Design Of Photoelectric Integrated LED Module With Overvoltage Protection And Junction Temperature Control

In the paper,photoelectric integration LED module was taken as the research object,a kind of photoelectric integration LED module was put forward which can steady the current when input voltage rose and control junction temperature when working temperature rose,the research was carried from driver,heat dissipation,junction temperature controling and testing.The main work and conclusions are as follows:Firstly,the equivalent model of light source in the work area has been established according to its volt-ampere characteristic curve.The resistance-temperature relationship of PTC has been measured.The working principle and defects of linear diver has been analysied so as to clear the improve direction of the driver.Secondly,the mechanism that use voltage difference to regulate LED current in the driver has been proposed against the defects of traditional linear driver.The extension structure,circuit schematic and parameters of the driver have been designed and optimized.The overvoltage limiting function has been proved to be realized by comparing with the traditional linear driver,and the average LED current changed less than 5% when input voltage was changed within AC220-265 V.Furthermore,the heat management of LED modules has been finished with the help of finite element thermal steady simulation,mainly include the optimization of the light source configuration,the optimization of the shell's sizes by orthogonal experiment.The design of PTC linking and controling the LED junction temperature has been completed by combining the result of thermal design and driver design.Finally,the module samples has been tested,including driver test,junction temperature test,junction temperature controlling effect test,the results show that: the total power of the module was 30.58 W,the power efficiency was 86.6%,the power factor was 0.910,the junction temperature of the light source was 78.6,when environment temperature changed witin 25-45,the highest junction temperature was 84.6,junctio n temperature protection has been realized.Based on the photoelectric integrated LED module,a floodlight has been designed whose luminous flux was 3329.41 lm,light effect was 108.77 lm/W.