Design and Analysis of an Aviation Hybrid Excitation Starter Generator with Radial Additional Air-Gaps

With the continuous development of aircraft technology, the power density and safety of generators are required to be higher in the aircraft power system. This paper investigates a hybrid excitation starter generator with radial additional air-gaps (HESG-RAA), which has high power density, a wide flux-regulation range, and the ability to suppress short-circuit current. The topology design and equivalent magnetic circuit of the HESG-RAA are introduced. In addition, the electromagnetic performance of the investigated HESG-RAA is analyzed, including no-load characteristics, load characteristics, and short-circuit characteristics. The mechanical strength of the rotor of the HESG-RAA is analyzed at the highest speed. Finally, a 90 kW HESG prototype is manufactured, and the test results verified the effectiveness of the HESG-RAA structure and flux-regulation principle.