A Fault-Tolerant Control Strategy Using Faulty Phase Current Compensation for Five-Phase PMSM Fed by Current-Source Inverters Under Inverter Open-Circuit Faults

Five-phase permanent magnet machines with current-source inverters (CSIs) are preferred for safety-critical areas, including aerospace and military industries, owing to superior torque density and robust fault tolerance. Despite the advantages, multiphase machines are not immune to faults, particularly for the inverters, due to potential power switch failures. However, in such systems, there has been no research on single-phase and nonadjacent two-phase open-circuit faults (OCFs) of CSIs when the nonzero faulty phase winding current is considered. Therefore, this article analyses and develops a fault-tolerant control (FTC) strategy with faulty phase winding current compensation to manage the faults. First, the faulty phase winding current model is established, and the fault-tolerant currents are subsequently derived. Then, a reduced-order decoupled mathematical machine model is proposed, and space current vector pulsewidth modulation methods are introduced for each fault case. Finally, the effectiveness of the control strategy is validated by experimental results. Under single-phase and nonadjacent two-phase OCFs of the inverter, the fault-tolerant strategy with faulty phase winding current compensation can reduce the torque ripple by 14.98% and 23.21%, respectively, compared with not adopting it.