Research on LED temperature characteristic and thermal analysis at low temperatures

Guo, Yu; Pan, Kailin; Guotao, Ren; Chen, Shujing; Yuan, Fei

doi:10.1109/icept-hdp.2012.6474870

Cited by 8 publications

(4 citation statements)

References 6 publications

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“…where: P H -heat power, η o -optical efficiency and P e -electrical power. Currently, in many references the optical efficiency of LED sources η o is declared to be at the level of 15-35% [29][30][31][32][33][34]; one can, however, encounter certain references where the efficiency η o is a bit higher, reaching up to 45%, depending on the LED source model and I F forward current used [35].…”

Section: Figurementioning

confidence: 99%

Thermal Analysis of the Factors Influencing Junction Temperature of LED Panel Sources

et al. 2019

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Limiting junction temperature T j and maintaining its low value is crucial for the lifetime and reliability of semi-conductive light sources. Obtaining the lowest possible temperature of T j is especially important in the case of LED panels, where in a short distance there are many light sources installed, between which there occurs mutual thermal coupling. The article presents results of simulation studies connected with the influence of construction and ambient factors that influence the value of junction temperature of exemplary LED panel sources. The influence of radiator's construction, printed circuit boards, as well as the influence of ambient factors, such as ambient temperature T a and air flow velocity v were subjected to the analysis. Numerical calculations were done in the FloEFD software of the Mentor Graphics company, which is based on computational fluid dynamics (CFD). For construction of the LED thermal panel model the optical efficiency η o and real thermal resistance Rth j-c were determined in a laboratory for the applied light sources.

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Section: Figurementioning

confidence: 99%

Thermal Analysis of the Factors Influencing Junction Temperature of LED Panel Sources

et al. 2019

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“…However, it is inevitable that it, like traditional light sources, has serious heat dissipation problems. The electron hole recombination in the PN junction of LED lights generates light and heat, and about 70% of the electric energy is converted into heat due to non radiative recombination, and the rest is converted into light, indicating that the Solar-cell efficiency of LED is only about 20%~30% [4][5] . Low Solar-cell efficiency not only reduces the luminous flux of LED, but also directly increases the junction temperature and even significantly reduces the life of LED [6] .…”

Section: Introductionmentioning

confidence: 99%

Research on LED junction temperature measurement method based on infrared thermal imaging

Zhao,

Zhang,

Wang

et al. 2024

Ninth International Symposium on Sensors, Mechatronics, and Automation System (ISSMAS 2023)

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This article analyzes the phenomenon of LED junction temperature changing with the circuit and environment, and proposes an improved measurement of LED junction temperature based on infrared thermal imaging method. By fitting the curve between heat transfer parameters and LED chip and packaging parameters, an LED experimental model is constructed, and junction temperature detection experiments and theoretical simulations are carried out. The results indicate that compared to traditional infrared thermal imaging methods, this method is more convenient and intuitive, and can quickly measure LED junction temperature. Finally, this article compares the LED junction temperature detection results under different experimental conditions to verify the universality of this method.

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“…Only a small part of the power supplied to the LED sources is converted into luminous flux Φ, while the remaining part is lost in the form of heat [14,15]. According to most scientific publications, the optical efficiency of LED sources is 30%, which means that 70% of the power is heat loss [16][17][18][19][20][21]. In a small number of publications, the research results indicate that, for the latest LED sources, the above value of optical efficiency may be higher [22,23].…”

Section: Introductionmentioning

confidence: 99%

Modeling of Selected Lighting Parameters of LED Panel

et al. 2020

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Semiconductor light sources are currently the fastest growing and most energy efficient group of light sources used in lighting technology. Their lighting parameters, such as luminous flux, correlated color temperature and color rendering index depend on the value of the forward current, as well as the temperature of the junction. LED source manufacturers usually specify, in data sheets, the effect of junction temperature and forward current on the luminous flux for individual light sources. The difficulty, however, is the correct determination of temperature and then lighting parameters, by simulation methods for multi-source lighting systems. Determining the junction temperature which affects lighting parameters is particulary important in the case of LED panels and luminaires, where thermally coupled LED sources shaping the output lighting parameters are in close proximity to each other. Additionally, other factors influencing the temperature distribution of sources, such as the design and geometry of the cooling system, the design of the printed circuit and thermal interface material used, should be considered. The article is a continuation of the publication in this journal where the influence of factors influencing the temperature distribution of the LED panel is presented. The purpose of the research in this article was to confirm the possibility of using CFD (Computational Fluid Dynamics) software, as well as to determine the accuracy of the results obtained in the temperature analysis of the multi-source LED panel, and in determining the output lighting parameters of the LED panel based on it. In this article, based on previously published research, a LED panel model with a cooling system was made, and then the CFD software determined the junction temperature of all light sources. The determined temperature of the LED sources constituted the basis for determining the output lighting parameters of the panel: luminous flux, color temperature and color rendering index. The simulation results were verified by real measurements on the constructed LED panel prototype. The LED panel temperature difference between the simulation results and the real results on the prototype did not exceed 5%. Moreover, the error of lighting parameters between the simulation results obtained and the results on the LED panel prototype in the worst case was 4.36%, which proves the validity and accuracy of simulation studies.

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Research on LED temperature characteristic and thermal analysis at low temperatures

Cited by 8 publications

References 6 publications

Thermal Analysis of the Factors Influencing Junction Temperature of LED Panel Sources

Thermal Analysis of the Factors Influencing Junction Temperature of LED Panel Sources

Research on LED junction temperature measurement method based on infrared thermal imaging

Modeling of Selected Lighting Parameters of LED Panel

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