The Tsinghua 1 Micro satellite, the first satellite made by Tsinghua University, was launched in 2000. The power system of the Tsinghua 1 Micro satellite is one of the most important subsystems. It provides all the power for the satellite platform and the payloads. The power system design includes the regulation, protection and distribution of a 4×35 W solar array and 7 Ah NiCd batteries. This subsystem essentially offers two buses: an unregulated 14 V bus and a regulated 5 V bus. 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. The Tsinghua 1 Micro satellite power system provides an efficient, flexible, reliable, and cost effective solution for small satellites in low earth orbit. A better maximum power point tracking method has been used to increase reliability margins and to increase the efficiency of the power system. The power system reliability was evaluated using several different tests, such as the power board test, the assembly integrate test (AIT), the electromagnetic compatibility (EMC) test and the thermal vacuum test (TVT).
