爱华网变压器励磁涌流识别及抑制的仿真研究
摘 要
本文对变压器励磁涌流问题进行了深入的研究，从最基本的变压器磁路和电路结构出发，详细阐述变压器励磁涌流产生的基本原理，它的存在对常用的变压器保护性能的影响，以及如何在变压器保护中减弱和消除它的影响。
文章在综述了励磁涌流的产生机理后，分析了励磁涌流的产生过程和波形特点，探讨利用电流作判据和现代数字信号处理技术与智能理论作涌流分析等识别励磁涌流进行了比较，并指出各种方法的优缺点。并对一些新的判别技术进行简单介绍和展望。
此外，本文还介绍了目前使用得较为广泛、有效的几种抑制变压器励磁涌流的方法，并详细介绍了其中的选相投切技术的基本原理，分析了变压器空载投切的暂态过程，同时分析了快速合闸策略、延迟合闸策略、同步合闸策略以及相控投切策略这四种控制策略。
最后在仿真软件中搭建变压器模型，对单相变压器励磁涌流和三相变压器励磁涌流进行了PSCAD和MatLab仿真，同时还对带合闸电阻的单相变压器励磁涌流和中性点串电阻的三相变压器励磁涌流进行了对比仿真试验。通过对比分析，证明这两种方法的正确性和可行性。
关键词：励磁涌流 选相投切技术 PSCAD MatLab 仿真
Research for Identification and Inhibition of Transformer
Inrush Current Via Simulation
ABSTRACT
In this paper, issues of transformer inrush current is studied in some depth, The research will be begin from the analyzing basic structure of the magnetic circuit and circuit structure of transformer, and the more detailed principle of inrush current generated is stated, Further, the negative affection on differential protection of transformer by inrush current, and how to weaken and even eliminate its impact is also described in the paper.
This paper reviews the inrush current after the formation mechanism, analysis of inrush current and waveform characteristics of the production process, Explore the use of current as the criterion for identification inrush current and the use of modern digital signal processing technology and intelligent theory of the inrush current surge of identification methods are analyzed and compared with the advantages and disadvantages of each method, and a number of The new identification technology brief and outlook.
In addition, this article also describes the current use was more extensive and effective inhibition of transformer inrush current of several methods and gave details of the election in which controlled switching technology the basic principle, analysis of transformer no-load switching transient process, while discussed rapid closing strategy discussed, delayed closing strategy, simultaneous closing strategy, and switching control strategy with the four control strategies.
Last build transformer model, single-phase transformer inrush current and three-phase transformer inrush current simulation with PSCAD, while also closing resistor with a single-phase transformer inrush current and neutral series resistor to simulate three-phase transformer inrush current compared test. By comparison, the two methods from which to prove the correctness and feasibility.
KEYWORDS：Inrush Current Controlled Switching PSCAD MatLab
simulation
目 录
第一章 绪论 ...................................................................................................................... 1
1.1 课题的研究背景与意义 ........................................................................ 1
1.2 变压器励磁涌流研究的现状 ................................................................ 2
1.3 本文的主要工作 .................................................................................... 2
第二章 变压器励磁涌流分析 ....................................................................................... 4
2.1 变压器励磁涌流的产生及特点 ............................................................ 4
2.1.1 单相变压器的励磁涌流 .............................................................. 4
2.1.2 三相变压器的励磁涌流 .............................................................. 7
2.2 励磁涌流的危害 .................................................................................... 8
2.3 空载合闸时变压器磁通的变化 ............................................................ 9
2.3.1 合闸瞬间电压为最大值时的磁通变化 ...................................... 9
2.3.2 合闸瞬间电压为零时的磁通变化 ............................................ 10
2.4 本章小结 ...............................................................................................11
第三章 变压器励磁涌流的识别 ................................................................................ 12
3.1 短路故障电流及其特征 ...................................................................... 12
3.2 利用电流波形特征识别励磁涌流的方法 .......................................... 13
3.2.1 二次谐波制动原理 .................................................................... 13
3.2.2 间断角闭锁原理 ........................................................................ 14
3.2.3 波形对称原理 ............................................................................ 15
3.2.4 采样值差动 ................................................................................ 15
3.2.5 波形比较法 ................................................................................ 16
3.2.6 波形上下对称系数法 ................................................................ 16
13.2.7 周波面积法 ............................................................................ 16 4
3.2.8 波形正弦度特征法 .................................................................... 18
3.3 数字信号原理的识别方法 .................................................................. 19
3.3.1 波形相关性分析法 .................................................................... 19
3.3.2 数学形态法 ................................................................................ 20
3.3.3 误差估计法 ................................................................................ 20
3.4 磁通特性识别法 .................................................................................. 21
3.5 等值电路法 .......................................................................................... 22
3.6 功率差动法 .......................................................................................... 22
3.7 变压器回路方程法 .............................................................................. 23
3.8 励磁涌流识别中现代信号处理技术与智能技术的应用 .................. 23
3.8.1 模糊逻辑的多判据法 ................................................................ 23
3.8.2 神经网路法 ................................................................................ 23
3.8.3 联合时频分析法 ........................................................................ 24
3.9 本章小结 .............................................................................................. 25
第四章 几种常用的抑制励磁涌流的方法 .............................................................. 27
4.1 空载变压器选相投切 .......................................................................... 27
4.2 内插接地电阻 ...................................................................................... 27
4.3 改变变压器绕组的分布 ...................................................................... 28
4.4 在变压器低压侧并联电容器 .............................................................. 28
4.5 本章小结 .............................................................................................. 29
第五章 选相分合闸的基本原理与控制策略 ............................................................ 30
5.1 选相分合闸投切技术的基本原理 ...................................................... 30
5.2 选相分合闸投切三相变压器 .............................................................. 30
5.2.1 快速合闸策略 ............................................................................ 31
5.2.2 延迟合闸策略 ............................................................................ 32
5.2.3 同时合闸策略 ............................................................................ 33
5.2.4 相控投切策略 ............................................................................ 33
5.3 本章小结 .............................................................................................. 33
第六章 系统仿真 ........................................................................................................... 34
6.1 PSCAD/EMTDC在电力系统仿真中的应用 ..................................... 34
6.2 单相变压器励磁涌流仿真分析 .......................................................... 34
6.2.1 无合闸电阻的单相变压器励磁涌流仿真 ................................ 35
6.2.2 带合闸电阻的单相变压器励磁涌流仿真 ................................ 37
6.3 三相变压器励磁涌流仿真 .................................................................. 38
6.3.1 中性点直接接地的三相变压器励磁涌流仿真 ........................ 40
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