A simplified thermal resistance network model for high power LED street lamp

Abstract

Light emitting diode (LED) street lamp heavily relies on successful thermal management, which strongly affects the optical extraction and the reliability/durability of the LED lamp. In this study, a thermal resistance network model was presented to estimate the maximum heat sink temperature of the street lamp, which could be utilized to further evaluate the thermal performance of the street lamp. Two high power LED street lamps, an 114 watts and an 80 watts LED street lamp were used to evaluate the present model. Their heat sink temperatures were calculated by the model, the results showed that the maximum heat sink temperature was about 61°C at the environment temperature of 25°C for the 114 watts LED street lamp. For the 80 watts LED street lamp, the maximum heat sink temperature was about 42.5°C at the environment temperature of 11°C. To prove the model feasibility, experimental investigations on the 114 watts and 80 watts LED street lamp were conducted. The results demonstrated that the heat sink temperature of the 114 watts LED street lamp remained to be stable at about 60°C after several hours’ lighting at the room temperature of 25°C. The heat sink temperature of the 80 watts LED street lamp remained to be stable at about 42°C at the room temperature of 11°C. Comparing the results achieved by the thermal resistance model with the experimental results, it was found that the proposed thermal resistance model could be used for temperature estimation and thermal evaluation for the high power street lamp.