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.
出处
《电力电子技术》
CSCD
北大核心
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)~~
关键词
变换器
电流模式控制
小信号模型
斜坡补偿
converter
current-mode control
small signal model
slope-compensation
