This thesis describes the design and implementation of an electronic power system for the CubeSTAR satellite. The main task of the power system is to supply continuous power to the satellite in orbit. The power system consists of several parts: Solar cells, battery chargers, battery pack, power distribution bus, sensors monitoring different parts of the system and a microcontroller used to control the system.
The solar cells are used to generate power to the satellite and charge the battery pack. The battery charging system is based on the SPV1040 charger with embedded maximum power point tracking. A charger efficiency of 90% has been achieved. The battery pack is made of six lithium iron phosphate battery cells connected in parallel. It has been decided to distribute unregulated power. This leaves each subsystem responsible for regulating the power with respect to their requirements. From the estimated power budget, the total average power consumption of the satellite should be below 2 W. The electronic power system itself uses an average power of 66 mW.
A microcontroller is used to control the power system and it is a slave unit receiving commands from the satellite main processor. The microcontroller gathers all sensor data and prepares the data for transmission to the ground station. There are various voltage, current and temperature sensors implemented for monitoring the power system.