A novel single-stage high-power-factor LED street-lighting driver with coupled inductors

Abstract

This paper proposes a single-stage high-powerfactor LED driver with coupled inductors for street-lighting applications. The presented LED driver integrates a dual buck-boost power-factor-correction (PFC) AC-DC converter with coupled inductors and a half-bridge-type LLC DC-DC resonant converter into a single-stage conversion circuit topology. The coupled inductors inside the dual buck-boost converter sub-circuit are designed to be operated in discontinuous-conduction mode (DCM) for obtaining high power factor. The half-bridge-type LLC resonant converter is designed for achieving soft-switching on two power switches and output rectifier diodes in order to reduce their switching losses. The proposed driver features cost-effectiveness, low input current total-harmonic-distortion (THD<10%), high power factor (>0.99) and reduced components counts. Finally, a prototype driver for powering a 144W-rated LED lamp with an 110V utility-line input voltage is developed, and satisfying experimental results demonstrate the feasibility of the proposed LED circuit.