Optimal Design of Yokeless and Segmented Armature Axial Flux Permanent Magnet Machine Based on Quasi-Three-Dimensional Model

This paper presents the optimal design of a dual three-phase yokeless and segmented armature (YASA) motor for electric aircraft propulsion. A multi-layer quasi-threedimensional (quasi-3-D) equivalent model is established, with the calculation accuracy being verified. Based on parametric sensitivity analysis, the key design parameters of the YASA motor are identified. The purpose of the motor design is to increase the torque capability and reliability, while restricting the weight of the motor, thereby making it more suitable for aircraft propulsion. The multi-objective optimization is implemented, aiming to maximize the torque density and minimize the torque ripple, with the constraint of the average torque above 70 Nm. The results show that the torque density of the optimized machine is increased by 19.7% in comparison with the baseline design, due to better utilization of the slot area.