Electric Drives for Electric Green Taxiing Systems

This paper addresses the implementation of electric taxiing without the use of main engines by using electric propulsion of the landing gears. Substantial progress in this area has been achieved by Honeywell Aerospace and Safran in a joint initiative for developing an electric green taxiing system (eTaxi). Considerable analysis, design, fabrication, and testing have already been completed, which culminated in a demonstration at the Paris Air Show (PAS) in 2013. The eTaxi system has been installed on an A320 airplane that uses the auxiliary power unit (APU) to generate electric power to provide propulsion to two wheels of the main landing gear. The main advantages of such a system are reduction of fuel consumption and audio noise, reduction of CO2 , carbon and nitrous emissions, reduced engine foreign object damage (FOD) exposure and fast-turn time savings by elimination of the ground tractor for pushback operation. The electric drive system (EDS), which comprises an alternating current (AC)-to-direct current (DC) converter, a wheel actuation control unit (WACU) and a traction motor (TM), is the heart of the system. It performs high power conversion of electrical to mechanical energy. At least one EDS is required to perform eTaxi functions. In this paper, the focus will be on the EDS and its components. The following topics will be covered: Definition of the major requirements and functions of the system. The requirements and functions related to the three components AC-to-DC converter, the WACU, and the TM. Architectural options and trade study results. Various possible implementations at the component level, along with a description of optimizations. The interfaces between the major components. Environmental challenges and potential solutions. Cooling designs and thermal challenges in the light of installation difficulties. EMI and power quality management approaches. Control and protection methodology as a part of the EDS and beyond. Data from development testing. Results from the PAS demonstration. Analytical results and correlation to the test results. System performance, as a part of typical operational duty cycles.Cross Reference: