Power conditioning units for high power geostationary satellites

To be competitive on the telecommunication commercial satellites market, the components of the electrical power subsystem (EPS) have to be more and more easily adaptable to the output power level and to the payloads specific characteristics. The design driving factors are not only that required modularity and adaptability, but also the electrical and mechanical performances and the manufacturing costs. The purpose of this paper is to present the two last generations of power conditioning units (PCUs) that were developed by Alcatel ETCA in this context. The first one was developed and “space” qualified in 1994 for telecommunication spacecraft of up to 6 kW. This equipment has already been selected by “Aerospatiale”, to fly on more than 12 telecommunication geostationary satellites (Spacebus 3000 platform). Furthermore, the power modules were also used on a large number of scientific spacecraft. The possibility of using two PCUs in a double bus architecture allows the available power to be increased by a factor 2. Then, our new generation of PCUs-still under development-is presented. The equipment, that should be fully “space” qualified by the end of 1998, is developed to answer to the continuous and important increase of the telecommunication satellites power demand, and to improve still further the modularity and cost aspects (full modular concept covering the range from 5 to 20 kW by step of 2.5 kW)