Design Optimization of a Starter Generator for More Sustainable High Power Density Aerospace Applications

The surface-mounted permanent magnet synchronous motor has found widespread use across various sectors, owing to its outstanding characteristics of torque density, efficiency and ease of control. These features, particularly crucial in the aviation field, make this type of machine highly desirable, especially in fixed-speed applications such as single-speed starter-generators. Additional performance metrics usually required nowadays in transportation are the sustainability and the overall environmental impact of components and systems. In this context, this paper proposes the design of a surface-mounted permanent magnet synchronous motor for a fixed-speed starter-generator, emphasizing all these different performance requirements. The design process is based on finite element (FE) optimizations, achieving a number of possible optimal configurations from an electromagnetic point of view, but giving then priority to the most environmentally friendly solutions. The outputs under examination are efficiency, power density, total harmonic distortion, torque ripple, copper and permanent magnet quantities, and temperatures. A motor characterized by a power density exceeding 2,3 kW/kg, 98% efficiency, and reduced copper and permanent magnet content is obtained.