Low Temperature Investigation of a Cascode GaN based Resonant Bi-directional DC/DC Converter

Cryogenic power electronics has been regarded as the next step to improve the system efficiency and power density. Moreover, some semiconductors have been reported to have improved performances under cryogenic temperatures. Bi-directional DC/DC converter is often required to interface between different energy sources. In this article, the cryogenic performances of the Cascode GaN based bi-directional DC/DC converter are reported. The individual components performances are characterized under low temperatures, including Cascode GaN FET, gate driver, magnetic component, and capacitor. A significant conduction loss reduction is expected due to the reduction of on-state resistance under low temperatures. The XFlux core are implemented as the magnetic components due to its stable core loss and permeability performances. The polypropylene film capacitor is selected for both the filer capacitor and resonant capacitor owning to its stable capacitance and dissipation factor performances under low temepratures. Then, a 400 W experimental prototype was tested. The results demonstrate that the evaluated Cascode GaN based converter has stable efficiency performance under low temperatures. Efficiency improvement is observed under light load operation condition. Overall, the Cascode GaN based resonant converter would be a feasible solution for cryogenic applications.