Assessment of harmonic pollution by LED lamps in power systems

Abstract

Modern energy-efficient LED lamps draw non-sinusoidal currents from the grid. The harmonic distortion level varies with the quality of lamp's non-linear driver circuit. This paper studies the problem of system-wide harmonic impact with consideration to both the variation in lighting load and difference in quality of LED lamps available in the market. An electrical classification model is proposed for LED lamps based on their harmonic spectrum and an analysis is carried out to quantify the distortion and losses possible in power system if such lamps are to be installed. Extending prior work in this area, we use advanced harmonic analysis techniques and conduct evaluation with voltage-dependent harmonic current model for LED driver. We built a harmonic analysis tool using Gauss-Seidel Method to carry out our evaluations on IEEE-30 test bus system. We report our results using IEEE standard 1459 which provides definitions of power quantities under non-sinusoidal conditions. Evaluations show that poor quality LED lamps can cause significant distortion in a power system and good quality LED lamps introduce significantly lower distortion while providing high economic and environmental benefits.