Electric Power Transfer Concept for Enhanced Performance of the More Electric Engine

Abstract

In future electrified aircraft, multispool more electric engines (MEEs) are expected to be equipped with electric generators connected to each shaft for power offtake and supplying onboard electrical loads. These can be interfaced to a common high-voltage DC bus architecture via power electronic converters. Such system architecture enables the establishment of an “electrical bridge” to circulate the desired amount of power between the engine shafts, and decouple their speeds. This paper introduces the possible benefits from the electric power transfer (EPT) for engine performance and scrutinizes a novel EPT-adopted design (EPTAD) for future MEEs. For this purpose, a zero-dimensional (0D) engine model has been developed by using the intercomponent-volume (ICV) method. By using the engine model, the CFM56-3 engine is redesigned to realize the EPTAD. Comparing the simulation results for the EPTAD and baseline CFM56-3 engines shows significant improvement for engine performance in terms of specific fuel consumption (SFC) and surge margin (SM), mainly at cruise (CR) condition. Results show that almost 3.2% and 2.2% of fuel burn reduction is achieved for the short- and medium-haul flights, respectively, with a 1150 kW EPT system. It is also shown that variable bleed valves (VBVs) can be eliminated in the EPTAD engine with a 1150 kW EPT system.