某kV电力系统继电保护设计

某110kV电力系统继电保护设计摘要：本次毕业设计的主要内容是110kV电力系统继电保护的配置，并依据继电保护配置原理，对所选择的保护进行整定和灵敏性校验，确定方案中的保护。设计分为八个章节，第三、四章是计算系统的短路电流，确定运行方式；第五章是各种设备的保护配置。其中变压器保护包括保护原理分析、保护整定计算和灵敏性校验，主保护采用的是纵联差动保护和瓦斯保护，两者结合做到优势互补，后备保护是复合电压启动过电流保护。母线保护包括保护原理分析，采用了完全电流差动保护，简单可靠。110kV侧的输电线路采用了距离Ⅰ、Ⅲ保护，由于它的电压等级较高，还考虑了零序电流Ⅰ、Ⅲ保护。对于发电机主保护采用了纵差动保护，后备保护采用了发电机定子绕组接地保护。关键词：短路电流，整定计算，灵敏度，继电保护，微机保护Abstract:Thistimegraduationdesignofthemaincontentsbethe110kVelectricpowersystemafterrelayprotectionofscheme,andaccordingasrelayprotectionschemeprinciple，Tochoiceofprotectioncarryoncompletecalculatewiththedelicateextentcheckout,toassuranceprojectinofprotection.锋T不h绸e为叨d敲e烟s叙i侦g霞n虎闲i暴s缓补d林i掏v拨i耳d灶e叮d障烈i析n裙t裤o帝依e玻i陵g必h寨t僻很c户h续a制p汁t娘e妻r究,恩修c配h肥a伸p皱t涝e冬r车孩3痛求a蚀n界d楼确4过乓i续s库谱c讯a睛l换c粗u穿l逗a信t变i贩o医n乔鸣s跑y绒s揪t命e牵m于唉o喝f担祖s扁h授o域r盆t乎盈c迁i馆r画c尊u距i仪t仰含e薯l鼓e伯c励t荒r诚i换c匆狠c蔑u开r捎r建e凳n献t顺,原瞧a瓦s免s毕u诱r较a赔n馋c震e稀察c茎i谁r系c御u再l论a拦t坡e保孙a厦虎w堡a掏y杜;系纸C愿h狭a颜p弱t陷e促r缴截5良咸i诉s妄婚p绍r步o揭t饲e棋c渠t许i茄o牲n裹撇s活c朵h们e劈m慧e泰晌w谦h惹i统c伯h访晋i枝s对泽v皆a先r臭i圾o两u献s谊泛e隆q诊u爸i汽p卡m六e暗n决t晨s诵.山雄A嘉m茧o打n蔑g桥测t斤h参e假m魔扑t联r甘a御n园s进f屑o高r柱m宫e箱r士隶p凡r咽o汗t质e御c镰t懒i农o烤n民米i杏n铜c岸l启u婚d梅e炕狼p沉r决o鸡t槐e盼c故t暖i碗o伙n数孙p丝r蹄i当n自c姑i扶p厕l芳e挖双a及n次a侧l疲y宣s迎i丝s东,渡洒p润r家o歉t曲e根c挂t萝i炮o贿n谷忆c警o供m天p惕l欲e胆t尊e型臣c宋a肯l示c栽u奏l趋a液t姥e士允a贞n蜻d乒谷d均e雾l盛i酒c瓣a酬t画e浆莲e狡x脏t挤e播n吉t访穿c杯h伸e魔c蹦k蛙o歇u炮t座,景真c阿e牙n自t污r敬a掏l垮押p光r骡o含t裤e们c珍t老i们o却n殊纪i极s非风l格e行n足g需t铁h柴w索a帖y策s潮重a另s张s砖o欲c链i宁a游t理e词d创葡累d真i衣f钱f配e胀r医e矿n贼t穷i谁a贼l秋愈p鞭r辞o亲t动e借c武t盘i衡o孟n龟仅a崇n界d厘熄g程a送s刃浪p且r计o还t铸e权c笛t级i桑o洲n撑,愿明b态o名t买h妥仇c兼o驰m表b蛮i勤n款e循鞠t盗o妙破a蔽t罪t险a拒i五n樱谁a斥d作v算a合n拉t遮a贞g获e添呀t秃o葱也w世i迫t牌h凯率e爪a钻c深h吗侮o猛t译h仆e成r储母r黄e行p秩a地i论r角,拳蓝s夕p缩a鸣r贯e罢聚p抽r笛o日t妻e猪c麻t嚷i助o爬n疲北i蓄s购辟c棚o衣m岔p证o挽u汗n烫d素颠e策l凯e跑c尼t筒r钳i幼c推授v钻o饺l浅t奖a虹g纷e细店s阿t顷a减r核t滴贺c丙o屠n陶d倒u幻c爪t刑拒e始l欲e材c狠t悟r伤i朴c局i唇t出y却己t宜o毒宰f柳l跑o范w构梅p净r另o宏t约e拌c天t靠i歼o圣n收.芦g静e袭n云e橡r去a蹄t冻r旁i揭x们雀l驻i专n雅e近耽p比r爆o殖t傅e究c震t储i丽o所n掌弄i殖n改c馒l抛u寸d云e匠子p这r爆o点t悔e男c笑t舰i宋o饺n衰殃p叼r泽i圣n势c腹i柳p刑l坊e败稳a辩n马a建l脸y护s触i妥s予,圆枪a滥d讯o买p所t滩i蜡o胡n缝毛c涨o嗓m遗p秀l喂e亲t参e捷载d覆i猾f事f赚e里r抛e宵n满t狗i召a伟l涂辛e伞l环e腿c妥t贿r窗i喊c廉锯c闷u要r曲r铃e虫n凉t酷等p窜r往o祝t既e杠c磁t劳i合o笨n介,庆遇s销i望m刮p关l彻e扎挠c多r秘e岩d短i严b动i志l混i盐t斥y镇.佛愉T检h阶e肆叛p愧o误w尽e祸r扒锯l潮i涛n支e门讨历o屯f还捞t泥h品e称及1萍1谨0贫匆k降V娱诉a凤d授o检p纤t稍e截越d闹i届s温t奏a裳n殖c般e忆银Ⅰ称攻,烛询Ⅲ碗早p旅r黎o仅t逃e司c倘t算i佣o舍n脏,难搞b胖e专c凯a离u克s逮e挪源o受f扰佳i差t吉扣o纹f尊料t界h认e齿年e骄l略e办c谦t仆r谁i坝c尿锁v今o锁l指t璃a淡g知e冠伯g械r啦a揪d王e眼虎b丰e傻诱h董i滑g劫h扔e限r珍,考搭a利l兔s缝o溪赚c研o抛n愿s丘i艳d狗e泼r调a源t团i心o移n谨种z哄e酸r傅o鸟遵p淘r膛e臣f奏a坟c意e牺阴e摊l耻e粉c急t晌r默i党c如呆c寨u音r茧r辫e恋n怨t缝肝Ⅰ挤躺,牛浆Ⅲ雕奔p滚r塞o脉t路e闻c宾t砌i蓄o牺n已.舍F从o妄r锈定g俊e验n谱e朴r茧a身t袋o寸r界躬c钥e悲n源t甲r叙a拿l恭粱p颈r荣o膀t头e浴c觉t拨i检o纤n连南a殃d私o亏p盛t企e前点l朗e址n锣g汉t味h渴w秩a洪y刊s糠延a未s骗s削o隙c际i闯a胆t校e巨d吃贿卖d茄i物f布f慌e白r丢e孩n棒t孔i虫a国l犯降p驰r熊o稿t将e匠c喘t吊i恳o友n捉,玩穷s柔p波a娃r哗e芳弱p猾r骑o资t四e公c规t非i情o茄n坛宵a宅d脊o伪p绿t法e梨竟g糟e筒n常e颠r物a避t详o宗r鱼忙寒s钢t绸a挡t串o森r疫蒸c焰o磁n堵n横e苦c惰t揉弯g浮r荐o辫u晨n咽d净漠p规r锹o贵t标e奋c躬t哄i巾o脱n坐.屈K病e冒y子w宾o撇r犁d书s残:衬S为h手o边r祥t挠扎c干i拆r秆c盐u怀i绘t御还e协l交e恐c旦t花r凡i耳c感掏c贷u万r窝r年e也n蛾t央,播哀c西o沟m筒p贫l钞e酱t快e敌望c服a角l怖c香u参l思a爱t少i举o瓣n窄,恭虑d野e零l届i晕c绘a馆t席e着崭e剖x缴t植e燥n尿t碑,血偶r捉e断l锁a铃y焰康p议r处o蚕t捉e殖c屠t翅i脚o馒n即,考速m域i屋c寿r残o比c衬o妻m抗p山u音t础e壤r勾宜p暂r过o得t烈e蜂c偶t证i屋o融n脸目壤录HYPERLINK湿气"图3:输入变量“湿气”(成员函数)为变压器年限模型输入变量"夫喃"图4:输入变量“夫喃”(成员函数)为变压器年限模型Mamdani的模糊推论方法是用来对设备的寿命估计。(1)x是和y是,或x是和y是,在此是关联的含义.如果x是及y是，然后z是(2)x表示湿气,y表示夫喃系作为输入(变量)和z为变压器的老化程度而且是输出变数。,,表现他们各自的功能。规则范围限定在:AND(3)在模糊设置中，是x在的全体值集合而是y在的全体值集合。输出变数"年限"图5:输出变量年限(成员函数)综上所述由于易受影响的输出量(设备寿命)，地心引力运算法则集中用来计算区域Ai和中心区域每元函数(MF)的mi.(4)在此：(5)(6)使用上面的模型,易受影响的输出量既变压器寿命是关于湿气和夫喃系的已被确定和描述在了图6中.图6:变压器年限模型,以湿气和夫喃系当做输入变量为基础V.寿命延长现有变压器数量的寿命延长是一个重要实效的议题。有足够的安全性和涉及操作老化单位方面的环境风险接近外面的监视和评估的载入极限。利用正确及时的评估可以控制老化过程,RCM申请和适当的操作标准落实了广大的剩余寿命与可接受的安全性和可改良的可靠性能达到比较好的有成本效益的利用。经典的诊断用现实做解释，因此RCM对设备延长寿命是至关重要的。通过贯彻适当的操作标准(动力载荷)可以改良现有老化设备的利用和有效率的/有效的维护对维持/升级绝缘系统。由于它在强调失败结果方面定义了失败的问题根源，利用RCM能完成比较好的结果。如图7流程图中所表示，利用RCM可以有效地实现设备延长寿命.RCM有助于经济有效的维护，方便操作,增强安全性而且减少环境的风险。基于在线监听和诊断,倘若可能寿命延长的RCM策略能被比较好实现。-设备的关键部件和他们各自的功能已经完全已知。-设备的可能故障和他们的结果包括所有的系统已知已知，如输出变量,被迫的储运损耗(中断),收入,修理,再磨光,替换费用、安全和环境的∕连带损害。图7:变压器寿命延长和管理流程图VI.总结利用输入变量的湿气和呋喃化合物模糊模型可以预测纸包装变压器使用年限。寿命判断将有助于最大化实现可实行的操作效率。系统可靠性和设备实用性能被确保，通过改良系统性能。过早的故障风险能被最小化。设备及时的翻新、替换或再布置能被规划。正确的操作和维护策略能被改进和贯彻以得到最大的回报。间接的和环境的损害能被有效地最小化。PowerTransformerAgingandLifeExtensionAbstract-Powertransformerisacriticalandexpensiveassetforanypowerutility.Manytransformersaroundtheworldareservingclosetoorbeyondtheirdesignedlie.Thereisanincreasingfocusonmaintenanceandlieextensionofexistingtransformerstomaximizethereturnoninvestment.Transformerfailurestatisticsexhibitthatmostofthefailureshaveoccurredbeforereachingtheirratedlife.Transformerfailuresduetodielectricproblemsarereportedashighas75%.Furnacecompoundspresenceinoilprovideanindicationofsoliddielectricdeterioration.Itisimportanttoidentifythedeteriorationstagesofdielectricsanditsdegreeofsensitivitytowardsaging.Ageingisalsostronglydependentontemperature,oxygenandwaterlevelsinthetransformer.Thetransformerlifecanbemaximizedbycontrollingthesevariables.Thispaperpresentsafuzzylogicbasedapproachtoestimatetheageofapowertransformerusingkeyindicatorssuchasmoistureandfurnacecompounds.IndexTerms-TransformerAgeAssessment,LifeExtension,ReliabilityⅠ.INTRODUCTIONPowertransformer'sagingpopulationhasreachedacriticallevel.Existingassetsthatareclosetotheirexpectedlifearebeingconsideredforfurtherutilizationinordertoreducecapitalexpenditureasthereplacementcostofthesetransformersistoohigh.Sincemanyofthesetransformersareoperatingbeyondtheirratedlife,assetreliabilityunderpeakloadcan'tbeensured.Transformerfailuresareincreasinginnumberandhavingseriousimpactonforcedoutages,blackouts,revenueandenvironment.Transformerinsulationdegradation,acceleratedagingandcatastrophicfailuresoccurduetomanyreasonssuchasextremeoperationalconditions,adverseambientconditions(hightemperatureandhumidityindex),throughfaults,surges(switching/lightning)andgeomagneticstorms.Transformeragingisalsoaccelerated.duetolackofmaintenanceandproperfaultdiagnosis.Thedegradationofinsulationsystemisaccompaniedwiththephenomenonofchangingphysicalparametersoritsbehavior.Insulationpaperandoildegradationproducemoistureandfiurnacewhichareresponsiblefornormalandacceleratedaging.Gasesarereleasedintheinsulationsystemduetooverheating,partialdischarge(PD)andarcing.Also,thepresenceofmoistureplaysanimportantroleinthedegradationandfailureofinsulationchain.Watercontentanditsmovementbetweencelluloseandoilistemperaturedependent.Constantmonitoringoffaultgases,hotspottemperatureandwatercontent(WC)helpsindetectingfaultstypes,intensityand,uptoagoodextent,itslocation.Thermalconditionmonitoringoftransformer(includingloadtapchanger)standsvitalfortransformeroperationalplanninginparticularatpeakloadandatemergencyloading.Acceleratedagingoccursduetoincreaseinmoistureandoxygenlevelintheoil.Moistureandoxygenlevelsaretemperaturedependentandincreasewiththeincreaseintemperaturehumidityindex(THI).Higherlevelofmoistureandoxygencanleadtoabubbleformationthatcancausecatastrophicfailure.Increasedreliabilityofatransformerrequiresanoperationalcriterionthatisbasedonacceptablemoisturelimitsaccordingtoloadandtemperature.Itisvitaltoidentifythesourcesofgassingwiththeirrespectiveseverityandimpactontheassetremnantlife.Dissolvedgasanalysis(DGA)withaccurateinterpretationisoneofthemethodsforidentifyingthetypeandseverityofthefault.OnlineDGA,PDanddiagnosticssuchasfrequencyresponseanalysis(FRA)forwindingmovement,recoveryvoltagemeasurement(RVM)areimportanttoestablishasset'soverallintegrity.Transformerdiagnosticsandmonitoringdataareimportanttodecideontheoperationalcriteria,assetmanagementandreliabilitycenteredmaintenance(RCM)strategiesforlifeextension.Betterassetmanagementcanbeachievedwithon-lineconditionmonitoringandeffectivediagnostics.Endoflifeassessmentwithaccuracyisessentialforanassettoserveforitsextendedlife.Ⅱ.TRANSFORMERAGINGItisdifficulttodeterminetheasset'sconditionandagingprocessasitinvolvesmanyvariablesactingatthesametimeinacomplexmanner.Theagingprocessintheoil/celluloseinsulationsystemunderthermalstressandtheirmeasurableeffectsareduetochemicalreactionsintheinseparabledielectricsystem.Thedielectrictemperatureisacriticalagingparameterthatcausesachangeinthemechanicalandelectricalpropertiesofthematerial.Paperinsulationiscomposedofapproximately40%cellulose.DegreeofPolymerization(DP)isameasurementofaveragenumberofglucoseunitspermolecularchain.Paperinsulation,withDPgreaterthan1000,exhibitshighdielectricandtensileproperties,whereasDPvaluelessthan300showsapaperwithpoordielectricandmechanicalproperties.Presenceofwaterandoxygenintheinsulationsystemacceleratestheagingphenomenon.Moistureisagoodindicatortodeterminetheaging,reliabilityandsafetyofthetransformer.Hydrolysis,PyrolysisandOxidationarethethreemechanisms,actingsimultaneously.Theagingmechanismaffectstheelectricalandmechanicalpropertiesofthedielectrics.111.ENDOFLIFEASSESSMENTResiduallifeofidenticaltransformers,withsameperiodofservice,mayvarybecauseofitsinsulationbehavior.Insulationbehaviordependsontemperature,moisturecontentandoxygeningress.Operatingenvironment(altitude,ambientconditions,sunshineandairflow),dynamicloading,systemimpedance,switchingandlightingsurges(overvoltages),throughfaultsandcontaminationsarethemajorfactorstowardsasset'sacceleratedaging.Economicandendoflifeassessmentareessentialfortheexistingagedassetstoplanforthemaintenance,relocationorretirement.Furnacecompoundandmoisturecontentsarethekeyindicatorsforlifeassessment.Furnacecompoundsaregeneratedduetoinsulatingpaper(cellulose)degradationwithnormalagingaswellasduetoincipientfaults.Duetodegradationprocess,papertensileanddielectricstrengthdecreases.Electromagneticforcesduetothroughfaultcurrenthaveseriousimpactonthepaperlifebyloweringitstensilestrength.Goodcorrelationcanbeobtainedbetweenfurnacecompoundanddegreeofpolymerization(DP).Thereforethefurnacecompoundquantitypresentintheoilisagoodindicatorforlifeassessment.ThetransformeragecharacteristicsbasedonfurnacecompoundpresentindifferentagegroupsisshowninFigure1.REMNANTLIFE(YEARS)Figure1TransformeragingcharacteristicwithrespecttoFuran(C4H4O).Furanincreasesduetoinsulationdegradationwithage.Furansaregeneratedduetooverallriseintemperatureaswellasduetotheheatproducedbyactivefaultinanylocalizedarea.Basedontheanalysis,assetcouldbeidentifiedforfuransproducedduetonormalagingorlocalizedfault.Assetoperatingwithpoorpaperstrengthmayresultincatastrophicfailurewithseriousthreattoenvironmentandcollateraldamages.Tomonitorthepaperdegradationtrend,Furananalysiscanplaykeyroleintheoverallassessment.Itisaveryusefuldiagnosticforassessingwhetherafailedtransformershouldberepaired,rewoundorscrapped.Temperature,oxygenandmoisturearethekeyfactorsinacceleratingtheagingprocess.Operatingtemperatureandambienttemperatureexiststhroughoutthelifeofthetransformer,affectingtheinsulationlife.Studiesandfieldexperienceshowthatgradualincreaseintemperaturereducesthepeakloadinsulationlifeoftheasset.Ariseof7°Celsiusabovenormaloperatingtemperaturedecreasesasset'slifeby50%.Moisture(watercontent)ininsulationchainisproducedduetothermo-kineticdegradationofthepaperaswellagingoftheoil.Moisterpresentintheatmospherepenetratesthroughweaksealantwiththechangeinthepressuregradient.Thewatersolubilityinthetransformermineraloilincreaseswiththeincreaseintemperature.Themoistureinfluencesthedecompositionofthemolecularchain,acceleratesthecelluloseagingprocess,affectingthetensileanddielectricpropertiesoftheinsulationsystem.Dielectricbreakdownstrengthdecreaseswithincreaseinmoisture.Basedonthemoisturepresenceintheinsulationchain,transformerriskassessmentisessentialforitseffectivelifeextensionandbetterassetmanagement,Table1.TABLEIMOiSTURELEVELSANDTRANSFORMERFAILURERISKZONESInsulationAverageMoistureContentAssessment4%EnteringFiskZone5%—6%ConsiderableFailureRisk7%FailureImminentMoistureisexchangedbetweenpaperandoilanditsdynamicsarehighlytemperaturedependent.Moisturedynamicsfrompapertooilincreaseswithincreaseinthetemperature,butwiththedecreaseintemperaturethemoisturemovesbacktothepaperslowly.ThestandardmethodformeasuringthemoistureinoilisKaralFischerreactiontest(ASTMD1533).Thistestishighlyrecommendedandiswidelyusedduetoitshighselectivityandsensitivity.Watercontentintheinsulationsystemshouldbekepttoaminimumtomaintaintherequireddielectricproperties.Thetransformeragecharacteristicsbasedonmoisturecontents,presentindifferentagegroupsisshowninFigure2.REMNANTLIFE(YEARS)Figure2:TransformeragingcharacteristicswithincreaseinmoistureContentduetoagingandthermo-kineticdegradation.IV.LIFEESTIMATIONMODELUSINGFUZZYLOGICUsuallyfuranandmoisturearegeneratedsimultaneouslyinaverycomplexmannerandarekeyfactorsinidentifyingasset'sremnantlife.Presenceofbothhasseriousimpactontheassetperformanceandlife,ignoringonecouldmisleadtheestimation.Thefuzzylogicmodelingandanalysishasbeencarriedouttogetbetterasset'sremnantlifeestimation.Figure3&4representsthemoistureandfuransasinputvariablesforthelifeestimationfuzzylogicmodel.Figure5representstheasset'sageasanoutputvariableofthemodel.Inputvariable“Moisture”Figure3:Inputvariable“Moisture”(membershipfunctions)fortransformeragemodelInputvariable“Furan”Figure4:Inputvariable“Furan”(membershipfunctions)fortransformeragemodelMamdani'sfuzzyinferencemethodisappliedtoestimatetheasset'slife.(1)Wherexisandyis,orxisandyisandsoonasaconjunctionofimplications.IFxisANDyis，THENzis(2)Wherexrepresentsthemoisture,yrepresentsfuranasinputs(variables)andztheageofthetransformerandistheoutputvariable.,thenrepresenttheirrespectivemembershipfunctions.Theextenttowhicharuleisactivated:AND(3)Whereisthemembershipvalueofxinthefuzzysetandisthemembershipvalueofyinthefuzzyset.outputvariable“Age”Figure5:outputvariableage(membershipfunctions)Defuzzificarion:Forcrispoutput(assetlife),centerofgravityalgorithmisusedtocalculatetheareaAiandcenterofareaMiforeachmemberfunction(MF).(4)Where:(5)(6)Usingtheabovemodel,thecrispoutput"transformerage"withrespecttomoistureandfuranisdeterminedandisrepresentedinFigure6.Figure6:transformeragemodel,basedonmoistureandFuranasinputvariablesV.LIFEEXTENSIONLifeextensionofexistingtransformerpopulationisanimportantissuefortheutilities.Thereisanamplesafetyandenvironmentalriskinvolvedinoperatingagedunitsclosetoloadinglimitswithoutsurveillanceandassessment.Agingprocesscanbecontrolledwithaccurateintimeassessment,RCMapplicationandproperoperationalcriteriaimple