부산대학교 도서관

This article presents an integrated single-stage single-switch (4S) ac–dc system for LED delivering a high input power factor (IPF) and regulated output. The proposed topology integrates a power factor correction (PFC) converter with a high-frequency dc–dc converter, driven by a modified front-end single-phase Vienna rectifier. The integration results in a single switch prototype, thus decreasing the cost and complexity of the control circuit. The use of fewer diodes in the front-end rectifier reduces the nonlinearity in the proposed topology. First-stage filter capacitors offer a better input dynamics to the PFC stage. The proposed (4S) prototype offers less component counts and minimal input current harmonics. The theoretical and mathematical analysis of the proposed topology is presented. Finally, the proposed (4S) ac–dc system analysis and simulation results have been verified with a 50 W/60 V prototype depicting an IPF of 0.997, total harmonic distortion (THD) of 3.96%, and an efficiency of 90.8%. The presented experimental results coincided with the analysis and comply with IEC61000-3-2 standards.