Design and control strategy of a two-phase brushless exciter for three-stage starter/generator

The structure and control strategy of a novel two-phase brushless exciter were first proposed in this paper to solve the excitation problem of the main generator when three-stage brushless synchronous starter/generator starts up. Two-phase symmetrical winding was adopted as the field winding of the exciter, and was supplied with two-phase AC or DC by a two-phase inverter. This new exciter and control strategy have the advantages of high excitation efficiency and easy control compared with traditional single-phase and three-phase AC excitation strategy. A two-phase brushless exciter prototype, based on an existing exciter in three-stage starter/generator, was designed and analyzed using FEA. Simulation and experimental results verified the feasibility and advantages of the novel two-phase brushless exciter and control strategy.