Comparative performance evaluation between the S4R and the S3R regulated bus topologies

The S3R and S4R space power converter topologies are shown to be suitable for regulated bus power systems. The S3R topology has been used in space applications for several decades, mainly in GEO projects. However, the power involved in actual spacecraft reaching the tens of kW as well as the increasing demands of LEO applications requiring fast recharges of the batteries, show the limits of the capability of the S3R topology. A comparative performance evaluation of the two topologies is presented by the authors in this paper