Front-end converter system for distributed power supply

A power converter system has been developed for application as a front-end power converter for distributed power supplies. The system consists of a cascade connection of a novel three-phase rectifier stage with a push-pull buck power converter as a first stage and a resonant half-bridge power converter as a second stage. Analysis of the converter has been derived and a design procedure has been formulated. The final converter design has been simulated using the circuit simulation program PSPICE. Finally, a full-size prototype converter has been built and tested to prove theoretical results. The developed converter system provides a transformer-isolated output voltage of 48 V when operated off-line from a 415 V three-phase mains supply. The maximum output power delivered to the load is 2.5 kW. The converter provides nearly sinusoidal input current waveforms with approximately unity power factor drawn from all three phases of the three-phase supply