基于通用平均技术的开关变换器建模研究

Research on switching converter modeling based on general average technology

开关变换器是一类其内部电路结构随时间变化的非线性系统,通过经典控制理论寻求该系统的解析解并对其进行分析与设计,难以描述系统的非线性暂态特性,故需要建立基于变换器实际拓扑结构的数学模型。为了改善常见的开关变换器建模方法的不足之处,采用通用平均技术,以两类典型的开关变换器为研究对象建立其数学模型并进行仿真,仿真结果与实际电路精准模型进行比对,验证且凸显了通用平均模型具有瞬时性、准确性、普适性的特点。同时,通用平均技术与传统的开关变换器建模方法相比,较为细致地描绘且刻画了开关变换器状态变量中的纹波分量,从而解决了开关变换器的非线性特性问题,使其转化为线性时不变系统,极大地简化与便捷了后续对开关变换器的分析与控制。

Switching converter is a kind of nonlinear system whose internal circuit structure changes with time.It is difficult to describe the nonlinear transient characteristics of the system by seeking the analytical solution by means of classical control theory and analyzing and designing it.Therefore,it is necessary to establish a mathematical model based on the actual topology of the converter.However,in order to improve the shortcomings of common switching converter modeling methods,the general average technology is used to establish the mathematical model of two types of typical switching converters and conduct simulation.The simulation results are compared with the actual circuit accurate model,which verifies and highlights the instantaneous,accuracy and universality of the general average model.At the same time,in comparfison with the traditional modeling method of switching converter,the general average technology can describe and depict the ripple component in the state variable of switching converter in detail,so as to solve the nonlinear characteristics of switching converter and transform it into a linear time invariant system,which greatly simplifies and facilitates the subsequent analysis and control of switching converter.