Research And Design Of LED Street Lamp Driver And Illumination Sensing Control Technology

LED street lamp is a new kind of urban lighting source with the advantages of greenenergy, fast starting, easy dimming, etc. There are many problems in the design of LED streetlighting system. The first problem is the driving power supply of low efficiency, low powerfactor and short life. The driving power directly affects the performance and life of LED streetlamps. Another problem is about the control method. A LED street lamp often uses simpledirect lighting method without intelligent control based on detecting the street lightingconditions or uneven luminous in real time. This paper will study these two problems- theLED street lamp driving power and control methods, design the corresponding driving powerand illumination sensing circuit, and put forward the corresponding intelligent controltechnology to strengthen the application of LED street lighting.Based on studying the light-emitting mechanism, electrical, thermal and opticalproperties, the driving power requirements for LED street lamp applications, this paperdesigned a 150 W LED driving power with high power factor and high efficiency. The firststage was based on the PFS708 EG power factor correcting circuit, the second stage was basedon LCS702 HG half-bridge LLC resonant circuit. The experimental data showed that thepower factor was up to 99%, efficiency up to 93% in the case of driving full load. The pulsewidth modulation(PWM) dimming method was selected which proved that the circuit couldbe dimming normally, and meet the system requirements.To solve the problem of LED controlling method, this paper designed the illuminationsensing circuit first, and then designed a fuzzy controller based on the illumination sensing.Finally simulation results with MATLAB showed that fuzzy control technology for LEDstreet lamp was feasible to achieve further energy saving.