Single-stage high power-factor bridgeless AC-LED driver for lighting applications

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 (PF) 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.