Analysis and Design of a Parallel Resonant Converter for Constant Current Input to Constant Voltage Output DC-DC Converter Over Wide Load Range

With long distance power distribution systems, constant current distribution is preferred over constant voltage due to robustness against cable voltage drop and cable faults. Multiple power converter modules that are connected in series in such a system either regulate their output current or voltage, as needed. With a constant current input, the input voltage of a converter is dependent on the load and this voltage varies over a wide range with the load. The design of a constant current input to constant voltage output converter is detailed in this paper. The parallel resonant converter (PRC) is proposed for this application to naturally maintain constant output voltage over a wide load range. The control method, zero voltage switching realization and design guidelines are presented. The proposed design is experimentally verified through testing of a designed PRC that regulates a constant output voltage of 120 V when connected to 1 A current source for a load range of 50 W to 450 W.