Characterization of 650 V GaN transistors at cryogenic temperature in all-electric aircraft applications

With the growing electrification of aircraft, power electronics is playing an increasingly vital role in driving this transformation. It is expected that some all-electric aircraft to utilizes liquid hydrogen (LH2) as power fuel as well as coolant, which opens the possibility of utilizing cryogenic power electronics which offers higher efficiency and faster switching speeds than its room-temperature counterpart. Literature has shown the most efficient semiconductor switches at cryogenic temperatures is gallium nitride (GaN). Thus this paper focuses on studying the characteristics of 650 V GaN transistor at room temperature and cryogenic temperature at 77 K. Forward and breakdown voltage tests are performed to characterize the device. With the extracted device characteristics, a buck converter is simulated to estimate its efficiency and room and cryogenic temperatures.