Fault-Tolerant Control Method of Current-Source Inverter-Fed Five-Phase PMSM Under Winding Open-Circuit Faults

Five-phase permanent magnet synchronous motors (PMSMs) driven by current-source inverters (CSIs) are receiving increasing attention in safety–critical applications such as aerospace and automotive systems, due to high torque/power density and excellent fault tolerance. Despite these merits, their vulnerability to faults such as winding open-circuit remains a critical concern. However, limited research has been conducted on single or two-phase (adjacent and nonadjacent) winding open-circuit faults (OCFs) and the resulting neutral-point voltage (NOV) oscillations. To address this issue, this article analyzes various winding fault scenarios and reveals the phenomenon and characteristics of NOV oscillations. Based on the analyses, a novel fault-tolerant control (FTC) strategy with NOV oscillations compensation is proposed. First, the NOV model under fault conditions is established, from which the winding current model and related fault-tolerant current expressions are derived. Then, a reduced-order decoupled model is developed. Subsequently, novel space vector pulsewidth modulation strategies are proposed for various winding fault scenarios. Finally, experimental results validate the proposed strategy. Compared with conventional methods, the FTC without NOV compensation reduces the torque ripple by 85.6% and 77.2% under adjacent and nonadjacent two-phase faults, respectively. With the compensation method, additional torque ripple reductions of 38.8% and 7.7% are achieved.