Single‐stage single‐switch high power factor driving circuit for lighting applications

Abstract

Although compact fluorescent lamps (CFLs) have been in the market for a long time, many of them do not achieve the same power factor as the incandescent lamps do, which appears to be a significant problem for the utility with the current widespread use of CFLs for household lightings. A single-stage single-switch electronic ballast with active power factor correction is presented in this study for CFL applications. Unlike other single-switch ballast circuits, the presented integrated dual-boost converter circuit can produce a symmetric bipolar square-wave voltage, thus generating a near-pure high-frequency sinusoidal voltage on the lamp, which is beneficial to the CFL lifetime. Moreover, its soft-switching variant can achieve the ZVZC turn-on and ZV turn-off for the MOSFET to improve the conversion efficiency. Detailed operating principles and circuit analysis of the proposed circuit have been provided in this study. Simulation and experimental results on a prototype of a 15 W CFL validate the theoretical analysis and highlight the merits of the presented work.