基于单级全桥PFC的低纹波LED驱动电源分析与研究

Research on the Low-ripple LED Driver Based on Single-stage Full-bridge Converter

提出了一种基于单级全桥PFC的低纹波LED驱动电路拓扑及其控制策略。利用钳位电路抑制了全桥PFC电路的母线电压尖峰,并将钳位电路与反激变换器结合构成纹波抑制电路,通过控制反激变换器输出电流纹波,使其与主电路电流纹波相位相反、幅值相近,达到削峰填谷的作用,实现了对输出侧低频电流纹波的抑制。详细分析了该电路拓扑的电路组成、工作原理及低频纹波抑制机理,并通过仿真软件搭建了仿真模型,验证了理论设计的可行性。

A low-ripple LED driver circuit topology based on single-stage full-bridge PFC and its control strategy is proposed. Using clamp circuit to suppress the bus voltage spike of the full-bridge PFC circuit,and combining the clamp circuit and the flyback converter to constitute a ripple suppression circuit,by controlling the output current of the flyback converter to make it phase opposite and amplitudes similar to the main circuit current,the ripple currents cancel each other out,and the low frequency current ripple at the output side is suppressed. The circuit composition,working principle and low frequency ripple suppression mechanism of this circuit are analyzed in detail. The simulation results verify the feasibility of the theoretical design.