電力發(fā)電機保護Powergeneratorprotection情境三：電力變壓器定子繞組的匝間短路保護ScenarioIII:Turn-to-turnShortCircuitProtectionofPowerTransformerStatorWinding目錄頁CONTENTSPAGE匝間短路每個分支的匝間或分支之間的短路。單元件式橫聯(lián)差動保護01Unit-typetransversedifferentialprotection縱向零序電壓原理的匝間短路保護02Turn-to-turnshortcircuitprotectionbasedonlongitudinalzero-sequencevoltageprincipleTurn-to-turnshortcircuitreferstotheshortcircuitthatoccursoneachbranchorbetweenbranches.單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection0101單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection（b）·UVW橫差TA縱差TA·····縱差TA縱差TA·機殼

1．保護的接線方式及其特點Protectionwiringmodeandcharacteristics（a）

UVW橫差TA縱差TA·····縱差TA縱差TA機殼01單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection

2．保護的原理分析Principleanalysisofprotection當定子繞組的同分支匝間短路時01Incasethesamebranchofstatorwindingisshort-circuitedbetweenturns01單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection

2．保護的原理分析Principleanalysisofprotection定子繞組不同分支間發(fā)生短路時02Incaseshortcircuitoccursbetweendifferentbranchesofstatorwinding01單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection2圖9－6單元件式橫聯(lián)差保護原理接線圖Figure9-6Schematicwiringdiagramofunit-typetransversedifferentialprotection1-三次諧波濾過器1-Thirdharmonicfilter2－帶有延時的保護裝置2-Protectiondevicewithtimedelay

2．保護的原理分析Principleanalysisofprotection保護的接線03Protectionwiring01單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection保護接線較簡單，靈敏度較高保護存在死區(qū)：當α很小時或者不同分支間的短路匝數(shù)相同時,保護不能動作

2．保護的原理分析Principleanalysisofprotection評價04EvaluationSimpleprotectionwiringandhighsensitivityDeadzoneofprotection:Incasethatαisverysmallorthenumberofshortcircuitturnsbetweendifferentbranchesisthesame,theprotectioncannotoperate01單元件式橫聯(lián)差動保護Unit-typetransversedifferentialprotection需增設(shè)0.5～1秒的延時，以躲過轉(zhuǎn)子回路的瞬時兩點接地故障。動作電流為

IOP

3．保護的整定原則SettingprincipleofprotectionTheoperationcurrentisIOPAnd0.5~1sdelayisrequiredtoavoidtheinstantaneoustwo-pointgroundingfaultoftherotorcircuit.縱向零序電壓原理的匝間短路保護Turn-to-turnshortcircuitprotectionbasedonlongitudinalzero-sequencevoltageprinciple02該保護利用發(fā)電機定子繞組發(fā)生匝間短路時，機端三相對發(fā)電機中性點出現(xiàn)的零序電壓而構(gòu)成。適用于中性點側(cè)沒有6個或4個引出端子的發(fā)電機定子匝間短路。02縱向零序電壓原理的匝間短路保護UnittypetransversedifferentialprotectionItisapplicabletoturn-to-turnshortcircuitofgeneratorstatorwithout6or4leading-outterminalsatneutralpointside.Theprotectioniscomposedofzero-sequencevoltageofgeneratorterminalthree-phasetogeneratorneutralpointincaseofturn-to-turnshortcircuitofgeneratorstatorwinding.02縱向零序電壓原理的匝間短路保護Interturnshortcircuitprotectionbasedonlongitudinalzerosequencevoltageprinciple圖9—9零序電壓匝間短路保護原理接線圖Schematicwiringdiagramofzero-sequencevoltageturn-to-turnshortcircuitprotection

1．保護的構(gòu)成原理Compositionprincipleofprotection02縱向零序電壓原理的匝間短路保護Interturnshortcircuitprotectionbasedonlongitudinalzerosequencevoltageprinciple01TV0的第三繞組沒有輸出電壓，即3U0=0，保護不動作。當發(fā)電機正常運行時IncasethegeneratoroperatesnormallyTV0開口三角形繞組也不會出現(xiàn)零序電壓，保護不會動作。當發(fā)電機內(nèi)部或外部發(fā)生單相接地故障時Incaseofsingle-phasegroundingfaultinsideoroutsidethegenerator02thethirdwindingofTV0hasnooutputvoltage,i.e.3U0=0,andtheprotectiondoesnotoperate.zero-sequencevoltagewillnotappearintheopendeltawindingofTV0,withtheprotectionnotoperating.02縱向零序電壓原理的匝間短路保護Interturnshortcircuitprotectionbasedonlongitudinalzerosequencevoltageprinciple03三相一次對中性點的電壓不再平衡，3U0=0，使零序電壓匝間短路保護動作。當發(fā)電機定子繞組發(fā)生匝間短路時Incaseofturn-to-turnshortcircuitonthegeneratorstatorwinding在構(gòu)成零序電壓匝間短路保護時，需設(shè)置三次諧波濾過器，以提高保護的靈敏度。thevoltageofthree-phaseprimarytoneutralpointisnolongerbalanced,3U0=0,sothatzero-sequencevoltageturn-to-turnshortcircuitprotectionoperates.Inthecaseofformingzero-sequencevoltageturn-to-turnshortcircuitprotection,thethirdharmonicfiltershallbesettoimprovethesensitivityofprotection.02縱向零序電壓原理的匝間短路保護Interturnshortcircuitprotectionbasedonlongitudinalzerosequencevoltageprinciple04零序電壓匝間短路保護原理方框圖Schematicblockdiagramofzero-sequencevoltageturn-to-turnshortcircuitprotection

圖9－10負序功率閉鎖的零序電壓匝間保護原理方框圖Schematicblockdiagramofzero-sequencevoltageturn-to-turnprotectionofnegative-sequencepowerblocking三次諧波濾過器Thirdharmonicfilter斷線閉鎖保護Disconnectionlockingprotection跳閘出口Tripexit123在構(gòu)