高性能、大功率直流开关电源

摘要

开关电源具有效率高、体积小、重量轻等显著特点。目前世界各国都有广泛的应用，特别是对大容量高频开关电源的研究和开发已成为当今电力电子学的主要研究领域，并派生了很多新的研究方向。本文的主要内容就是研制一种高性能、大功率直流开关电源。

本文详细分析了高性能、大功率直流开关电源的工作原理，并提出了主电路和控制电路的详细设计方案。在此基础上，完成了整个系统的硬件电路设计和软件程序的编制，并对电源装置的硬件和软件进行了调试和修改。

在分析原理的基础上，本文从三相桥式不控整流、全桥变换器、高频变压器、滤波电路等环节对该系统的主电路进行了阐述，同时探讨了该电源系统实现大功率的解决方案，即采用多个电源模块并联运行。本文还探讨了多个电源模块并联运行时的自动均流技术，并详细介绍了基于平均值的自动均流电路。在电压调节环节上，详细分析了基于UC3825控制芯片的PWM控制电路。

本文研制的直流开关电源具有输出电压可调、输出电流大、纹波小等特点，而且还具有换档、远程控制等功能。实验结果表明它基本达到设计要求，从而验证了理论分析的正确性，具有广阔的应用前景。

关键词:DC-DC变换器，开关电源，均流，高频变压器，PWM控制

ABSTRACT

Switching power has many remarkable characteristics such as high efficiency,smallness and lightness. Countries all over the world have extensive application in switching power, especially research on large capacity high-frequency switching powernowadays has already become the main research field of power electronics and many new research directions has derived from it. The main content of this paper is to develop a kind of high performance, large capacity adjustable switching power.

This paper has analyzed the theory of high performance, large capacity adjustable switching power in detail, and has proposed the main circuit and control circuit designation. On this basis, this paper schemed out the hardware circuit and software and has carried on the debugging and modification of the hardware and software of the switching power.

On the basis of analyzing the theory, this paper has discussed 3-phase uncontrolled rectifier, the full-bridge converter, high-frequency transformer, and filter of the main circuit of this switching power system. This paper explained the solution of this large capacity power system at the same time, namely some power modules are to be connected in parallel. This paper also has studied current sharing circuit while some power modules were being connected in parallel, in the part of current sharing circuit, this paper has introduced current sharing circuit on the base of average current in detail. On the voltage regulation part, this paper has analyzed PWM control circuit on the basis of UC3825 in detail.

Direct current switching power studied in this paper has many characteristics such as adjustable output voltage, heavy output current, low voltage ripple and so on. It also has the functions of changing output voltage gear, remote-control etc.The experimental result indicated that the switching power has reached the design demand, thus it has proved the exactness of the theory analyses, so, this switching power has wide application fields.

Keywords: DC-DC converter, switching power, current sharing, high-frequency transformer, PWM control