A Unified Open Switch Fault-Tolerant Control Method for Dual-Redundancy Permanent Magnet Synchronous Motor

Dual-redundancy permanent magnet synchronous motor (DR-PMSM) has been widely used in the aviation electrical actuation system, which shows excellent reliability for its redundancy structure. In aviation applications, it is crucial for the DR-PMSM to maintain stable torque and speed even during open-circuit faults (OCFs), thereby minimizing their impact. This article introduces a unified fault-tolerant control (UFTC) method that comes into effect automatically with no threshold and arbitration upon the occurrence of an OCF. The UFTC operates in a branch loop, ensuring that the dynamic performance of the DR-PMSM remains unaffected. It converts the OCF into a voltage residual and shifts fault-tolerant control (FTC) to residual compensation, eliminating the need for model reconstruction or current injection. The UFTC accommodates various OCF scenarios, including single-switch faults, multiswitch faults in a single inverter, and multiswitch faults in dual inverters. This method simplifies the FTC process for DR-PMSMs, eradicates diagnostic delays, and significantly reduces torque ripple and speed drops during fault conditions. The effectiveness of the UFTC is validated through experimental implementations.