Design And Implementation Of A High-efficiency Multi-channel LED Driver Without Electrolytic Capacitors

Light Emitting Diode(LED),as a new type of current lighting product,is gradually replacing others with its high-efficiency energy conversion rate,excellent luminous performance,long working life,energy saving,environmental protection,economy and safety,and diverse luminous colors.Lighting equipment is widely used in light source fields such as transportation and medical treatment,agricultural production,screen display,street lamp landscape lighting,etc.However,due to the complex and diverse circuit components of LED products,it has the disadvantages of difficult integration structure,short driver life,and low brightness of a single LED light source.Lighting needs,so this article takes high luminous efficiency,long life,and investment savings as the research goals,and proposes a new type of LED driver topology to avoid shortcomings at this stage.The specific research content is as follows:Multi-loop output LED products will cause unbalanced current output and stroboscopic problems.At the same time,frequency conversion control will directly lead to larger reactive power cycles and make the design of electromagnetic interference(EMI)loops more complicated.In addition,in the case of load changes,the constant frequency switching operation cannot realize the soft switching technology.A multi-channel LED dimming circuit based on variable inductor(V-Ind)was introduced in this paper,to obtain the balanced LED drive current required.It completes constant frequency operation and Zerovoltage switch(ZVS).The overall efficiency of LED products is improved.A half-bridge circuit configuration of the proposed structure superimposed will increase the number of outputs and share the resonant inductor,thereby increasing the power density and simplifying the unit LED dimming.This article introduces the working principle of the circuit.It uses the 8-channel output to build an experimental prototype to verify the LED driver's feasibility.Also,LED drive power is required to compensate for differences in the pulsating electrolytic capacitor,thereby limiting the LED products' life.The existence of full-bridge rectifier circuit and multi-stage conversion hinders the further improvement of its power density.In order to solve the existing problems,this paper proposes a single-stage dual-port network of bridgeless LED drivers with power decoupling capability and a shared mode to reduce the use of equipment and achieve higher power density.One port dedicates to implementing the power supply decoupling function.The film capacitor can be used instead of long-life electrolytic capacitors to reduce the decoupling capacitor's capacitance.This paper examined the working principle,design considerations,and performance comparisons.finally,a simulation and experimental prototype builts to verify all of the proposed LED drivers' superiority.