compensating transformation matrix for current and voltage references in the d-q rotating reference frame will be translated to the phase current and voltage references of the two healthy remaining phases. The proposed setup enables the EV to be operated under open-phase fault-tolerant (OPFT) with simple controller and high performance. Furthermore, since the proposed system depends on a four-leg inverter, it has a higher fault-tolerance capability than the three-phase Voltage Source Inverter (VSI) technique, to also compensate the possibility of loss of any VSI leg, but for sure with additional cost of the overall drive system. Eventually, the simulation output results supported the suggested fault-tolerant approach under Field-Oriented Control (FOC) for different modes of operations.