Electromagnetic design and optimization of permanent Magnet synchronous motor for electric aircraft

Abstract

This paper designs a 12 kW, 6000 r/min outer-rotor permanent magnet synchronous motor for electric aircraft propulsion. The motor adopts 44-pole 42-slot fractional-slot concentrated winding, N45UH permanent magnets and DW310-35 silicon steel. Axial segmented skewed pole technology is used to reduce torque ripple. Simulation results show that 5-segment skewed pole reduces peak cogging torque from 0.105 N·m to 0.0036 N·m, and load torque ripple from 5.82% to 1.96%, with only 0.3% average torque loss. The rated efficiency reaches 93.53%, power density 3.74 kW/kg, and no-load back EMF THD 4.7%. Thermal verification under forced air cooling (25 m/s) shows that the maximum winding temperature is 152.0 °C and the permanent magnet temperature is 108.2 °C, both within material limits, confirming safe operation. The design meets high power density and low vibration requirements for aircraft propulsion.