Modular converters analysis and design for the standardization of the power bus in satellites

Abstract

The power subsystem role in a satellite is to generate, store and distribute the electrical power to all the satellite subsystems. The energy is obtained from a solar array when solar energy is available and from a battery otherwise. Whilst the voltage levels in the electrical power bus are standardized to certain values, the voltage of the solar array is not. Therefore, all the converters in the power subsystem have to be redesigned for every new mission, increasing costs and development times. This work presents one possible approach to promote standardization at converter level in the power subsystem, minimizing, this way, the redesign for every new mission. The use of a modular DC transformer (DCX) or electronic transformer (ET) with straightforward interconnection capability (i.e. automatic voltage and power sharing) will be presented as a possible solution to keep the design of all the converters of the power subsystem unchanged between missions. The validation of this design has been carried out using a modular prototype for an input and output voltages of 56 V and 28 V respectively, for a rated power of 200 W (per module) and for a switching frequency of 400 kHz.