A novel single-stage LED driver with coupled inductors and interleaved PFC

This paper proposes a novel single-stage light-emitting diode (LED) driver with coupled inductors and interleaved power-factor correction (PFC), suitable for streetlight applications. The presented LED driver integrates an interleaved boost PFC converter with coupled inductors and a half-bridge-type series-resonant converter cascaded with a full-bridge rectifier into a single-stage power-conversion circuit. Coupled inductors inside the interleaved boost PFC converter sub-circuit are designed to operate in discontinuous-conduction mode (DCM) for achieving input-current shaping, and the half-bridge-type series-resonant converter cascaded with a full-bridge rectifier is designed for obtaining zero-voltage switching (ZVS) on two power switches to reduce their switching losses. Analysis of operational modes and design equations for the presented LED driver are described and included. In addition, the proposed driver features high power factor, low total-harmonic distortion (THD) of input current and soft-switching. Finally, a prototype 165W-rated LED driver is developed and tested with a utility-line input voltage of 110V. Satisfactory outcomes from experimental results demonstrate the feasibility of the proposed circuit.