A single‐stage high power‐factor bridgeless AC‐LED driver for lighting applications

Abstract

An alternating‐current light‐emitting diode (AC‐LED) driver is implemented between the grid and lamp to eliminate the disadvantages of a directly grid‐tied AC‐LED lamp. In order to highlight the benefits of AC‐LED technology, a single‐stage converter with few components is adopted. A high power‐factor single‐stage bridgeless AC/AC converter is proposed with higher efficiency, greater power factor, less harmonics to pass IEC 61000‐3‐2 class C, and better regulation of output current. The brightness and flicker frequency issues caused by a low‐frequency sinusoidal input are surpassed by the implementation of a high‐frequency square‐wave output current. In addition, the characteristics of the proposed circuit are discussed and analyzed in order to design the AC‐LED driver. Finally, some simulation and experimental results are shown to verify this proposed scheme. Copyright © 2012 John Wiley & Sons, Ltd.

A single‐stage integrated bridgeless AC/DC converter for electrolytic capacitor‐less LED lighting applications

“…This lowfrequency diode bridge affects the efficiency improvement of AC-DC converters. In recent years, a number of bridgeless PFCs implementations and their variations involving boost-type circuit configuration have been proposed [12][13][14]. Thus, the conventional boost PFC circuit with low frequency diode rectified bridge can be replaced by bridgeless boost PFC circuits to improve the overall system efficiency.…”

“…Thus, the converter conduction losses can be reduced significantly and higher efficiency can be achieved, as well as cost savings. So far, a number of bridgeless AC-DC converter implementations and their variations involving boost-type have been presented [12][13][14]. These topologies can also be introduced into LED lighting field to boost the efficiency of LED lighting drivers.…”

A new bridgeless buck PFC rectifier

“…In the traditional active PFC rectifiers, the conduction loss of the line-frequency diodes is large. Therefore, in order to reduce the conduction loss caused by the line-frequency diodes, the bridgeless active PFC rectifiers are presented [29][30][31][32][33][34][35][36][37][38][39][40][41][42]. In this study, a new bridgeless buck PFC rectifier is presented, which is derived from the existing bridgeless buck PFC rectifier [40].…”

A long lifetime passive LED driver with power factor correction

“…Normally, a LED driver needs an ac-dc converter to convert the grid ac voltage to a low dc voltage. Although one can use an active power factor corrector (PFC) to achieve almost unity power factor easily [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], the added extra control circuit and the auxiliary power supply will not only increase the circuit complexity but also reduce the driver reliability. Although one can use an active power factor corrector (PFC) to achieve almost unity power factor easily [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], the added extra control circuit and the auxiliary power supply will not only increase the circuit complexity but also reduce the driver reliability.…”