Test procedure of indoor lighting LED luminaires based on step-stress accelerated degradation test

LED luminaire system has lots of failure modes. And the interaction among various failure mechanisms is extremely complex. There is a great obstacle existed in assessing the system reliability of LED luminaires. Therefore, in order to quickly and accurately assess the reliability of LED luminaires products, a test procedure for indoor lighting LED luminaires is initially proposed in this study. Firstly, according to the characteristics of LED luminaires, the sample size and corresponding confidence level are selected. Secondly, in order to overcome the influence of LED luminaire weaknesses on reliability assessment, LED luminaire is decomposed into several independent subsystems, and then step stress accelerated tests are conducted on the LED light source subsystem only, which is placed in a thermal chamber and connected to other subsystems outside the aging furnace. The test stress level, the step size, the measurement method and failure criteria are determined while considering that sample has a sufficient amount of degradation under each stress level. Finally, the reliability of LED luminaires is achieved after carrying out the degradation modeling, the distribution analysis and the reliability function calculation. The proposed procedure is further expected to be one of technical specifications on assessing the reliability of LED luminaire system in the future.