A Single-Stage LED Streetlight Driver with Soft-Switching and Interleaved PFC Features

Cheng Cheng,Chung Chung,Chang Chang

doi:10.3390/electronics8080911

Abstract

This paper presents a single-stage driver with soft-switching and interleaved power-factor correction (PFC) features suitable for light-emitting diode (LED) energy-saving streetlight applications. The proposed LED streetlight driver integrates an interleaved buck-boost PFC converter with coupled inductors and a half-bridge LLC resonant converter into a single-stage power-conversion circuit with reduced voltage stress on the DC-linked capacitor and power switches, and it is suitable for operating at high utility-line voltages. Furthermore, coupled inductors in the interleaved buck-boost PFC converter are operated in discontinuous-conduction mode (DCM) for accomplishing PFC, and the half-bridge LLC resonant converter features zero-voltage switching (ZVS) to reduce switching losses of power switches, and zero-current switching (ZCS) to decrease conduction losses of power diodes. Operational modes and design considerations for the proposed LED streetlight driver are introduced. Finally, a 144 W (36V/4A)-rated LED prototype driver is successfully developed and implemented for supplying a streetlight module and operating with a utility-line input voltage of 220 V. High power factor, low output-voltage ripple factor, low output-current ripple factor, and high efficiency are achieved in the proposed LED streetlight driver.

Highlights

With recent developments in green lighting and energy saving around the world, light-emitting diodes (LEDs) are characterized by their small size, long life, high brightness and environmental friendliness [1,2,3]
Traditional two-stage drivers for LED streetlight applications include AC–DC converters with power-factor correction (PFC) and DC–DC converters that provide rated voltage and current to the LED streetlight [14,15]
2vAC−rms sin(2π fAC t) Duty where LB represents the inductance of coupled inductors LB1, LB2, LB3 and LB4, and Duty is the duty cycle of the switches S1 and S2

Summary

Introduction

With recent developments in green lighting and energy saving around the world, light-emitting diodes (LEDs) are characterized by their small size, long life, high brightness and environmental friendliness [1,2,3]. The traditional source of illumination for streetlight applications is high-pressure mercury lamps, because of their low installation cost. High-pressure mercury lamps consume more energy and save less electricity. LED streetlights with energy-saving features have begun replacing traditional high-pressure mercury street lamps [12,13]. Traditional two-stage drivers for LED streetlight applications include AC–DC converters with power-factor correction (PFC) and DC–DC converters that provide rated voltage and current to the LED streetlight [14,15]. The literature presents some single-stage streetlight drivers that integrate an AC–DC converter with a DC–DC converter [16,17,18,19,20].

Methods

Results

Conclusion