This study describes a simulation for LED junction temperatures. LEDs will be new light sources for an automotive forward lighting system, for a headlamp. However, some technical problems that have to be addressed still exist for LED applications. Management of the maximum junction temperature on a tip under a phosphor is a fundamental challenge for controlling the LED. Although heatsinks serve as basic and reasonable devices for thermal diffusing, designing an appropriate heatsink generally requires experimentation. As a first step, the authors created a conduction model for the LED chip in order to apply a Fluid and Thermal Analysis (CFD). This allowed the prediction of the temperatures of the LED instead of actual testing. Subsequently the LED junction temperatures for three types of heatsinks were calculated and compared to estimated junction temperatures, based upon measured temperatures underneath the LED, because of the difficulty in measuring the junction temperature directly. Next, for the first generation of LED headlamps, the junction temperatures of the LED module, which includes a reflector, lens, heatsink, and LED were calculated. The result of the study shows that the LED junction temperature is predictable by using the Fluid and Thermal Analysis (CFD). The authors assumed that the submount layers were made of homogeneous material with uniform heat conductivity, as determined with the calculated and measured junction temperatures in the forced convection and natural convection models. The calculated results of the test sample with ten LED modules agree with the estimated temperatures, within a 11C range of error.
Prediction of LED junction temperatures with CFD for Headlamp Application
Prädiktion der LED-Sperrschichttemperaturen mittels numerischer Strömungsberechnungen für Scheinwerferanwendungen
2005
18 Seiten, 14 Bilder, 4 Tabellen, 3 Quellen
Aufsatz (Konferenz)
Englisch
Headlamp control apparatus, headlamp control system, headlamp system, and headlamp control method
Europäisches Patentamt | 2019
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