Design of the Tri-redundant Permanent-Magnet Synchronous Machine for More-electric Aircraft

There is a strict demand on the reliability of the driving motor for the electrical actuator of the more electric aircraft. However, the power density is inevitably decreased if inceasing the reliability only by arranging multiple sets of windings to the stator. Given that, this paper provides a dual-stator tri-redundant permanent magnet fault-tolerant motor, which can output the rated power with single-redundancy winding faulty and 50% rated power with two-redundancy winding faulty, improving the reliability while maintaining the high power density. The selection of the winding topology was discussed comprehensively to choose that having lower coupling degree between different sets of three-phase windings. The structure of the rotor was optimized to reduce the rotor-eddy loss, and the strength of the rotor was evaluated as well. Then the thermal-analysis model was built and the thermal characteristics of the motor were calculated under different running conditions. Finally, a 6 kW, 12 000 rpm prototype was manufactured to verify the theoretical analysis.