Hardware in the Loop Test of an Electric Aircraft Powertrain

Electric machines are attracting attention as potential alternatives to conventional aircraft powertrains. During the development process of an electric aircraft it is often necessary to test and analyze the entire powertrain or components before all interacting systems are physically available. The function and behavior of subsystems, which interact with the powertrain, have to be emulated at a test bench. The powertrain is subject to varying external conditions during flight, which effect the function of the subsystems. Environmental conditions and the characteristic behavior of the aircraft have to be considered. This paper studies the development of a hardware in the loop test (HIL test), which allows to emulate flight conditions on a test bed during powertrain testing. The HIL test is subsequently implemented and developed for the example of the touring motor glider FVA 30. A duty cycle is derived from an aircraft flight test case and used to simulate the aircraft behavior. The results of the HIL test indicate, that the aircraft will meet the specified flight performance goals, but also hint at high temperatures inside the v-shaped tail section, which requires further study and possibly additional cooling effort.