Research On Illumination Systems Used For LED Energy-saving Road Lighting And Illuminance Distribution

This thesis is the discussion and research about the design and illuminance distribution of the illumination system of LED sources for road lighting. With the help of opto-mechanical simulation software—LightTools, a source of LED arrays is modeled. On the basis of the modeling results, an optical element is introduced to improve the illuminance distribution of the LED arrays.Because of their advantages, LED sources are more and more widely used. At present, illuminant quality of LED sources for road lighting on the market isn't good enough. The paper is to design a simple-structured and easy-handled optical system to improve its quality.The paper introduces the optical properties of the sources, the index and national standards for road lighting and summarizes the methods of illuminance design with and without softwares. By comparing the illuminance distribution charts generated by the professional software—LightTools, the paper analyses the illuminance properties of the different nonimaging optical elements applied to the LED lighting system. Based on the principles of the Fresnel lenses, a scatter element with the characteristics of the Fresnel lenses'microstructures is proposed and by multiple times of simulating and by comparing the results, a sound optical system is presented to increase the uniformity of the illuminance distribution on the road.According to the design, an element is processed, and a large amount of experiment is carried out to verify the effectiveness of the optical device. The experimental results show that the scatter element designed can improve the optical properties of the source and increase the uniformity of the illuminance on the road's surface. And in order to further improve the properties, reflectors are applied to the LED arrays source. The results show reflectors can increase the light utilization efficiency and can also increase the uniformity of illuminance. To conclude, the optical system which combines the scatter elements with the reflectors can further more improve the source's optical properties.