Assessment of (hybrid)-electric drive-train architectures for future aircraft applications

Future regional aircraft and propulsion systems will have to address both a growing market and stricter environmental constraints. Besides the increase of component efficiencies, the technological transformation from conventional to (hybrid)-electric propulsion systems represents a paradigm shift with great potential for the aviation industry. In this context, economic, market-relevant as well as technological boundary conditions for the electrical and mechanical components are developed in this paper for a reference regional aircraft and are based on current research results from different institutions. The propulsion performance analysis of a conventional turboprop is compared and evaluated with a serial-hybrid and a fully-electric configuration (both battery-electric), status today as well as status similar to 2035, as an example, whereby the presented process can also be applied to other hybrid configurations too. An energy-optimised propulsion and operating concept is derived with regard to minimum resulting system weight. The results of this analysis help to define necessary boundary conditions for future subsystem investigations and identify key research items, especially in the field of the battery.