Toward more electric powertrains in aircraft: Technical challenges and advancements

TLDR

Hybrid, all‑electric, and turboelectric powertrain architectures are examined, with hybrid and all‑electric options limited by current energy‑storage density, while turboelectric systems with distributed propulsion and boundary‑layer ingestion are poised to lead the transition. The article reviews the technological challenges and opportunities that impede the adoption of more electric powertrains in aircraft. Key enabling components—high‑power‑density electric machines, power converters, and their thermal management—are analyzed, along with the potential of higher‑voltage systems to improve fuel efficiency and power density. Based on the review, a projected roadmap outlining technology targets for batteries, machines, and converters toward future aircraft prototypes is presented.

Abstract

The main purpose of this article is to provide an instructive review of the technological challenges hindering the road toward more electric powertrains in aircraft. Hybrid, all-electric, and turboelectric powertrain architectures are discussed as possible fuel consumption and weight reduction solutions. Among these architectures, the short-term implementation of hybrid and all-electric architectures is limited, particularly for large-capacity aircraft due to the low energy/power density levels achievable by state-of-the-art electrical energy storage systems. Conversely, turboelectric architectures with advanced distributed propulsion and boundary layer ingestion are set to lead the efforts toward more electric powertrains. At the center of this transition, power converters and high-power density electric machines, i.e., electric motors and generators, and their corresponding thermal management systems are analyzed as the key devices enabling the more electric powertrain. Moreover, to further increase the fuel efficiency and power density of the aircraft, the benefits and challenges of implementing higher voltage powertrains are described. Lastly, based on the findings collected in this article, the projected roadmap toward more electric aircraft powertrains is presented. Herein, the individual targets for each technology, i.e., batteries, electric machines, and power converters, and how they translate to future aircraft prototypes are illustrated.