Design procedure and modeling of high power, high performance, zero-voltage zero-current switched, full-bridge PWM converter

A general design procedure for the high power, high performance, zero-voltage zero-current switched full-bridge (ZVZCS-FB), PWM power converter is presented. Average and small-signal models of the power converter are developed. The former shows a decrease in loss of duty-cycle with increasing output power, whereas the latter reveals negative damping effects. Both effects are produced by the interaction between blocking capacitor and saturable reactor in the primary of the output transformer. Validation of design equations and model predictions is accomplished through numerical solution of steady-state nonlinear equations and experimental results from a 10 kW, multi-module, ZVZCS power converter operating at 100 kHz, and featuring power sharing and interleaving.