电流模式控制正激变换器的建模及设计  

Design and Modeling of Current-mode Control Forward Converter

作　　者：赵涛[1,2] 刘汉忠[1] 张永号[1] 沈亚斌[1] 

机构地区：[1]南京工程学院自动化学院,江苏南京211167 [2]南京工程学院,先进数控技术江苏省高校重点建设实验室,江苏南京211167

出　　处：《电力电子技术》2013年第8期4-6,共3页Power Electronics

基　　金：南京工程学院创新基金(CKJB201209);南京工程学院青年基金(QKJA2011005)~~

摘　　要：为优化设计DC/DC变换器控制环路,以提高系统的稳定性和瞬态响应,对DC/DC变换器小信号模型进行研究,给出基于脉宽调制(PWM)控制芯片UC3843的单端正激变换器设计实例和电路分析。建立了电流模式控制(CMC)的单端正激变换器小信号模型,在此基础上推导出正激变换器的系统传递函数。分析了UC3843斜坡补偿原理,给出了采用TL431和光耦构成的反馈补偿网络数学模型。仿真和实验结果表明模型的正确性,所设计的电路具有输入电压变化范围宽、动态响应快、电压调整率和负载调整率高的特点。In order to optimize the design of compensation network for DC/DC converter to elevate the stability and dynamic response of switch-mode power supplies,the small signal model of DC/DC converter is studied.The design example and analysis of a forward converter based on pulse width modulation（PWM） control chip UC3843 is presented. The small signal model of a forward converter used current-mode control （CMC） is introduced, the system transfer fun- ctions of converter are deduced based on it.The operation theory of slope-compensation for UC3843 is analyzed, mathe- matic model of feedback compensation networks comprised by TL431 shunt regulator and optocoupler is discussed.The results of the analysis are simulated and verified through experiment, the designed forward converter has a wide input voltage range, fast frequency response speed, high voltage and load regulation rates, stable output voltage.

关 键 词：变换器 电流模式控制 小信号模型 斜坡补偿 

分 类 号：TM46[电气工程—电器]