Boost型无频闪谐振降压式LED驱动电源分析与设计

Analysis and Design of Flicker-free Resonant Step-down LED Driver Based on Boost Topology

传统的二次型Boost功率因数校正变换器只能实现升压输出,在一定程度上限制了其在LED驱动电源中的应用。基于二次型Boost变换器提出了一种Boost型无频闪谐振降压式LED驱动电源,并分析了其工作原理及特性。该LED驱动电源利用一个有源开关管将二次型Boost变换器与一个谐振网络进行整合,可实现低电流纹波和降压变换输出。最后,搭建了一台84 W的实验样机,最高效率达到92.88%,验证了所提方法的正确性及可行性。

The conventional quadratic Boost power factor correction(PFC) converter can only achieve step-up voltage conversion, which limits its application in LED drivers to some extent. In this paper, a flicker-free resonant stepdown LED driver based on a quadratic Boost converter is proposed,and its working principles and characteristics are analyzed. This LED driver combines the quadratic Boost converter and a resonant network by means of an active switch.Similar to the conventional quadratic Boost converter, the proposed LED driver can achieve a high efficiency and a high power factor. In addition, it can achieve low current ripple output and step-down voltage conversion. Finally, an 84 W prototype with a peak efficiency of 92.88% was built, and experimental results verifiedthe correctness and feasibility of theoretical analysis.