Study on FTO of Permanent Magnet Synchronous Motor for Electric Aircraft Steering Gear

As the core part of steering gear in electric aircraft, the failure of motor will threaten flight safety. Aiming at the fault problem of permanent magnet synchronous motor in the steering gear of electric aircraft, a fault-tolerant control (FTC) method based on three-phasefour-switch is proposed. The “Five-stage” SVPWM modulation method is designed to improve the problem of small flux freedom existing in the “Three-stage” SVPWM method, improve the degree of freedom and reduce the switching loss. Further combined with the sliding mode control idea, an improved sliding mode speed controller was designed to replace the traditional PI controller with fixed parameters. Thus, the improved sliding mode FTC strategy of electric aircraft permanent magnet synchronous motor based on “Five-stage” three-phasefour-switch was obtained to improve the robustness and rapidness of the system. The simulation results show that the proposed method can guarantee the stable operation of the steering gear and the flight safety of the electric aircraft even when the system inverter is faulty.