Integrated Buck-Boost-Quadratic Buck PFC Rectifier for Universal Input Applications

This paper presents a new single-stage single-switch (S-4) high power factor correction (PFC) ac/dc converter suitable for low-power applications (< 150 W) with a universal input voltage range (90-265 V-rms). The proposed topology integrates a buck-boost input current shaper with a quadratic buck converter. As a result, the proposed converter can operate with larger duty cycles compared to the exiting S-4 topologies; hence, making them suitable for high-frequency nonisolated applications. Additional features are gained when both the input PFC buck-boost cell and the quadratic buck cell operate in discontinuous conduction mode (DCM). These features include low semiconductor voltage stress, zero-current switch at turn-ON, and simple control with a fast well-regulated output voltage. A detailed circuit analysis is performed to derive the design equations. The feasibility of the converter is confirmed with results obtained from a computer simulation and an experimental prototype.