Barriers and Challenges Going from Conventional to Cryogenic Superconducting Propulsion for Hybrid and All-Electric Aircrafts

Abstract

The development of electric aircraft is becoming an important technology for achieving the goals set by the European Commission for the reduction of gases emissions by 2050 in the aeronautical transportation system. However, there is a technology gap between the current values of specific power in commercial electric machines and those required for aeronautical applications. Therefore, the search for alternative materials and non-conventional designs is mandatory. One emergent solution is using superconducting machines and systems to overcome the current limits of conventional electrical machines. This work reviews the new hybrid and all-electric aircraft tendencies, complementing it with recent research on the design and development of high specific power superconducting machines. This includes the main topologies for hybrid and all-electric aircraft, with an overview of the ongoing worldwide projects of these aircraft types, systematizing the main characteristics of their propulsion systems. It also includes the research on superconducting machines to achieve high specific power and consider the impact on the redesign of aircraft systems, the electrical, cooling, and fuel source systems.

Alternative analytical models for HTS tapes considering their AC hysteretic and resistive losses

“…Considering I m = √ 2I rms , the equivalent HTS tape resistance per meter can be defined as in (25) and (26), for the elliptical and thin-strip HTS tapes, respectively. The HTS tape's losses can be computed using P total = R eq I rms 2 , dividing equations ( 13)-( 16) by I rms 2 . Using the extended-Norris model, for 1st generation elliptical superconductors:…”

“…The use of high-temperature superconductors (HTS) in electrical machines has been identified as a potential technology to unlock the further electrification of transportation systems [1,2], specifically in aeronautical transportation [3][4][5][6][7]. Using HTS materials, such as bulks and tapes, fully [3] and partial [5] superconducting (SC) electric machines are being designed * Author to whom any correspondence should be addressed.…”

Recent Developments in Electrical Machine Design for the Electrification of Industrial and Transportation Systems

“…Another important research topic is the development of cryogenic machines with conventional or superconducting materials [25,26]. These have also been identified as potential solutions to achieve the high specific power/torque requirements for future electric aircraft [27]. In [25], the performance of two induction machines is investigated and compared when operating at room temperature, at cryogenic conditions, and with superconductors in the rotor.…”

GaN-based cryogenic temperature power electronics for superconducting motors in cryo-electric aircraft

“…The LH 2 , which would be stored below −253 • C, can cool a HTS motor below its critical temperature, so it can serve as both a coolant and fuel. Similar architectures have been proposed in [7][8][9][10], where the Airbus 'ASCEND' [7] program is creating a demonstrator for this dual purpose of LH 2 . In these powertrains, LH 2 cools the HTS motor and HTS cables, and H 2 boiled off from losses is used to cool the power electronics.…”