Electronic power supply design for Sathyabama University Nano Satellite

This paper presents the practical and theoretical design of the power supply unit (PSU) of the Sathyabama University Nano Satellite. The solar arrays are configured such that the cells of each side on the satellite are connected in series and the four sides are connected in parallel. This configuration has been chosen, because it was found that it is the best trade off between ease of maximum power point tracking(MPPT) and to improve the converter performance. The diodes protect the cells from conducting a reverse current. The battery charge controller acts as a central unit of the electronic subsystem, it takes care of charging the battery unit. It basically transfers power from solar panel to the battery at unregulated bus. The choice of battery configuration and capacity is calculated on the basis of orbital calculation. This battery is also responsible for voltage control of the intermediate power bus between the two converters. The batteries keep the average voltage in the range 6.0-8.4V. This is used to convert the intermediate bus voltage to 5v and 3.3v bus levels for the other subsystem. The simulation results of various converters are shown.