Ressearch On LED Lighting Driver And Intelligent Control System

With the improvement of living standard,people have more and more high requirements of lighting,they begin to pursue more efficient and intelligent lighting control mode,and intelligent lighting system can meet the diversified requirements of lighting.As the fourth generation of lighting source,LED has some advantages such as energy conservation and environmental protection,high brightness,long life and so on,and it has been widely used in road lighting,tunnel lighting and other lighting applications.So researching LED intelligent lighting control system has important significance and application prospects.The paper first introduces the research status and design requirements of the LED driver topology and LED dimming technology,and analyzes the advantages and disadvantages and applications of all kinds of LED driver topologies.Then introducing the mechanism,harm and suppression measures of low frequency ripple of single stage LED driver circuit.The paper puts single stage fly-back LED drive power supply as the research object,With the problem of single stage fly-back converter large output ripple at low frequency,the paper puts forward a new kind of circuit topology and control strategy to inhibition of single stage fly-back LED drive power supply output low frequency ripple.Circuit topology is consists of fly-back converter and secondary ripple suppression circuit,The main output of fly-back converter is in parallel with the output of ripple suppression circuit to provide a constant current power supply for the LED lights together.By adjusting the dynamic response of ripple suppression circuit,adjusting the duty ratio of ripple suppression circuit quickly to control the output current,making its output low frequency current ripple is equal in amplitude and opposite in direction with the main output low frequency current ripple of fly-back converter,the two cancel each other out,so that the low frequency ripple of LED current is suppressed.And analyzing the working principle and the ripple suppression mechanism of the circuit topology in detail and giving the design method of key parameters.And using the saber simulation software for simulation analysis to verify the effectiveness of the proposed circuit topology and control strategy.The paper also researches the hardware and software of DALI dimming control unit,designing the interface circuit between DALI bus and control unit to realize DALI level transformation.And writing the DALI dimming and control program,by changing the DALI dimming PWM signal into variable current reference signal to control the LED output current,so the DALI no stroboscopic light dimming is realized.Finally,setting up a 42W experimental prototype of low ripple LED drive power supply and intelligent control system,then testing the experimental prototype,the experimental results verify that the proposed scheme is feasible.