Patent ID: 6178099
Filing Date: 2001-01-23
Classification: H02M,Y02B

Abstract:
An optimal phase-shifted control for a resonant converter of a type comprising a full-bridge configuration of switching devices, a resonant tank circuit and an isolation transformer, the resonant tank circuit comprising a resonant inductance and a resonant capacitance, the optimal phase-shifted control comprising:means for monitoring resonant inductance current, resonant capacitance voltage and an output voltage; andmeans for operating the resonant converter at a super-resonant frequency and for implementing a control law for operating the resonant converter in a quasi-squarewave-with-maximum-coasting (QSWMC) mode such that operation proceeds along predetermined state trajectories with transitions therebetween determined by the control law in order to provide optimal turn on and turn off times for the switching devices, each state trajectory having a center determined by a forcing function voltage and a radius determined by the resonant inductance current and the resonant capacitance voltage.