Design and analysis of three-port DC/DC converters for satellite platform power system

Mass is one of the most important design constraints for the satellite power system. In order to achieve maximal solar power harvesting, battery charge/discharge control, and bus voltage regulation, normally several independent converters will be required, resulting in a heavy and bulky power system. This paper proposes a compact and efficient solution by using integrated three-port converter to achieve all above-mentioned functions within one single converter, therefore much lighter and smaller than the conventional system. The three-port topology is obtained by simply adding a switch and a diode to the conventional half-bridge converter. Moreover, zero-voltage switching is realized for all switches to reduce switching loss. The topology and circuit design is discussed in detail. In addition, the system construction is introduced, which adopts a distributed structure to obtain redundancy and maximize solar power harvesting for each individual PV panel. The proposed design is verified by experimental results.