Design and Scaling Effects of Permanent Magnet Synchronous Machines for Propeller Direct Drives

Surface permanent magnet synchronous machines (SPMSM) are generally viewed as the most promising electrical machine type for aircraft propulsion. Simultaneously, the power range per propulsion unit is becoming more flexible through distributed propulsion options. Therefore, the scalability effects of SPMSM for propeller drives become relevant and are investigated in this paper. For this purpose, in a first step the analytical design method from [1] is expanded and compared to literature values and finite element analysis. It shows sufficient agreement to both. Furthermore, it is extended to encompass propeller boundary conditions to evaluate the influence of different power levels for distributed propulsion, diameter limits and torque-speed-splits on efficiency, power density and winding choice.