GaN FET based CubeSat Electrical Power System

This paper deals with the development of high efficiency, compact and flexible Electrical Power System (EPS) for a Cube Satellite (CubeSat). The EPS is responsible for harnessing power from solar panels, battery charging and multi-domain voltage output regulation within the CubeSat. This work builds upon the results and learnings obtained from an EPS which uses Silicon MOSFETs. The hardware and software aspects of the development of such photovoltaic battery based power management systems are examined. The introduction of digital controller provides flexibility and intelligence but also introduces controller design challenges with simultaneous execution of multiple control loops. The EPS behaves like a standalone photo-voltaic battery charging system that harnesses solar energy to charge the battery banks. This entails the development of maximum power point tracking techniques as well as battery charging methods such as constant-current/constant-voltage charging. A dual loop control methodology with output current control is implemented to regulate the output current when charging the battery. This new EPS uses GaN FETs with an aim to increase efficiency and have all the functionalities of its silicon counterpart in smaller dimensions.