Analysis of parallel-connected zero-voltage- switching forward converter

Abstract

This paper presents a soft switching converter with interleaved pulse-width modulation (PWM) scheme. There are two circuit modules in the proposed converter to share the load current. The interleaved PWM scheme is adopted to control two converter modules such that the input and output ripple currents and the current stresses on power switches and transformer windings are reduced. In each converter module, two forward converters with active clamp technique are adopted to further reduce the ripple current on the output capacitor and decrease the current stresses on transformer windings. The gate signals of two power switches in each converter module are complementary each other in order to realize the zero voltage switching turn-on of switches at the transition interval. Thus, the switching losses and thermal stresses of the semiconductors and transformers are reduced. All of these features make the proposed converter suitable for the dc-dc converters with high output current. Finally, experiments based on a 600 W prototype are provided to verify the theoretical analysis.