Thermal analysis and optimization of high power led armature

Abstract

It is an effective way of energy conservation to use high power LED armature in street lighting. However, there exists some restrictions in front of the usage of that, like overheating of LED chips and high weight of armature case. Generally, aluminum heat sinks are attached to housing of the armature to get effective working of LED armature. In this study, a street type high power LED armature has been modeled numerically, transient thermal system has been analyzed and the results have been compared with experimental results in order to decrease the armature weigh and increase efficiency. Also, in experimental studies thermal camera and thermocouples have been used for thermal measurements. Finally, multi-objective optimization has been performed to decrease the armature weight, while keeping maximum temperature on armature between in safely working interval. Introduction Energy conservation and green energy topics gradually gains importance for government policies in order to protect the environment and reduce hazardous wastes. People also become conscious about this subject and prefer renewable energy and recyclable product. One of the most energy consumption area is outdoor and indoor illumination around the entire world. There are many research and development studies in order to decrease consumed energy in this area [1-4]. By improvements in solid-state lighting (SSL) systems, the development of high power LED is no doubt one of the best inventions at the scientific researches in two decades on lighting systems. Because of advantages of usage, such as: energy saving, high light quality, long product life and environmental friendly properties, high power LED are being widely used at various areas. For instance road and building lighting, household lighting, automotive lighting, traffic signal lights, and billboards are commonly usage areas of this technology. Considering the advantages and areas of usage high power LED or SSL systems which are more efficient and beneficial in many aspects compared to conventional lighting systems. Also it has been seen that high power LED luminaires for outdoor lighting are more efficient with respect to power input and light output (lumen/watt) compared with incandescent and florescent lamps. As an example in 110 W LED armature, product life with 60000 hours is nearly five times longer others and energy efficiency approach to 75% with 115 lumens per Watt (ln/W) [5]. Together with improved LED lighting technology and becoming prevalent of LED application save most of energy in illumination area. Several European countries are converting