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 are preferred for safety critical areas, including aerospace and military industries, owing to superior torque density and robust fault tolerance. Despite the advantages, multi-phase machines are not immune to faults, particularly for the inverters due to potential power switches failures. However, in such systems, there has been no research on single-phase and non-adjacent two-phase open-circuit faults of current-source inverters when the non-zero faulty phase winding current is considered. Therefore, this paper analyses and develops a fault-tolerant control strategy with faulty phase winding current compensation to manage the faults. Firstly, 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 pulse width modulation methods are introduced for each fault case. Finally, the effectiveness of the control strategy is validated by experimental results. Under single-phase and non-adjacent two-phase open-circuit faults 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.