Improved Optimal Fault-Tolerant Control Considering Reluctance Torque for Five-Phase IPMSM in Aerospace Electric Actuation Application

For the output torque enhancement, an improved optimal torque fault-tolerant control considering reluctance torque is proposed for the five-phase fault-tolerant interior permanent magnet synchronous motor (FT-IPMSM) in the aerospace electric actuation area, which can solve the electromagnetic torque fluctuation issue due to the reluctance torque during fault-tolerant operation. The analytic expression for the electromagnetic torque of the FT-IPMSM is first proposed, which can accurately calculate the permanent magnet torque and reluctance torque. Then the improved optimal torque fault-tolerant control is proposed to guarantee the maximum torque per current (MTPC) performance, which can also reduce the electromagnetic torque fluctuation due to the reluctance torque of the FT-IPMSM in fault-tolerant operation condition. The quasi-proportional-resonant (QPR) control is adopted to track the time-varying phase current. Finally, the effectiveness of the proposed fault-tolerant control is verified by a 1.8 kW five-phase FT-IPMSM platform. The resulting FT-IPMSM system can guarantee the MTPC performance and significantly reduce the torque fluctuation caused by the reluctance torque during fault-tolerant operation, which has excellent fault-tolerant performance under the phase open-/short-circuit fault condition.