Full Bridge DC-DC Step-Down Converter With ZVZCS PWM Control Scheme

Full Bridge (FB) DC–DC converter is an attractive topology for high power level applications. A new Zero-Voltage and ZeroCurrent-Switching (ZVZCS) Full-Bridge (FB) Pulse Width Modulation (PWM) converter is proposed to improve the performance. In this converter, all switches must be ON or OFF only either voltage across switch or current through switch is zero. By adding a secondary active clamp and controlling the clamp switch moderately, ZVS (for leading-leg switches) and ZCS (for lagging-leg switches) are achieved without adding any lossy components or the saturable reactor. Many advantages including simple circuit topology, high efficiency, and low cost make the new converter attractive for high-voltage and high-power (>10 kW) applications. The principle of operation is explained and analyzed. The features and design considerations of the new converter are also illustrated. Finally the full bridge DC-DC step-down converter is simulated with the help of MATLAB simulink.