Analysis and Design of Wide Range Output Voltage Regulated Power Supply for Underwater Constant Input Current DC Distribution System

Constant current feed is preferred in long distance under-water power distribution networks due to robustness against cable impedance and faults. Multiple power converter modules connected in series along the distribution line either provide a regulated current or regulated voltage at their outputs. In this paper, an isolated parallel resonant converter based converter architecture is presented that provides wide range of regulated output voltage over wide load range using multiple transformer secondary windings and a combining circuit. Steady state analysis and design are presented to minimize component count and stress with high efficiency over the full desired operating range. A generalized design method is presented for such a converter to operate from constant dc current source to regulate its output voltage over 1:10 range with 1:10 load range for each output voltage setting. Finally, a hardware prototype has been built and tested to validate the design with 250 kHz switching frequency and a regulated output voltage that can vary between 80 V to 250 V over a load range of 50 W to 500 W. The converter is fed from a 1 A constant current source.