Research On High Power Factor LED Driver Power Based On Electroless Capacitors

Under the premise of advocating energy conservation and protecting the environment, with the unique advantages of high efficiency, environmental protection and energy saving, the development prospects of LED lighting are self-evident. It’s like a bright pearl. It not only illuminates the future direction of the illumination source, but also makes human lighting into a new "green lighting" era. LED lighting has incomparable advantages. However, due to the lack of technology and stagnation, the driving power of life issue is imminent, and capacitors are the primary factor affecting the life of the electrolytic. Generally, the life of electrolytic capacitor is not more than 5000 hours, but the life of LED is more than 40000 hours, their life are extremely mismatched. Therefore, to explore LED driver of non-electrolytic capacitors has important practical value and application value.In the dissertation, the research background and significance of the subject are described in detail, and the characteristics of LED are also introduced. In practical applications, the requirements of LED power supply are also presented. At the same time, the basic principles of switching power supply, topological structure, and power factor correction technology are also analysed deeply. To further improve the power of life, on the basis of a conventional capacitor filter, the series inductance is added for reducing the capacitance and avoiding the use of electrolytic capacitors. Thus, it can be used to replace electrolytic capacitors with other capacitances. Based on the above theoretical foundation, LNK417 is the main chip, and a LED driver using for industrial lighting is produced. In this issue, the constant current control and power factor correction technology are combined. This method eliminates the need for switching stage, and avoids the use of large electrolytic capacitors. In addition, the power is committed to improving its reliability, and it is important to assess reliability. After the completion of the optimization design of the power, reliability evaluation is required. Reliability evaluation results show that, the life of the use of LC filter circuit, which extend the life of power supply and improve the reliability of the circuit, is 1.6 times that of conventional electrolytic capacitor filter circuit. Finally, for the electromagnetic compatibility, reasonable solutions are proposed. In order to verify the reasonableness of scenarios, important parameters need to be simulated tests.In the dissertation, a LED driver is produced. Its input voltage is universal input voltage 90V-265V. and output signal is 30V/500mA. In the actual process, through numerous debugging, eventually, the prototype of meeting the design requirements was made, the efficiency of prototype is up to 90%. and the PF value is not less than 0.9. Test results show that this power supply has high efficiency, high PF. long life and so on, and it has a high application value.