Patent ID: 7408794

Claim:
A dc-to-dc power converter comprising: a transformer; a primary dc power circuit and a secondary dc power circuit coupled through the isolation transformer; the primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals; a switching controller operable for providing the gating signals to the resonant switching devices in the primary and secondary circuits to control power flow between the primary and secondary dc power circuits; wherein the switching controller operates to control power flow from the primary dc power to the secondary dc power circuit, or from the secondary dc power circuit to the primary dc power circuit by providing gating signals to control a phase shift between a primary voltage in the primary dc power circuit and a secondary voltage in secondary dc power circuit; wherein the primary dc power circuit includes at least two low voltage buses to provide a plurality of voltages through the primary dc power circuit; and wherein the primary dc power circuit does not include filtering capacitors or bus inductors connected to the two low voltage buses.