An Active Control Excitation Method of Three-Stage Brushless Synchronous Starter/Generator in Electric Starting Mode for MEA

More electric aircraft (MEA) and all electric aircraft (AEA) are the development trends of new generation aircraft. With the increasing dependency on electrical power in MEA, dual-function electrical machinery technology is the inevitable trend of the aircraft engine-driven generator. This paper proposes an active control excitation method to the S/G to produce enough electromagnetic torque and realize the smooth electric starting of aircraft engine. The main DC/AC invertion module in the DC/AC inverter supplies a three-phase current to the main S/G stator windings. The module adopts an active control method that the current is adjusted by a reference three-phase current which varies as a function of rotor shaft position and rotation speed. Meanwhile, the exciter power supply module in the DC/AC inverter supplies a single-phase AC current to the auxiliary exciter stator winding. This part also adopts an active control method that a current hysteresis tracking control strategy is taken and the scheduled current is adjusted as a function of the rotor rotation speed. Simulation results verify the effectiveness of the electric starting excitation strategy. The two magnetic fields generated by the stator and rotor windings of the main S/G interacts each other which produces enough electromagnetic torque to drive the starter from the stationary state.