Integrated generator for more electric engine: Design and testing of a scaled size prototype

In this paper the main design characteristics of a scaled-size prototype of an integrated generator for More Electric Engine (MEE) application are presented. The reference electrical machine is a surface mounted PM machine directly integrated inside the aircraft main gas turbine engine. Therefore, as for the reference machine, the designed scaled-size prototype is characterized by an annulus shape outer rotor structure and it is cooled by air flowing through the airgap. To satisfy the fault-tolerant requirements imposed by the aerospace application, the stator winding is constituted by multiphase single-layer non-overlapping fractional-slot concentrated windings. In order to validate the designed machine, the experimental results of tests conducted on the prototype are reported. Among these ones, particular interest is focused on the cooling capabilities of the cooling air which flow through the machine airgap. Furthermore, based on the reduced scale prototype experience, some considerations and the main design characteristics of the full-size machine design are reported too.