High Power Factor Led Driver Power

Light Emitting Diode (LED, for short) has the advantages of energy-saving, environmental protection, safety and long lifespan. It is a new generation of light source following filament lamp, fluorescent and high-pressure gas discharge lamp. The 21st century will be to enter a new era of the LED as the representative of solid light source. The development of LED lightning technology can't be separated from the high power factor, long lifespan and low-cost drive power source. For LED drive power, there are many problems existing in the market, such as low power factor, short lifespan and many other issues. Therefore, this subject has great theoretical significance and practical significance.This paper analyze many research literature, and systematically introduce the switching power supply power factor correction (PFC, for short) Through the comparion of Passive PFC, single-stage PFC and double-stage PFC techniques, we choose single-stage PFC technology as a solution for this design.This paper systematically discuss the circuit structure, control method and the operating mode of the single-stage PFC technique.We know clearly about the advantages and disadvantages of the operating mode of single-stage PFC mode, and their working principles and control methods. On this basis, this article use transfer mode (TM) controller chip L6562 to design a high power factor LED driver power supply in the end. This paper analyze the work principles and the control process of the chip in detail. We know clearly about the role of each pin and the input signal, and design the main circuit and the peripheral circuits of the L6562 in detail.Stability design is a hard part in power design. This paper establish the small signal model of Buck-Boost circuit and control loop model, using control theory to analyze the system open-loop transfer function and analyze the control loop theoretically with Nyquist stability criterion and Bode plot.At last, we simulate the circuits with Saber software, which is spoken highly of in the market and we get the desired simulation waveform. We test the experimental prototype, and get power factors and waveforms of input current and voltage under different conditions. The actual test results meet the design requirements.