Design and Implementation of a GaN-Based, Cascaded Isolated DC-DC Converter for Satellite Applications

CubeSat and SmallSat class spacecrafts are gaining popularity and becoming compelling alternatives to traditional, heavy-weight satellites. Power converters for these satellite applications are required to be lightweight and highly efficient. This work proposes a two-stage power converter comprised of a cascaded boost stage and dual active bridge (DAB) stage for satellite applications. The design achieves high performance by utilizing GaN transistors, which are able to withstand radiation conditions in space, as well as planar magnetics to reduce the powerstage volume and mass. A 150 W hardware prototype boasting efficiencies above 92 % is built to demonstrate the merit of this cascaded topology for use in low-voltage space systems.