有源纹波补偿Buck型LED驱动电路及其小信号分析  

Small-signal analysis of the Buck circuit with active ripple compensation for LED

作　　者：唐治德[1] 谢小慧[1] 王官涛 张晓斌[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400044 [2]山东省电力公司滨州供电局,山东滨州256600

出　　处：《重庆大学学报（自然科学版）》2013年第3期65-70,76,共7页Journal of Chongqing University

基　　金：国家自然科学基金资助项目(50877082);输配电装备及系统安全与新技术国家重点实验室自主研究项目(2007DA10512709303)

摘　　要：针对在大功率LED照明中因滤波电解电容导致的驱动电源与LED的长寿命不匹配问题,提出一种有源纹波补偿的Buck型LED驱动电源。介绍了有源纹波补偿Buck电路的拓扑结构及工作原理,建立了该新型电路的小信号模型。通过对小信号模型进行相关分析,得到了输出电流的表达式,并由此得到了输出电流分别关于输入电压及占空比的传递函数。由传递函数一阶因子的幅频和相频特性分析可知,在设计电路时只要选择合适的参数,就可以将输入扰动完全滤除,使得输出电流为直流。最后通过仿真和实验证实了上述新型电路及其小信号模型的正确性。Considering that the lifespan of electrolytic capacitor in power supply doesn＇t match the LED＇s,the authors propose a Buck converter which employs active ripple compensation circuit to drive LED.The circuit structure and working principle of the new topology is introduced and an equivalent small-signal model is established.The formula of output current and the transfer functions of output current with input voltage and duty cycle are obtained through the small-signal model.According to the magnitude and phase Bode plot of the transfer functions＇ first-order factor,the input disturbance can be completely filtered,and the output current is a DC theoretically,provided the appropriate parameters are selected.Finally,the correctness of the new topology and its small-signal model are confirmed by carrying out the simulations and experiments.

关 键 词：LED驱动电源 电解电容 有源纹波补偿 小信号分析 传递函数 

分 类 号：TM46[电气工程—电器]