Implementation of an interleaved three-level ZVS converter

This paper presents the system analysis and circuit characteristics of an interleaved soft switching dc-dc converter. One auxiliary switch and one fast recovery diode are connected between the half-bridge leg and the middle point of split capacitors to generate three different voltage levels on the primary side of transformer. The zero voltage switching (ZVS) is achieved at the transition interval between power switches. The current doubler rectifier is adopted in the secondary side of transformer to reduce the current stress on the transformer secondary winding and achieve the ripple current cancellation on the output capacitor such that the sizes of the output chokes and capacitor are reduced. The interleaved PWM scheme is used to achieve load current sharing, reduce the ripple current on the input side and regulate the output voltage. Finally, experimental results based on a 500W (12V/42A) prototype are provided to verify the theoretical analysis and effectiveness of the proposed converter.