Evolution and comparison of three typical permanent magnet machines for all-electric aircraft propulsion.

In this paper, three typical permanent magnet machines for All-Electric aircraft propulsion are designed, optimized and compared. Firstly, the necessary performances are determined based on the requirements of high power/torque density and an aircraft with a maximum takeoff weight of 1500 kg. The initial structures of interior permanent magnet (IPM) synchronous machine, vernier permanent magnet (VPM) machine and flux-switching permanent magnet (FSPM) machine are designed with identical stator outer radius and rotor shaft length. Then, parametric sensitivity analysis and multi-objective particle swarm are combined as an optimization methodology to optimize these machines. Based on the finite element analysis, the electromagnetic performances such as no-load airgap flux density harmonic spectrum, cogging torque, average output torque, losses, efficiency and power factor, etc., are generally compared and analyzed. Subsequently, the discussions are carried out, where the strength and weakness of these three machines are concluded and the future prospects are suggested. Finally, it is concluded that if effective measures are implemented to reduce the permanent magnet eddy current loss and improve the power factor, the VPM machine would be the most suitable choice among these machines for All-Electric aircraft propulsion. [ABSTRACT FROM AUTHOR]