Research Of Degradation Parameters Monitoring And Lifetime Prognosis Method For LED Drivers

According to statistical data, LED drivers are of great failure rate whichseverely influences the reliability of lighting devices. For products of lengthylifetime the traditional reliability research method which is established based on thestatistical analysis of testing samples’ failure data processes unelectable drawbacks.Therefore, in this paper by monitoring the degradation parameters of LED driverand modeling its degradation process and eventually obtaining its degradationprinciples, the lifetime prediction method for LED drivers on basis of degradation ispresented, which has theoretical significance and practical value.In combination of the structure and principle of this type of driver, the failuremechanism and degradation models of critical components in LED drivers arediscussed in this paper, which highlights the failure mechanism and degradationmodels of the electrolytic capacitors, MOSFET and power diodes. By the means ofEDA simulating technique, the degradation impact on the power supply is studied.To achieve the research on the degradation of LED drivers, a performancedegradation parameters monitoring and lifetime prediction system for LED driversis designed, providing the experimental platform for the degradation experiments ofpower supply.The degradation experiments under various temperature stresses are exerted forthe LED driver. Making use of the designed experimental system, the performanceparameters of power supply and critical components are monitored. The de-noising method of SVD-wavelet is studied based on the theory of wavelet theoryand the experimental data preprocessing is carried out for all of the experimentaldata.By adopting the Wiener process to the degradation equation, a revised Wienerdegradation process with parameters’ drift is obtained for LED drivers, and thereliability assessment for them are carried out. As for the critical components inLED drivers, the degradation for electrolytic capacitors is studied in this paper. Byextracting the degradation parameters of capacitors, the degradation law of them isobtained and lifetime prediction for them is also implemented. The outcomeindicates that the prediction by the parameter of ESR can better reflect the realconditions.