The study of natural exposure testing for LED lighting system

Light emitting diode (LED) lighting is the most promising energy saving solution for future lighting application. For some LED applications, such as the building or bridge lighting application, the corresponding LED lighting system will be expected to be functional as long as the objects stand. Therefore it is necessary to obtain the degradation regularity of LED lighting systems and predict when failure is likely to occur. In this paper, the LED lighting system is defined as LED lamp (composed of a fixed number of LED strings and LED electrical driver). In order to research the degradation regularity of LED lighting systems in the field, natural exposure tests for LED lamps at Xisha and Guangzhou were performed. The key performance parameters including illuminance and color temperature were measured intermittently. Based on the parameter measurement, the performance degradation regularity of LED lamps at different locations was contrastively analyzed. The difference of temperature and humidity between Xisha and Guangzhou was also investigated to reveal the reason of diversity of performance degradation regularity at different location. Finally, data driven approach was used to assess the reliability and predict the remaining useful lifetime of LED lighting systems based the test data during the sustaining natural exposure test. The early warning of degradation and failure of LED lamps can be given according to the RUL prediction.