Investigation of Electro-mechanical Interaction and Active Protection in More Electric Aircrafts

More electric aircraft rely on electrical starter generators to start their engines and produce electricity once running. The aero engine will be connected to the starter generators via flexible shafts and gears, which will induce electro-mechanical interaction and torsional vibration in the mechanism. In the driving mode, sudden engine acceleration can cause torsional stresses, whereas in the generating mode, electrical load transients cause torsional stresses. Continuous torsional twisting within the powertrain can cause failures; therefore, active protection schemes are required to increase the reliability. In this paper, an active protection scheme based on shaft torque is proposed to protect and enhance the reliability of aerostarter generator systems, and the controller design is described. The newly introduced control algorithm can effectively increase the attenuation coefficient of the first natural frequency and substantially decrease the torsional stresses. The efficacy of the controller is demonstrated through simulations and experimental testing.