The Research And Design Of Single-stage LED Driver Based On Resonant Soft-switching

The fourth-generation light source LED has the characteristics of high luminous efficiency,long life,and zero pollution,and it has received more and more attention in the lighting field.High-efficiency,high-quality drive power is crucial to the development and popularity of LED lighting technology.In recent years,research on LED drive power has become a hot topic.The traditional AC power supply LED driver usually consists of two levels,the former stage to achieve power factor correction,the latter stage to achieve constant voltage and constant current output;and single-stage LED drive power has a simple structure,simple control,low cost and high efficiency,which receives a lot of attention.For this reason,this article mainly focuses on single-stage LED drive power.First of all,based on the classical flyback converter,a new type of fully softswitching DC/DC converter combined with the active clamping structure and quasimultiplier unit is developed,which has the characteristics of high efficiency and high power density.The working principle and performance characteristics were analyzed.The voltage gain,soft-switching conditions and the current-voltage stresses on the components were deduced.Finally,a 160 W experimental prototype was developed.Secondly,on the basis of the above new DC/DC converter,a novel single-stage LED driver circuit is deduced by combining a Boost converter and a constant current unit.It has the characteristics of power factor correction,multi-channel constant current output and the characteristic of soft switch.The various operating modalities and working principles are detailedly analyzed,and the process of the main circuit parameter is developed,supplemented by software simulation to verify.Finally,on the basis of the above studies,an experimental study is conducted on a single-stage LED driver.The auxiliary power supply,output protection,sampling and driving circuit of the drive power supply are designed.In addition,the digital PID is elaborated and designed in detail,and the design of various modules of the experimental prototype to be built is basically completed.Finally,an experimental prototype with threechannel constant current output under the input of industrial frequency AC is built.The experimental results verify the correctness and validity of theoretical analysis and design.