5kW移相全桥ZVSDCDC变换器的研究_图文(精)

硕士学位论文

5kW 移相全桥ZVS DC/DC变换器的研究

RESEARCH ON 5kW PHASE-SHIFT FULL BRIDGE

ZVS DC/DC CONVERTER

刘鑫

哈尔滨工业大学

2011年6月

国内图书分类号：TM614 学校代码：10213 国际图书分类号：621.3 密级：公开

工学硕士学位论文

5kW 移相全桥ZVS DC/DC变换器的研究

硕士研究生：刘鑫导师：马洪飞教授申请学位：工学硕士学

科：电气工程

所在单位：电气工程及自动化学院答辩日期：2011年6月授予学位单位：哈尔滨工业大学

Classified Index:TM614 U.D.C:621.3

Dissertation for the Master Degree in Engineering

RESEARCH ON 5kW PHASE-SHIFT FULL BRIDGE

ZVS DC/DC CONVERTER

Candidate ： Supervisor ： Speciality ：

Liu Xin

Academic Degree Applied for：

Prof.Ma Hongfei

Master of Engineering

Power Electronics and Electric Drivers

School of Electrical Engineering and Automation June, 2011

Affiliation ： Date of Defence：

Degree-Conferring-Institution ： Harbin Institute of Technology

哈尔滨工业大学硕士学位论文

摘要

DC/DC变换器是电力电子领域重要组成部分，在能源紧张的今天，提高

DC/DC变换器的效率及功率密度，具有重要的意义。功率器件的发展和软开关技术的提出使变换器高效高功率密度成为可能。

移相全桥ZVS DC/DC变换器是一种能够实现软开关和大功率能量变换的变换器。本文围绕移相全桥ZVS DC/DC变换器的特点，分析了其工作原理、占空比丢失、变压器副边整流二极管振荡、滞后臂软开关实现条件等关键问题，并设计和制作了一款5kW 的原理样机。

第一章介绍了DC/DC变换器的背景及发展方向，其中包括器件、软开关技术和目前DC/DC变换器研究的热点。同时还介绍了全桥变换器常见的控制策略，以及移相全桥变换器常见的问题和国内外学者提出的改进方法。第二章针对课题内

容，分析了移相全桥变换器的工作原理，对各个模态进行了详细的分析，并就移相全桥变换器的几个关键问题进行了详细分析：占空比丢失、ZVS 的实现、损耗分析和整流二极管振荡问题。第三章针对技术指标，设计了一款5kW 的样机，其中包括各器件的选型和相关参数的计算，损耗计算。这些参数计算主要有：全桥开关管电压电流应力的计算与选型、变压器的设计、整流二极管的选择、输出LC 滤波电路的设计、隔直电容的选择、谐振电感电容的选择和死区时间的计算、箝位电路的设计。并根据计算结果使用Saber 软件进行了开环仿真，验证了设计参数的正确性。第四章主要介绍了变换器控制系统分析与设计，其中有控制芯片UCC2895的功能介绍，外围元件的选择与保护与采样电路的设计，移相全桥ZVS DC/DC变换器的小信号模型和利用MATLAB 软件进行反馈回路的补偿设计。第五章给出了实验结果和分析，验证了设计的正确性。

关键词移相全桥；软开关；UCC2895；小信号模型

哈尔滨工业大学硕士学位论文

Abstract

DC/DC converter is a main part of power electronic converter. As the energy problem increasingly concerned in modern society, improving the efficient and power density have the significant advantages. The developing of power device and invention of soft-switching technique make the high efficient and high power density of DC/DC converter possible.

The zero-voltage-switching (ZVS phase-shift full bridge DC/DC converter is an advanced DC/DC converter with soft-switching technology which can achieve high power converting. Based on the characteristics of the converter, this paper analyses the basic operation theory and some typical problems like secondary duty ratio loss and the parasitic oscillation of output rectifier diodes as well as the difficulty for lagging legs achieve ZVS. The simulation and experiments are also given.

Firstly, this paper introduces the background and development of the converter, including power device and soft-switching technology and the hot points in researching DC/DC converter as well as some typical problems and some improvements. Secondly, this paper analyses the basic operation theory and some typical problems like secondary duty ratio loss and the parasitic oscillation of output rectifier diodes and power losses as well as the difficulty for lagging legs achieve ZVS. Thirdly, this paper calculates the main parameters including the selection of bridge MOSFET and the design of transformer as well as the output filter and so on. The last of the third part uses the software SABER to simulate the main circuit to verify the correction of the calculations. Fourthly, this paper introduces the control system of the converter including the

UCC2895 chip, sampling circuit, protection circuit, and the small signal model of the converter, as well as the compensation of the feedback loops.

Eventually, the paper explains the experimental result and analyzes the result in detail.

Keywords phase shift full bridge, soft-switching, UCC2895, small signal model 哈尔滨工业大学硕士学位论文

目录

摘要............................................................................................. I

Abstract .......................................................................................... II

第1章绪论 (1)

1.1 DC/DC变换器背景及发展方向 (1)

1.1.1 电力电子器件是主要推动力 (1)

1.1.2软开关技术概述 (1)