Novel zero-voltage and zero-current-switching (ZVZCS) full bridge PWM converter with low output current ripple

A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) PWM converter with low output current ripple is presented. A simple auxiliary circuit added in the secondary provides ZVZCS conditions to primary switches, ZVS for leading-leg switches and ZCS for lagging-leg switches, as well as reducing the output current ripple (ideally zero ripple). The auxiliary circuit includes neither lossy components nor additional active switches which are demerits of the previously presented ZVZCS converters. Many advantages including simple circuit topology, high efficiency, low cost and low current ripple make the new converter attractive for high performance high power (>1 kW) applications. The principle of operation, features and design considerations are illustrated and verified on a 2.5 kW, 100 kHz IGBT based experimental circuit.