Performance evaluation of a 250 kW switched reluctance starter generator

This paper describes the system integration and performance evaluation testing of a high speed, 250 kW starter/generator [S/G] system used for starting and secondary electrical power extraction from an aircraft propulsion gas turbine. The effort described here is part a contract sponsored by the USAF, Wright Laboratories, WPAFB. The paper describes a switched reluctance [SR] machine which is operating both as a motor and generator in a speed range of 0 to 22,224 r.p.m. Additionally it is one of the highest rated motor/generator systems in the SR technology. The system employs two independent channels consisting of two groups of three phase windings, two three phase inverters, and two controllers and can provide two different power output buses for independent loading. The system hardware is described briefly followed by a detail description of the test results. These show some surprises with regards to single channel operating mode. A brief derivation and explanation of the findings is provided. The motor/generator system is planned to be part of a more electric aircraft power system.