Opportunities and Challenges for Electric-Drive Systems on Aircraft

Traditionally, aircraft systems have relied upon bleed air from the main engine as the primary energy source for environmental control systems (ECS) and anti-icing systems. With the next generation of engines, bleed air may not be available to the extent utilized in the past. Electric drive systems are now being considered as viable alternatives for ECS. Electric drives are also being considered for traditional hydraulic drives in applications such as engine fuel pumps, and flap actuators.

Several aspects of electric drive systems consisting of permanent-magnet motors (PMM's) and solid-state power electronics for the primary generation or secondary control of electric drives on aircraft are discussed in this paper. For power distribution, conventional 120/208-v, 3-phase, 400-Hz; 270-vdc, variable frequency/constant voltage, and variable frequency/variable voltage systems are the primary candidates. Specific examples on 270-vdc power generation, variable speed drives for an ECS compressor and fan motors, and a variable speed drive for an engine fuel pump system are also included. Many opportunities and challenges exist and are being acted upon. Together they provide the interest necessary for the timely development of the technology for electric drive systems on aircraft.