Speaker
Description
The aviation industry has committed to a long-term global goal of net-zero carbon emissions by 2050. Zero Emission Sustainable Transportation 1 (ZEST1), which was funded by UK's Aerospace Technology Institute and consorted by 10 partners led by Airbus, aims to accelerate technology breakthroughs to enable zero emission commercial aircraft by 2030. Within the consortium, the University of Strathclyde is responsible for the delivery of a high-temperature superconducting (HTS) machine and its motor drive (two identical 100kW inverters in parallel connection). The inverters will be operated in a cryogenic environment for reasons of not only the reduced heat leak-in to cryostat, but the minimized energy loss of power electronics, which will eventually enhance the power density and the efficiency of the powertrain. In general, the design and the assembly phase has been completed. The cryogenic inverters use three-level neutral-point-clamped topology. Various electronic components including power semiconductor devices, magnetic cores, capacitors, resistors, operational amplifiers, digital isolators and differential transceivers are characterized at cryogenic temperature for optimal screening. Cryogenic conditioning circuits and isolated gate drivers are custom designed to enable high-voltage high-side gate drive in cryogenic temperature environments. A cryostat is designed as well for immersing the inverters in liquid nitrogen. The input DC voltage has a nominal value of 735V. The cryogenic inverters supply three-phase ac line voltage with RMS value of 520 V and frequency ranges between 0 Hz and 100 Hz. One phase of the inverter, i.e., a three-level neutral-point-clamped switching stage, has been successfully tested under input voltage up to 700V. The three-phase inverter will be tested in room and cryogenic temperature by the mid of 2025.
