Control Strategy for a Five-Leg Inverter Supplying Dual Three-Phase PMSM

This study presents a novel control strategy for a five-leg inverter-fed dual three-phase permanent-magnet synchronous motor (DT-PMSM)system. Three different five-leg inverter topologies (operating modes) can be reconfigured by choosing a pair of phases for sharing the common leg. The five-leg inverter operation mode with 150° phase difference can achieve full torque output, but the utilization of DC bus voltage is low. The operation mode with 30° phase difference has higher DC bus voltage utilization but lower output torque. The modified double zero-sequence injection (DZI) PWM strategy based on carrier-based PWM (CBPWM) for five-leg inverter operating modes is proposed. This strategy can achieve the maximum DC bus voltage utilization. The five-leg inverter operating modes can be used as a fault-tolerant solution for the occurrence of a fault in one leg of the six-leg inverter. Compared with the commonly used open phases fault-tolerant control (FTC) strategies, this strategy has the advantages of without increasing the stator copper, reducing the torque ripples, and implementing easily. Experimental results verify the effectiveness and feasibility of the proposed strategy.