Research And Design On The High-power Led Driver Based On Peak Current Controlled Method

Light-emitting diode (LED) is a solid light-emitting device. Because of its green, luminous efficiency, long life, low power consumption, resistance to vibration and so on, it has been widely used in all aspects of daily life, and is considered the 4th generation illumination light source. It has a great trend to replace traditional light sources. But all the advantages of the high-power LED need a reasonable premise-driver, so the LED driver circuit research and design is very important and necessary.This paper begins with a brief introduction of the light-emitting characteristics, volt-ampere characteristics, research status, and driver programs of the LED. Based on the actual appliance request, a high power factor, with accurate drive current high-power LED driver circuit has proposed in this paper.LED drive circuit of this paper can be divided into two parts. The first part is the PFC circuit, using the Boost-PFC circuit controlled by TOPSwitch. This circuit can achieve high power factor, reducing input current and voltage harmonics and distortion, and can post constant voltage into the final stage. The detailed analysis of the PFC circuit topology and operating principle are proposed in the paper, so as the establishment of a small-signal model. At last, time-domain and frequency domain simulation of the former Boost-PFC circuit are given in the paper. The dynamics of the system performance and steady-state performance has been verified.The second part of the circuit level is LED driver circuit controlled in the peak current mode. Constant current drive and a stable dimming of high-power LED can be achieved in the circuit. The article described the topological structure and working principle of the post-stage LED driver circuit in detail and the post-stage small-signal model of the main circuit by using state-space averaging method is established. At the same time, the dynamic performance of the system are analyzed, and finally through the time domain and frequency-domain simulation, the control performance and stability of the LED drive circuit are verified.Paper concluded with a test validation, using the above-mentioned high-power LED driver circuit to drive the thirty 1W High Power LED series circuit. The detailed indicators and the requirements of the circuit component parameters are given in this article. Test results validate the correctness of theoretical research and simulation results.