Research Of Multi-objective Tolerance Design On Led Street Lamp Driver

As a new generation of green light source, LED has many advantages of safe, energy saving, long life cycle and so on, which make it used in many regions, just like signal lighting, automobile lighting, architecture lighting, and especially in road lighting it has the wider foreground. But the SMPS(switching mode power suply), which is used to drive LED lamp, restricts the promotion of LED lighting equipments because it has the problems of bad stability of output current, low reliability and shorte life, which mismatch the LED lamp. So reliability design on driver for LED is of both theoretical and practical value.As an important reliability design approach, traditional tolerance design has its own limitation. The reason lies in its paying more attention on the system's output characteristics. Based on the existing tolerance design, MOTD (multi-objective tolerance design) method is proposed in this paper, which not only cares the system's output characteristics but also takes every component in consideration. So it could guarantee consistency and stability of the output, at the same time improve the system's reliability.This paper analyzed the LED street lamp driver by building its model. The stress factors, affecting the component's life, were obtained via the degradation model and treated as the targets of MOTD with the system's output characteristics. Building the driver's simulation model by PSpice avoids the problems, just like the unsafety, time consuming, hard measuring and so on, brought by debugging the circuits, ensures the well-off application of MOTD in LED street lamp driver.This paper did the reliability analysis to the LED street lamp driver using reliability modeling and prediction, failure mode and effect analysis and fault tree analysis, and found the key components to the driver'reliability and life, which established the basis for MOTD to the LED lamp driver.This paper implemented the MOTD method to the LED lamp driver and tested the driver by both simulation and experiment. The results indicated that the driver after design had stable and consistent output current, and that the key components' failure rates fell obviously. So it greatly improved the reliability and increased the life of the diver by using the MOTD approach.