Output filter reduction with a combined linear-non-linear control

The transient performance of a DC power supply strongly depends on the loop design and output filter sizing. Most of the time, the finite loop bandwidth imposes the need of a large output filter capacitor in order to comply with the required regulation performance and stability margins. In space applications the linear conductance control principle has been used for a long time. It reduces the voltage regulator to a simple "first order" system, thus simplifying the analysis. In order to decrease the size of the output filter and to enhance the converter dynamic response, a modified control technique is proposed in this paper. This concept has been demonstrated on a buck converter and it can be used in space applications, where "three-domain control" is implemented for a regulated bus.