摘要现阶段，随着国家电力水平的不断提高，大容量变压器机组的应用也不断增多。作为输电线路中的主要电力设备和输变电的枢纽点，变压器在电力网络的各个环节都起到了无法替代的重要作用，可见对于变压器的保护不容忽视。差动保护是变压器的主要保护之一，变压器在空载合闸或者外部故障切除后恢复供电，差动回路将会流过励磁涌流，如果此时差动装置无法识别，会发生误动作，导致多次合闸不成功.因此，对于励磁涌流的识别与抑制的研究将会是国内外科学家研究的热点。40937
本文将从差动保护的原理展开分析，并进一步对励磁涌流的机理特性进行探讨，利用MATLAB软件对励磁涌流的形成过程进行仿真，并对目前几种涌流的抑制方法进行分析与仿真。
毕业论文关键词： 变压器； 差动保护； 励磁涌流； MATLAB；
Abstract Currently, with the development of the electric power in our country, large capacity transformers are used widely in transmission system and distribution system. As the main electrical equipment and the pivot point in power transmission system, transformer has been played an irreplaceable role in the every place. Therefore the protection of transformer cannot be ignored. At present， the differential protection has been one of the main protections of transformer. When the unload power transformer is switched on the power system or in the process that a fault, outside the protection zone, is cleared, the magnetizing inrush current will usually be produced .The differential protections relays will maloperate. And it will relate to the failure of load switching. So, the identification and suppression of the inrush current will still be a research focus for relaying researchers in the world.
This paper will be began with the analysis of the differential protection . In further study we will discuss the mechanism characteristics of the inrush current. And the forming process of it will be simulated by MATLAB. In the end of the paper, several suppressions of inrush current at present will be analyzed and simulated.
Key words: Transformer; Differential Protection; Inrush Current; Matlab;
目 录
摘要…Ⅰ
Abstract…Ⅱ
1 绪论1
1.1 本课题的背景及意义…1
1.2本文的主要研究工作…2
2 变压器差动保护 3
2.1变压器的故障与不正常运行工况……3
2.2变压器差动保护的基本原理3
2.2.1变压器差动保护的发展简述……3
2.2.2 变压器差动保护的原理与分析…4
2.3变压器差动保护研究发展现状……7
2.3.1综述……7
2.3.2变压器差动保护的研究现状 …7
2.4本章小结9
3 变压器励磁涌流特性分析及仿真…10
3.1引言…10
3.2变压器励磁涌流产生机理与分析…10
3.2.1 单相变压器的励磁涌流产生机理……10
3.2.2 基于时域分析法的励磁涌流特性分析11
3.2.3 基于变压器磁化特性的励磁涌流原理分析…15
3.2.4三相变压器的励磁涌流特性…20
3.3本章小结……22
4 基于MATLAB的空载合闸励磁涌流仿真23
4.1 MATLAB语言的简介23
4.2 MATLAB的发展与特点……23
4.3 仿真模型的建立……24
4.3.1 仿真原理图……24 变压器励磁电流特性分析:http://www.751com.cn/zidonghua/lunwen_40806.html