Reliability evaluation of LED luminaires based on step-stress accelerated degradation test

Under the global trend of energy and emission reduction, light emitting diode (LED) has attracted more and more people´s attention due to its distinctive advantages of long lifetime, high reliability, low energy consumption, green environmental protection. However, in order to evaluate the reliability of LED luminaires, few or no failure time data could be obtained with the traditional accelerated method. In this paper, the step-temperature stress was selected and the step-stress accelerated degradation test (SSADT) was implemented for LED bulb firstly. Secondly, the reliability function, reliability curve and Mean Time to Failures (MTTF) of sample under normal stress level were calculated. Lastly, the predicted results were verified by mean value method and normal temperature test. In some extent, the reliability of LED lighting system can be effectively and rapidly evaluated by the SSADT method.