Voltage distortion in LED street lighting installations

Abstract

The paper considers two power quality issues: voltage distortion and voltage drop along the pole lines of different LED street (road) lighting installations. The research includes three parts: (1) development of a novel model and the corresponding software for calculating voltage harmonics in the three-phase LED street lighting installations, where the load is nonsymmetrical and nonlinear. The model is based on the application of symmetrical components and the impedance per phase model. (2) Experiments on two sections of a pilot street lighting installation, one with 6 poles with neutral white and the other with 5 poles with warm white LED luminaires (the former were with conventional, and the latter with improved drivers regarding harmonic emissions). Their results were used to define harmonic characteristics of the LED luminaires and validate the model. (3) The developed software was applied to four typical street (road) lighting installations, two with a single-sided and two with a central pole layout. The major outcome was the determination of the maximum permissible number of the LED luminaires which can be connected to the feeding cable without exceeding any of the limits related to voltage drop, total voltage harmonic distortion and individual voltage harmonics in either the full or reduced street lighting regimes.