开关电源的变换之道

A Novel Concept to Analyze Switch Mode Power Supply

文中提出一个新颖的理论，用于分析开关电源各种变换拓扑之间的关系。从基本的降压变换器出发，应用伏秒平衡原理建立了开关电源的基础模型，并提出开关电源的通用表达式，将几种常用的开关电源的变换关系用同一个函数公式进行描述。文中又分析了该开关电源通用表达式在几种典型的边界条件下的应用，从而给出开关电源分类的理论依据。最后例举了这一分析原理在实际工作中的应用案例。

In this paper, a novel concept is proposed to analyze the Switch Mode Power Supply. Based on the buck converter topology, a general model of SMPS is built with the principal of Volt- Second Balance and a general function formula for SMPS is given. From the formula, a basic concept is proposed： the Boost converter and the Buck converter can be described in the same formula, indicating a same physical model. This is an important concept, which means that a boost converter is also a buck converter, so the boost converter and the buck converter can be unified into one model to be analyzed. This paper also analyzes the general formula of SMPS in some typical boundary conditions and proposes a theoretical base of SMPS classifications. At the end of the paper, the principle of this concept is used to set up a 3-level inverter topology as an example. The concept proposed in this paper is a good guidance for the analysis of SMPS.