Optimized design of a multiphase induction machine for an open rotor aero-engine shaft-line-embedded starter/generator

The aerospace world has found in the progressive electrification of on-board services the way to improve aircraft efficiency, reliability and maintainability. The resulting step change in aircraft electrical loads is impacting on the electrical generation and distribution systems. On the other hand the fuel saving targets is drawing the attention toward new architectures such as counter rotating fans and open rotor jet engines. The integration of the generator on shaft of this kind of engine challenges the electric machine designer in facing, at the same time, the harsh environment and high reliability requirements. The paper presents the design of multi-phase fault tolerant induction machine to be installed on the high pressure shaft of an open rotor jet engine. In particular, the proposed solution is a four-three-phase induction machine.