Research Of Dimmable Flyback LED Driver

In the advocacy of "green" environmental protection, as a "green" and non-polluting way of lighting, it is gradually replacing the traditional way of lighting to be a new generation of lighting by the features of with long life, high luminous intensity and energy-efficient. While LED lighting has many advantages, but the most difference between the traditional lighting is that in order to work, LED lighting devices need to design a special LED drive power. With the popularity of LED lighting devices, more and more people began to join the ranks of the research and design LED drive power, LED drive power supply design directly affects the performance and lifetime of LED lighting equipment. This article is just based that, we combined with digital control theory to research the design of the LED driver power supply.This paper introduces the background and the significance of the research then it also introduces the present situation of the development of LED lighting, noted that the current LED lighting can’t be dimmed well, low precision, slow response and other issues. In this paper, we research the dimmable flyback LED driver that based on dsPIC30F2020 microcontroller. Article dimmable flyback LED driver power supply modules, including the dimming circuit, power factor correction circuit, the main circuit topology in-depth discussion and analysis, comparing the advantages and disadvantages between the different circuit design, and reasonable choice design. For the main circuit, through comparative analysis, choose the flyback converter as LED drive power main circuit, after analyzing the working principle of the flyback converter and on this basis, the use of small signal modeling method of flyback type circuit modeling to establish open-loop transfer function and pass through the open-loop function on the system characteristic analysis. Since the flyback converter with output not stable enough shortcomings, and LED lighting for LED drive power output is relatively high precision, this paper uses fuzzy adaptive PID control algorithm, the LED drive power output correction controls, in full after learning about the fuzzy immune PID algorithm, Matlab/Simulink simulation verification based on fuzzy immune PID control algorithm of the flyback LED driver power supply, and compared with the fuzzy PID algorithm. We came to the conclusion that the fuzzy immune PID control algorithm of the system performance is better than fuzzy PID.Finally, the article gives a flyback LED drive power of digital solutions in the digital process, the first from the parameter estimates, component selection and other aspects of the dsPIC30F2020 peripheral circuit, the switch driving circuit main circuit, the output current sampling circuit and other system-related hardware circuit was designed and completed the software part of the design dsPIC30F2020 microcontroller based on this basis.