Modeling, Analysis and Design of 15kW Zero-Voltage Zero-Current Switched Full Bridge PWM Converter

This paper presents the modeling and design of a novel ZVZC FB-PWM converter. Compared to the traditional topology which employs a saturated inductor to block the reverse current in order to achieve ZCS for the lagging leg, a novel one using two diodes in series with the lagging leg is adopted. Both the duty ratio loss is reduced and the efficiency is improved, which further reliefs the problem of thermal handling caused by the saturated inductor. What´s more, better stability and dynamic behavior are acquired. A complete small-signal model for the novel ZVZC FB-PWM converter is developed. Validation of design of equation and model prediction is accomplished through numerical solutions of steady-state nonlinear equations and experimental results of a 15 kW module converter operating at 20 kHz.