Sizing, Design, and Modelling of Aerospace Electric Drive System with Long Feeder Cables

Abstract

The aviation industry is tending towards more electric aircraft, replacing conventionally pneumatic, hydraulic, and mechanical systems with electrical solutions. The electrification of actuators is motivated by increased efficiency, reduced maintenance and potential mass savings. Special considerations need to be made when designing an aerospace application electric drive system with long feeder cables. For a given actuation requirement, mass and volume need to be minimized while obeying thermal and reliability constraints. Fast switched high dV/dt voltages applied to a cable with poor machine-cable impedance matching can cause high-amplitude high-frequency voltage oscillations, potentially leading to corona discharge, insulation failure, high common-mode, differential-mode currents, bearing currents, and reduced lifetime of system. Mitigation of these voltage oscillations can reduce and/or eliminate the problems associated with it. In this paper, the details of a high-level electric drive system design tool for component sizing and modelling is described. The designed systems mass, volume, thermals, reliability and performance figures are produced. To demonstrate the design tool, the results of a hypothetical 3kW centralized electric drive system case study is presented. A LC inverter filter is used to mitigate long feeder cables.