High frequency, high density power conversion system

Claim 1

A high-frequency, double-ended, low-loss, high power density power converter, comprising: three input terminals for receiving voltage input; first and second transistors connected source-to-drain at a first node in series across the two outer input terminals, each said transistor having an inherent parasitic capacitance; first and second capacitors connected at a second node in series across the two outer input terminals, the second node comprising the third input terminal; a low-leakage inductance transformer for coupling power to an output, one side of the transformer primary connected to the first node, said transformer having a leakage inductance of no more than 1 uH so that said leakage inductance has a negligible effect on resonance; a dedicated inductor connected in series with said transformer primary between the first and second nodes, said inductor and the inherent transistor capacitance thus together forming a resonant energy storage tank on the transformer primary side of the power converter for shifting the voltage input into a sinusoidal waveform, and for transferring power stored in said transistors by reason of the inherent capacitance of said transistors; wherein said transformer has a magnetizing inductance at least one hundred times greater than the inductance of said dedicated inductor, said transformer thus having a large impedance which causes it to act as an open circuit and thus have a negligible effect on resonance; and means for switching between said transistors at the resonant frequency of said resonant energy storage tank to provide a sinusoidal output current pulse to the transformer primary at the transistor switching rate and to utilize energy stored in the inherent transistor capacitance.