Modeling and Control of a Charge/Discharge Unit of Electric Power System for Low Earth Orbit Satellites

The main role of batteries which used as a secondary power source in any spacecraft is to supply power to the satellite under the condition of shadow or the inability of solar-PV arrays to feed the satellite loads with power. In this paper, model and control of a charge/discharge unit (CDU) of the battery in low earth orbit satellites is developed. The proposed CDU control algorithm regulates the satellite bus voltage within the standardized levels. Furthermore, the CDU control is tested against various disturbances to verify the proper operation of the unit.