Choice of drive topologies for electrical actuation of aircraft flaps and slats

This paper discusses the choice of drive topologies for the electrical actuation of aircraft flaps and slats. The paper first discusses the potential benefits of replacing electro-hydraulic actuation with distributed electrical actuation of the flight control surfaces. It then demonstrates why fault tolerance is essential in order to meet the reliability requirements of these systems. A range of different modular drive structures are compared, examining performance requirements at all speeds. It is shown how a shorted phase will exert substantial braking torque at low speed, and this strongly influences the choice of drive topology.