On the reduction of the third-order harmonic losses in low–voltage power cables used for feeding large LED and CFL lighting loads

D Milardovich,L Prevosto,M Á Lara,N J Milardovich

doi:10.7716/aem.v6i3.542

Abstract

An experimental investigation of diversity factors of CFL (compact fluorescent lamps) in combination with LED (light emitting diode) lamps is presented in this paper. Attention was paid to the reduction of low–order harmonic currents, especially the third one; which is mainly responsible for the strong increase in power losses in the neutral conductor of low–voltage installations. The harmonic currents drawn by several LED and CFL lamps with nominal powers < 25 W were first measured to investigate the electrical characteristics of individual lamps. In addition, a series of experiments was conducted in which LED lamps were powered between lines through small autotransformers thus avoiding the use of the neutral conductor. The results showed in both cases a sensible reduction of the harmonic current of third order and therefore a marked reduction of the power losses associated with them.

Highlights

Due to global government policies, incandescent lamps were gradually replaced by compact fluorescent lamps (CFL), and the latter are being replaced by light emitting diodes (LED) [1,2,3], seeking a reduction in lighting costs and a lower impact on environment. LED technology usually shows greater efficiency compared to older lighting technologies, it usually introduces harmonic currents of relatively large amplitude, especially of third order, in the electrical networks destined to these applications [4,5]
Attention was paid to the reduction of low–order harmonics, especially the third one; which is mainly responsible for the strong increase in power losses in the neutral conductor of the low–voltage installations [4]
An experimental investigation of diversity factors for LED in combination with CFL and LED lamps with nominal powers < 25 W was presented in this paper

Summary

Introduction

Due to global government policies, incandescent lamps were gradually replaced by compact fluorescent lamps (CFL), and the latter are being replaced by light emitting diodes (LED) [1,2,3], seeking a reduction in lighting costs and a lower impact on environment. LED technology usually shows greater efficiency compared to older lighting technologies, it usually introduces harmonic currents of relatively large amplitude, especially of third order, in the electrical networks destined to these applications [4,5]. In order to better show the contribution of the proposed solution, the measured spectrum of the harmonic currents (expressed in per–unit of the fundamental harmonic current), both in one phase and in the neutral conductor of a four–core cable, feeding balanced single–phase loads formed by selected LED–LED combination is shown in Fig. 7 and 8, respectively.

Results

Conclusion