Research On High Power LED Driver With LLC Resonant Converter

Along with the advance of human society,as well as the continuous improvement of energy demand,the new energy development has become the main issues in the new century.One of it,LED is high efficiency,long working life and the green environmentally friendly and it has been widely used in various fields of life.With the semiconductor technology rapid growth,high-power LED lighting has become a hot spot in recent years.Besides,LED dimming technology not only beautify the lighting effects,further improve energy efficiency.Under this background,the paper studies the characteristics of high power LED dimming lighting and the driver with high efficiency,stable and wide dimming range.The main topologies of the LED driver are analyzed and compared in this paper,and the LLC resonant converter suitable for high power LED driver is discussed emphatically.Further,I studied the relevant technologies at home and abroad and summarized their own inherent merits and drawbacks for the wide dimming lighting.Based on this,a simple variable resonant inductor(VRI)optimal control method is proposed,and an in-depth analysis is carried out.This paper learned the specific impact of VRI in LLC converter.It optimized and designed for wide range dimming combined with the laboratory 110 W LED street lamp.It mainly includes two parts: First,the optimal design of traditional LLC resonant converter for high-power LED dimming lighting;Second,the optimization analysis and design of LLC resonant converter with VRI.The main research contents include basic operation principle analysis of the LLC resonant converter,the influence of distributed capacitance in practical circuit,the main working principle and optimization design of the VRI,etc.In addition,the simulation circuit was designed with Psim software.It combined with the theoretical analysis and derivation in the previous chapters,which verified the experiments.The proposed prototypes were designed and compared with the results,which verifies the correctness of previous theoretical deduction,and the VRI technology is well applied to the high-power LED wide dimming applications.