Cryogenic Inverter Design for Superconducting Electric Propulsion in Next Generation Aircraft

Inhalt:
The aviation industry is undergoing a transformation toward next-generation aircraft that comply with increasingly stringent emission regulations. A key trend in this transition is the adoption of hydrogenpowered aircraft, where hydrogen fuel cells emerge as the only viable solution for carrying large amounts of energy at low weight. Besides energy storage, energy conversion through power electronics presents a major challenge, as it requires highly efficient and lightweight systems operating in the multi-megawatt range. These demanding requirements are driving research toward new inverter technologies and alternative operating conditions, such as cryogenic environments, to enhance performance and efficiency. In this context, this paper explores advancements in cryogenic power electronics for electric propulsion systems, emphasizing the role of Gallium Nitride (GaN) semiconductors at cryogenic temperatures of 77 K. Operating in a 400V cryogenic environment, the system is optimized for handling high currents through the paralleling of multiple GaN devices. This approach significantly reduces conduction losses, enhancing overall efficiency and power density. The design and integration of a cryogenic inverter are discussed, with detailed insights into the challenges of managing high-current paths. Furthermore, the paper presents experimental measurements and proof of concept for these advancements in cryogenic power electronics.