Detailed Design of a 250-kW Switched Reluctance Starter/Generator for an Aircraft Engine

The work reported in this paper has been conducted by General Electric Company and Sundstrand Corporation as part of a contract sponsored by the USAF, Wright Laboratories, and WPAFB under contract no. F33615-90-C-2052. The objective of this contract is to prove the feasibility of an integral starter/generator (IS/G) through the preliminary design stage and demonstrate the starter/generator technology in the externally-mounted version (EIS/G) using switched reluctance (SR) machine technology. This paper reports on the detailed design and analysis of the EIS/G. The analysis and design encompassed definition of requirements and constraints, electromagnetic design, thermal analysis, mechanical stress and fit analysis, bearing and critical speed analysis, and mechanical layout and packaging. The results show that when properly designed the SR machine has a very competitive power density when compared to existing aircraft secondary power generator, and that the machine is capable of meeting the application performance requirements.