Energy efficient design and implementation of electric machines in air transport propulsion system

Following the global trend of carbon neutrality, green sustainable air transport becomes a hot topic in relevant area of applied energy. Electrified air transport propulsion system (EATPS) has received wide research interest since it can completely replace jet engines, exclude fossil fuel supply, and eliminate carbon emission during flight. As the core component in EATPS, electric machine raises a natural yet practical challenge of energy-efficient design (EED) and operation. This article is devoted to conducting a technical overview on EED measures of electric machines and their future potential for aviation propulsion application. While literatures have indicated some challenges and opportunities for efficient motors, there is still a lack of knowledge and a thorough picture on design considerations and specific EED measures of such motors regarding the performance demands imposed by EATPS. Holding the aim to promote future electrified propulsion and to narrow the technological knowledge gap, this study thoroughly investigates motor efficiency-related R&D items including field calculation, loss prediction, power dense design, speed range widening, advanced material application, efficient cooling strategies, etc. In the end, it provides recommendations, guidelines for designers, and prospects.