|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|147097||2017||12 صفحه PDF||سفارش دهید||5318 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Optik - International Journal for Light and Electron Optics, Volume 149, November 2017, Pages 69-80
In order to quickly acquire the lifetime and reliability prediction for LED lighting products, the method of step-down accelerated aging test based on Nelson models is experimentally studied in this paper. Ten Lide lamps and ten Philips lamps are used in the accelerated aging tests, with humidity less than 50%. The ambient temperatures are 90Â Â°C and 70Â Â°C for Lide lamps, and are 90Â Â°C and 80Â Â°C for Philips lamps. The models, the equal cumulative amount of degradation and the equal cumulative failure probability, are used to obtain the equivalent test time from one stress to another. The maximum likelihood function method is used to obtain two unknown parameters of Weibull distribution at the accelerated ambient temperatures. Then the distribution of the failure probability of LED lamp at ambient temperature of 25Â Â°C is obtained by Arrhenius model. The lifetime tests recommended by Energy Star standard are conducted to verify the accuracy of the models. It is shown that the model of equal cumulative amount of degradation is with a smaller error of lifetime estimation which is respectively 1.74%, 2.41% and 6.57% at the failure probability of 63.2%, 10% and 1% for Lide lamps, and is respectively 8.19%, 1.06% and 5.89% for Philips lamps in this research. The total accelerated aging time about 1000Â h is achieved in this experiment, which is quite satisfactory for a quick lifetime prediction of LED lamps recently.