400W级DC – DC升压式开关电源的设计.doc

PAGE PAGE 17摘 要 本文介绍了一种400W级DC–DC升压式开关电源系统。分析了推挽升压变换器的基本结构，和基于SG3525为控制核心、采用变压器隔离反馈、全桥整流滤波的系统方案，设计了中小功率升压开关电源。实验结果表明，本系统控制策略简单有效、电路工作稳定性强、系统自我保护功能完善、输出的直流电平稳定、电压纹波小、带载能力较强、整机效率高，从而验证了系统方案的正确性、稳定性和可行性。关键词：开关电源；推挽升压；隔离反馈；AbstractThis article describes a kind of switching power supply system with 400W level and the DC - DC booster. It analyzes the push-pull booster converter's basic structure, which is based on the SG3525 core control and uses a system plan of the transformer-isolated feedback and the entire bridge rectification filter to design the middle and low power pressure-rising switching power supply system. The result of experiment has shown that the control strategy of this system is simple and effective, and that circuit works in strong stability, and the system has a complete self-protection function and DC outputs stably and the voltage ripple is small, the belt having a stronger bearing ability, the whole machine being high efficiency. Therefore, this system plan has been verified to be correct, firm and feasible.Key words: switching power supply；push-pull boost；Isolated feedback；目 录 TOC \o "1-3" \h \z \u HYPERLINK \l "_Toc324875269" 一、引言 PAGEREF _Toc324875269 \h 1 HYPERLINK \l "_Toc324875270" 1.1、DC-DC升压开关电源的研究背景及现状 PAGEREF _Toc324875270 \h 1 HYPERLINK \l "_Toc324875271" 1.2、本设计主要研究内容 PAGEREF _Toc324875271 \h 1 HYPERLINK \l "_Toc324875272" 二、系统硬件电路设计 PAGEREF _Toc324875272 \h 2 HYPERLINK \l "_Toc324875273" 2.1、系统工作原理分析 PAGEREF _Toc324875273 \h 2 HYPERLINK \l "_Toc324875274" 2.1.1、系统结构框图 PAGEREF _Toc324875274 \h 2 HYPERLINK \l "_Toc324875275" 2.1.2、升压电路选型及工作原理 PAGEREF _Toc324875275 \h 2 HYPERLINK \l "_Toc324875276" 2.2、驱动电路设计 PAGEREF _Toc324875276 \h 4 HYPERLINK \l "_Toc324875277" 2.3、功率电路设计 PAGEREF _Toc324875277 \h 6 HYPERLINK \l "_Toc324875278" 2.3.1、开关管电路 PAGEREF _Toc324875278 \h 6 HYPERLINK \l "_Toc324875279" 2.3.2、整流电路 PAGEREF _Toc324875279 \h 6 HYPERLINK \l "_Toc324875280" 2.3.3、RC吸收电路设计 PAGEREF _Toc324875280 \h 6 HYPERLINK \l "_