High-Efficient High-Power-Factor Off-Line LED Driver based on Integrated Buck and Boost Converter

Abstract

In this paper, an integrated buck and boost converter (IBBC) is proposed as a high power factor (PF), low total harmonic distortion (THD) light-emitting diode (LED) driver. The IBBC is a two-stage driver that features just one controlled switch, which leads to high PF and low THD operation insuring good efficiency, and size and cost reduction. Moreover, the switch handles less current as it conducts the higher of the buck or boost converter, but not the addition of both. In this paper, the IBBC is analyzed, and a design methodology is proposed. In addition, the paper presents a prototype of the proposed converter supplying an LED luminaire of 46 V/ 0.575 A. The prototype shows a high PF equal to 0.981, very small THD of 14%, output current ripple of 6 %, and efficiency of 90.5 %.