Dc-to-dc power conversion with high current output

Abstract

A DC-to-DC converter for high current outputs is provided having an input side circuit, including two converter bridges, and an output side circuit, including two diode rectifier configurations. The input and output circuits are preferably connected by a co-axial winding transformer (CWT). Switches in the input side bridges alternately connect and disconnect a DC input voltage to and from the primary side of the transformer. The waveform appearing on the secondary of the transformer is rectified by the output side rectifier configurations. A switched-in bias voltage in each input side converter bridge provides for reversal of the current in the bridge after the bridge is switched off, and before the other bridge is switched on. This current reversal allows a current in one of the rectifier configurations of the output side circuit to be brought softly to zero before being reversed biased by the switching on of the other converter bridge. Thus, a reverse recovery spike in the output circuit is avoided. For high current outputs, the CWT is preferably constructed of a copper tube secondary winding enclosing the primary windings. The rectifier configurations include multiple diodes arranged in symmetrical configurations for optimal sharing of the high output currents. Air and water cooling of the diode configurations and output bus bars is provided. The output side circuit assembly can be provided as an integrated unit which is attached between the CWT and the load attached to the converter output.