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

Abstract

SUMMARYIn this paper, a single-stage integrated bridgeless AC/DC converter is proposed. As compared to its counterpart that is composed of totem-pole boost power factor correction (PFC) cascade fly-back DC/DC converter, the studied circuit has less components number while overcoming the limits of the totem-pole type. Thus, it is suitable to the low-power LED lighting applications. Furthermore, when both PFC inductors L b and magmatic inductance L m of the transformer TR1 operate at discontinuous current mode, the bus voltage v CB can be used to decouple the ac input and constant dc output power. Thus, the approach of increasing bus voltage ripple is employed to eliminate electrolytic capacitors and obtain long operation lifetime. Additionally, it is able to be compatible with our studied twin-bus configuration for increasing the overall efficiency. A 50-W hardware prototype has been designed, fabricated, and tested in the laboratory to verify the proposed converter validity.

Simplified electrical modelling of power LEDs for DC–DC converter analysis and simulation

“…Nowadays, power light emitting diodes (LEDs) are a good alternative for many lighting applications, because they have a high luminous efficiency and a long useful life. Therefore, several dc-dc converters have recently been proposed to feed power LEDs [1][2][3][4][5][6]. The simulations of these systems must be carried out with a reliable LED model so that the complete system behaviour can be investigated [7][8][9][10][11][12][13][14].…”

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.…”