Dynamic Modeling of an Active Current Doubler Rectifier Applied to Resonant Converters

A current doubler rectifier typically uses only two diodes, i.e. single quadrant passive switches, at the output stage of isolated dc-dc converters and, thus, is not able to actively define the voltage at the load port. The active current doubler rectifier (ACD) uses current unidirectional two-quadrant switches in order to provide such control for applications that might require it. However, literature on the models that are able to effectively predict the dynamics of such active rectifiers is lacking. This, the ACD is modeled here based on dynamic phasors in a state space form for its resonant operation. The developed models show how the switching phase affects this rectifier currents and voltages, and provides an important tool to design control loops. An LC resonant tank is exemplarily used with the ACD. However, the procedure can be applied to other types of topologies. Design and exnerimental results corroborate the modeling.