| In recent years, with the improvement of the luminous efficiency, the application of high power LED in lighting is developed increasingly. As the guarantee of LED lighting, LED driver which uses the mains directly as the power sources of LED lighting is the general direction. And how to improve the efficiency of the driver and simplify the circuit and develop a suitful single stage PFC is concerned by all walks. By analyzing the PFC circuit based on Boost topology and LLC half bridge resonance circuit, a single stage AC - DC driver circuit without electrolytic capacitors is proposed in the paper. The main works are as follows:First of all, the advantages and disadvantages of the traditional two-stage AC - DC driving circuit are analysed, and proposed a single grade AC - DC driver circuit, which solves the disadvantages of many devices, high cost, low convertion efficiency and complicated control ciecuit in the two stage driver. In addition, the electrolytic capacitors typically used have placed limitation on the lifetime of LED lighting, and then a single stage AC - DC driver circuit without electrolytic capacitors is proposed in the paperThen, this paper details the working process and the principle of the proposed circuit, which provides theoretical basis for the design and calculation of the parameters. The Boost converter is operated at discontinuous conduction mode (DCM) to ensure a high power factor, and then LLC half bridge resonance circuit outputs pulse current to driver LED lighting.This paper designs a set of driving circuit, calculates the circuit parameters. And it is simulated using saber, the result shows the correctness of the theoretical analysis of the circuit.Finally, experiments are carried out to improve the feasibility of the circuit. The paper shows the process of the hardware design and the experiment results. |
