基于MatLab的电力变压器建模和仿真分析(1)

目录毕业设计（论文）任务书.......................................................................................4标题...........................................................................................................................6摘要...........................................................................................................................7引言...........................................................................................................................9第一章变压器及Matlab介绍..............................................................................101.1变压器的磁化特性..........................................................................................101.2变压器保护......................................................................................................111.3励磁涌流..........................................................................................................141.4Matlab/Simulink简介.......................................................................................15第二章变压器仿真研究.......................................................................................172.1仿真长线路末端电压升高...............................................................................172.1.1仿真模型如图...............................................................................................172.1.2仿真参数介绍及波形...................................................................................172.2仿真三相变压器T2的励磁涌流...................................................................202.2.1仿真模型如图...............................................................................................212.2.2仿真参数介绍及波形...................................................................................212.3仿真三相变压器外部故障..............................................................................262.3.1仿真模型如图:...............................................................................................262.3.2仿真参数介绍及波形...................................................................................272.4仿真三相变压器T3的励磁涌流...................................................................312.4.1仿真模型如图...............................................................................................3122.4.2仿真参数介绍及波形...................................................................................322.5仿真三相变压器T3的内部故障...................................................................382.5.1仿真T3相间短路（AB相）的模型如图..................................................382.5.2模型参数介绍及波形...................................................................................382.5.3仿真T3匝间短路的模型如图....................................................................422.5.4模型参数介绍及波形...................................................................................42第三章变压器仿真波形分析...............................................................................453.1对励磁涌流进行FFT分析.............................................................................453.2对外部故障进行FFT分析.............................................................................463.3对内部故障进行FFT分析.............................................................................47总结.........................................................................................................................49参考文献.................................................................................................................50附录：外文翻译1..................................................................................................51外文翻译2..............................................................................................................56指导教师评语表.....................................................................................................603基于MatLab/Simulink的电力变压器建模与保护仿真分析PowertransformerprotectionsimulationanalysisandmodelingbasedonMatLab/Simulink4摘要在电力变压器差动保护中，励磁涌流和内部故障电流的判别一直是一个关键问题。文章阐述了励磁涌流的产生及其特性，利用MATLAB对变压器的励磁涌流、内部故障和外部故障进行仿真，对实验的数据波形分析，以此来区分故障和涌流，目的是减少空载合闸产生的励磁涌流对变压器差动保护的影响，提高保护的灵敏性。关键字:变压器；差动保护；励磁涌流；内部故障；外部故障；波形分析5AbstractInpowertransformerdifferentialprotection,discriminationbetweenexcitationinrushcurrentandinternalfaultcurrenthasbeenakeyissue.Thispaperexpoundstheproductionofexcitationinrushcurrentanditscharacteristics,andusesMATLABforthesimulationoftransformerexcitationinrushcurrent,externalandinternalfaultandanalysisoftheexperimentaldatawaveform,soastodistinguishbetweenfaultandinrushcurrent,thepurposeistoreducetotheinfluencewhichtheexcitationinrushcurrentproducedbyno-loadoffhaveonthetransformerdifferentialprotection,improvethesensitivityoftheprotection.Keyword:transformer;Differentialprotection;Excitationinrushcurrent;Internalfault;Externalfault;Waveformanalysis6引言变压器是电力系统的重要电气设备，广泛应用于电力系统的发电、配电和输电等各个环节，因而其安全运行关系到整个电力系统能否连续稳定的工作。随着超高压远距离输电线路在我国越来越多地建成和投入运行，大容量变压器的应用日益增多，对变压器保护运行的可靠性和快速性提出了更高的要求。根据相关文献统计，目前220kV变压器差动保护正确动作率不到70%，远低于其它设备保护的正确动作水平，因此有必要对现有的技术进行深入的研究。无论是传统的模拟式保护，还是目前崛起的微机保护，在变压器差动保护中主要解决两个问题：一是正确鉴别励磁涌流和内部故障短路电流；二是区分外部故障和内部故障。运行经验表明，差动保护能够准确区分内外故障，困此励磁涌流和故障电流的判别是变压器差动保护的关键问题。本文阐述了励磁涌流的产