High Power Factor Interleaved Buck AC/DC Converter with Boundary Conduction Mode

摘要

This paper presents the system analysis and circuit implementation of high power factor interleaved buck AC/DC converter with boundary conduction mode (BCM) to achieve power factor correction (PFC) and regulate DC bus voltage. Two buck converter cells are driven in the interleaved fashion. The current ripples at input and output sides are partially cancelled and the current stresses of semiconductors can be reduced. The BCM operation is adopted to control switches such that the input current is followed the AC source voltage with a nearly unity power factor. The buck AC/DC converter improves the circuit efficiency across the wide line ranges and load conditions compared to the efficiency of boost PFC circuit. The low output voltage can also reduce the voltage stress of semiconductors in the second DC/DC converter. Finally, experiments taken from a 5 00W prototype are presented to verify the effectiveness of the proposed converter.