A Novel ZVZCS Converter Using Passive Clamp Circuit

A novel full-bridge phase-shift PWM ZVZCS(zero-voltage and zero-current switching)DC-DC converter using passive clamp circuit is proposed based on the characteristic of conventional full-bridge phase-shift PWM ZVZCS DC-DC converter.The converter can achieve zero-voltage-switching(ZVS)for leading-leg switches and zero-current-switching(ZCS)for lagging-leg switches effectively.The principle and operation modes of the converter are analyzed,and the necessary condition of soft switching is also analyzed.By using the passive clamp circuit,the proposed converter can reduce voltage stress in secondary side,and widen load range for soft switching.The losses of the auxiliary clamp circuit are very low.The proposed theory has been verified on a 0.8kW,60kHz experimental converter.The soft switching of lagging leg can be achieved in wide load range,so this converter is suitable for large power application where IGBT is used.