Composite Converter Combined APFC with Switched-capacitor Converter

Abstract

To reduce switch numbers and voltage stress in semiconductor devices, this paper proposes a novel single-phase converter combined Active Power Factor Correction (APFC) with switched-capacitor converter. In addition, dynamic voltage regulation and voltage gain are improved by integrating the boost converter and switching capacitor cells. The interstage bulk capacitor is no longer needed. An average current control with redistribution of voltage in cells is proposed to obtain voltage lift ability of the switching capacitor cells and maintain a high-power factor. To study and verify the proposed converter preliminarily, theoretical analysis and simulation are presented in the paper. Furthermore, a 500 W prototype with two different configurations is built for experimental verification. The proposed converter can reach 95.62% of maximum efficiency, 0.99 of power factor, and 3.55% of THD with 600 V output voltage, simultaneously.