Performance of coreless-winding axial-flux permanent-magnet generator with power output at 400 Hz, 3000 r/min

An axial-flux permanent-magnet machine (AFPM) topology with a coreless winding is proposed for generator units required aboard ships, aircraft or hybrid electric vehicles. In the proposed AFPM configuration, the winding consists of rhomboidal-shaped coils encapsulated in fiber-reinforced epoxy resin. The coils have a double-layer arrangement to leave space for a cooling water duct being used to remove heat directly from the interior surface of the winding. The overall machine structure is compact and lightweight and, due to the lack of an iron core, generator operation with power output at 400 Hz can be accomplished with high efficiency and acceptable voltage regulation. This paper discusses the basic design and construction of AFPM generators with coreless windings and experimental results taken from a 16-pole machine prototype rated 230 Nm, 3000 RPM are also reported.