LED luminaires have the characteristics of high reliability and long life-time and it is difficult to be evaluation of reliability. In order to assess the reliability of LED luminaires, Step Stress Accelerated Life Test (SSALT) method with temperature as its stress is used to test the LED luminaires. This method has shortened the test-time greatly. The test-time at 45°C is converted to a test-time at 85°C by using Nelson's law. Besides, Arrhenius model is selected to indicate the relationship between the average life of LED luminaires and temperature. Then, Maximum Likelihood Estimation (MLE) of LED luminaires life is established under lognormal distribution. Matlab software is applied to calculate the life of the samples and the reliability curve is acquired based on relevant reliability parameters.
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