Fault-Tolerant Current Control of Six-Phase Permanent Magnet Motor With Multifrequency Quasi-Proportional-Resonant Control and Feedforward Compensation for Aerospace Drives

To improve the current tracking performance, this article proposes a new fault-tolerant current control for the six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) system with multifrequency quasi-proportional-resonant (QPR) control and back electromotive force (EMF) feedforward compensation, which can track the time-varying sinusoidal and nonsinusoidal reference currents in the stationary reference frame (SRF) under normal and fault conditions. First, the multifrequency QPR current controller with shunt topology is proposed to track the time-varying reference current in SRF, which can guarantee the current control performance regardless of the motor speed variation and the load torque change. Second, the optimized feedforward compensation method for the back EMF is proposed to further reduce the steady-state current tracking error, which takes the time delay of the digital implementation into consideration. Finally, the effectiveness of the proposed approach is verified on a 3 kW six-phase FTPMSM platform. The resulting six-phase FTPMSM system with the proposed current control has great current tracking performance, strong robustness to various external/internal disturbance, as well as low computational burden, which can guarantee the multiphase FTPMSM system performance in normal and fault conditions.