Power conversion apparatus for DC/DC conversion using dual active bridges

DC/DC static power conversion apparatus comprising:

• (a) an input converter adapted to receive a DC source voltage from a DC source and containing a plurality of active gate controlled gate turn-off switching elements connected in a bridge configuration to allow the DC input voltage to be converted to an AC output voltage at the output of the converter;
• (b) a transformer with primary and secondary windings and leakage inductance, the primary connected to receive the output of the input converter;
• (c) an output converter connected to the secondary of the transformer for converting the AC voltage at the secondary of the transformer to a DC output voltage at the output of the converter, the output converter containing a plurality of gate controlled active gate turn-off switching elements arranged in a bridge configuration to allow the AC input to be converted to the DC output voltage from the converter;
• and
• (d) control means connected to the gates of the input converter switching elements and the gates of the output converter switching elements for controlling the input converter switching elements in a soft-switched manner to convert the DC source voltage to an AC output voltage at a selected frequency at the output of the input converter, and for controlling the switching of the output converter switching elements in a soft-switched manner to convert the AC input voltage at the selected frequency at the input of the output converter to a DC voltage at the output of the output converter, the switching of the input converter and output converter switching elements being controlled to provide a phase difference between the voltages at the primary and secondary of the transformer which yields a desired output voltage and power level from the output converter.