Tsinghua-1 Micro-satellite power system architecture and design

Tsinghua-1 Micro-satellite is the first satellite made by Tsinghua University. It will be launched in 2000. The power system of Tsinghua-1 Micro-satellite is one of the most important subsystem. It provides all power for satellite platform and payloads from the mission's beginning to the end. We designed the regulation, protection and distribution of 4 X 35 W solar array power and the energy of 7 Ah NiCd batteries. This subsystem essentially offers two buses: unregulated 14 V and regulated 5 V. All distributed power lines to the users are protected by current tripping switches. In addition some essential loads, such as the Tele-command System, are supplied through fuses. Tsinghua-1 Microsatellite power system provides an efficient, flexible, reliable and cost-effective solution for small satellites in Low Earth Orbit. A better Maximum Power Point Tracking has been used to increase reliability margins and increase the efficiency of power system. Under taking several kinds of test, such as power board test, AIT(Assemble Integrate Test), EMC(Electro Magnetic Compatibility) test and TVT(Thermal Vacuum Test), the power system worked very well.