一种基于时间序列的CCM Buck变换器瞬态精确解析分析方法

摘要

A new modeling and the analysis methods were proposed for Buck converter in continuous current mode(CCM)in this paper. The models of the zero-state responses and the zero-input responses for Buck converter were esablished. delay characteristic of the responses was found and was expxessed by using a time -sequence. An accurate closed-form analytical solution(symbol form)was obtained in this paper. The analytical solution expresses the relation between the duty and output voltage of converter and is a decoupled form between the inductor current and capacitor voltage.The analytical solution can express the transient state,steady state and ripple of the converter and the switching fiequency were not limited. A Soft-Start strategy for Buck conveter based on digital control was realized by using the method proposed and was more precise and simpler. The simulation experiments showed the validity of the method proposed.%本文提出了一种新的Buck开关变换器(连续导电模式)建模与分析方法.此方法对开关变换器的零状态响应和零输入响应分别建模,并针对开关电路响应延时性的规律,提出了时间序列表示形式,获得了变换器输出的瞬态精确解析解.这种解析解实现了变换器电容电压与电感电流的解耦表示;建立了变换器的输出电压与占空比的函数关系;可表示变换器的瞬态,稳态,以及纹波,且不受开关频率高低的限制.应用本文方法实现的变换器软启动的数字控制算法,具有精确且简便的特点.将本文方法与用Psplce仿真分析进行了比较,实验结果说明了本文方法的正确性和有效性.