Design of a High-Speed Wound-Field Synchronous Generator for the More Electric Aircraft

Wound-field synchronous machines are widely used as generators in various applications. The main advantage over permanent magnet synchronous machines (PMSMs) consists in the possibility to control the field current, thus also achieving a good fault management capability. However, PMSMs can achieve higher power density and efficiency levels, making them attractive on board of aircraft. In fact, the surface-mounted PMSMs with sleeve are also pretty suited for high speed operation, whereas wound-field machines featuring salient poles are more challenging to be designed for such conditions.In this paper, the design of a high-speed wound-field synchronous generator is undertaken using a multi-disciplinary approach, aiming to achieve a relatively high fault tolerance and a power density value suitable for the "more electric aircraft" applications. The electromagnetic and thermal aspects are approached using common materials and cooling systems to minimize the costs, whereas the high speed operation requirement is addressed by a suited rotor retaining system. Simulation results based on FE analysis are reported to validate the proposed design.