Interleaved Boost-Flyback Converter with Boundary Conduction Mode for Power Factor Correction

Abstract

This paper presents a new interleaved pulse-width modulation (PWM) boost-flyback converter to achieve power factor correction (PFC) and regulate DC bus voltage. The adopted boost-flyback converter has a high voltage conversion ratio to overcome the limit of conventional boost or buck-boost converter with narrow turn-off period. The proposed converter has wide turn-off period compared with a conventional boost converter. Thus, the higher output voltage can be achieved in the proposed converter. The interleaved PWM can further reduce the input and output ripple currents such that the sizes of inductor and capacitor are reduced. Since boundary conduction mode (BCM) is adopted to achieve power factor correction, power switches are turned on at zero current switching (ZCS) and switching losses are reduced. The circuit configuration, principle operation, system analysis, and design consideration of the proposed converter are presented in detail. Finally, experiments conducted on a laboratory prototype rated at 500W were presented to verify the effectiveness of the converter.

Double boost‐flyback converter

“…Many of these sources operate with low voltage levels, i.e. from 10 to 50 V. Therefore, it is common to use a high-gain dc-dc converter [1][2][3][4][5] to allow either connection to the utility grid or even an isolated application powering a conventional load. It is well known that a conventional utility grid operates with voltage levels from 110 to 230 V (RMS) .…”

“…On the other hand, interleaving techniques allow greater power processing in converters, because they divide the current stresses at the input and this reduces the current ripple drained from the source [4,5]. As for disadvantages, they involve large amounts of components, which increase the cost, and they do not provide extra gain.…”