Study of Degradation of LED Lighting Devices and Reliability of Their Power Supplies under Long-Term Operation in Real Conditions

The results of reliability tests of a number of LED lighting devices under real-world conditions have established corrosion processes, solder and LED coating degradation, and their I–V curves after long usage. Such shortcomings are caused both by construction defects (housing leakiness), and by the operation of LED lighting devices in irregular humidity and temperature conditions. It should be noted that despite the presence of degradation signs of LED lighting devices, their electrical and colorimetric parameters, and the characteristics of power supplies were valid. However, in long-term operation of LED lighting devices LEDs and matrices are most likely to fail. As a result of run-to-failure tests of the power supply of LED lighting devices in real operation conditions, the main cause of failure are voltage surges and dips, frequent overloading, and temperature regimes mismatch. For power supplies of LED devices, power circuits or drivers are most likely to fail. To increase the durability of power supplies of LED lighting devices, overvoltage protection, and non-optimal operation mode indication should be implemented.