Investigation of photometric distribution of LED and HSPV for road lighting

Abstract

Lower energy consumption while preserving the required light brightness is one of the main purposes of changing from an HPSV lighting system to a LED lighting system for road lighting. The current practice of changing whole luminaires requires a huge capital cost. Although LED lamps have a high illumination rate, the lamp structure which is different from existing HPSV lamps may improve the light intensity. This condition causes changes to the original lighting design and may not meet the requirements. Therefore, the aim of this research is to study the photometric distribution of LED and HSPV lamps based on simulation analysis. Both lamps are simulated using Dialux Evo simulation software by varying pole distances according to MS 825:2007 and BS EN 13201-2: 2004 standards. The study involves average luminance, overall uniformity, longitudinal uniformity, and threshold increment parameters. The results show that the average luminance value of the LED replacement lamps is lower than HPSV lamps, with a reduction of 52%. However, there is a minimal change in the light distribution pattern with an overall uniformity difference of 2% and a longitudinal uniformity difference of 18%. The results will be useful for local authorities and manufacturers to study on usage of different LED lighting systems. Energy consumption can be reduced while preserving the required lighting level.