Fault-Tolerant Scheme for Single-Switch Open-Circuit Fault in CSI-Fed Five-Phase PMSM

Due to their inherent capability to provide short-circuit fault protection, combined with features, such as high torque density and reduced torque ripple, five-phase permanent magnet synchronous motors (PMSMs) driven by current-source inverters are highly suitable for mission-critical applications. However, unlike PMSMs, current-source inverters are more susceptible to faults. Conventional fault-tolerant techniques for mitigating open-circuit faults in current-source inverters typically assume that all the semiconductors in the affected inverter leg are faulty. In reality, the possibility of an open-circuit fault occurring in only one power switch has not been thoroughly studied. Consequently, this article introduces a fault-tolerant control (FTC) approach specifically designed to address single-switch open faults in five-phase PMSMs driven by current-source inverters. First, the paper evaluates the fault-tolerant capabilities under this particular fault condition. Then, two space vector pulse width modulation (SVPWM) strategies are developed and compared with existing SVPWM methods, focusing on winding copper losses and torque ripple. Finally, the effectiveness of the proposed FTC scheme is verified through experiments, demonstrating that this method can effectively reduce torque ripple and decrease winding copper losses.