《电力系统继电保护及应用（双语）》课件-输电线路的差动保护

输电线路的差动保护DifferentialProtectionofTransmissionLines目录页CONTENTSPAGE输电线路的纵联差动保护01输电线路的高频保护02输电线路的光纤纵差保护03平行线路横联方向差动保护04LongitudinaldifferentialprotectionoftransmissionlinesHighfrequencyprotectionoftransmissionlinesOpticalfiberlongitudinaldifferenceprotectionforpowertransmissionlinesDifferentialprotectionofparallellinecross-connectiondirection输电线路的纵联差动保护Longitudinaldifferentialprotectionoftransmissionlines01差动保护简介电流保护、距离保护，依靠保护的第I段来快速反应被保护线路始端的一部分故障；对于线路末端的故障，只能靠保护的第Ⅱ段经过一定的延时才能切除。那么怎样才能快速切除被保护线路上任一点所发生的故障呢？速动性Speed可靠性reliability选择性selectivity灵敏性sensitivityntroductiontodifferentialprotectionCurrentprotectionanddistanceprotectionrelyontheprotectionzoneItoquicklyrespondtoapartofthefaultatthebeginningoftheprotectedline;forthefaultattheendoftheline,theprotectionzoneIIcanonlyberemovedafteracertaindelay.Sohowcanwequicklyremovethefaultthatoccursatanypointontheprotectedline?图6-1保护MN~~01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection在线路两端分别安装同型号、同变比的电流互感器（TA），两端TA的极性端均置于靠近母线一侧，二次回路用电缆同极性相连。将保护装置的电流元件并联在TA的二次侧,使线路两端的I引入保护装置。保护的接线1ProtectionwiringInstallcurrenttransformers(TA)ofthesamemodelandsametransformationratioatbothendsoftheline.ThepolarendsofTAatbothendsareplacedclosetothebusbar,andthesecondarycircuitsareconnectedwithcablesofthesamepolarity.ConnectthecurrentelementoftheprotectiondeviceinparalleltothesecondarysideofTA,sothatIatbothendsofthelineisintroducedintotheprotectiondevice.01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection保护的基本工作原理2图6－1反映线路两端电流量的保护接线及电流正方向设：和的正方向为从母线流向被保护的线路保护MN图6-1~~则：（6-1）BasicworkingprincipleofprotectionAssume:Thepositivedirectionofandisfromthebusbartotheprotectedline

Figure6-1:Protectionwiringreflectingthecurrentamountatbothendsofthelineandthepositivedirectionofthecurrent01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection线路正常运行或外部故障时保护装置不动作保护MN~~图6-2WhenthelineisrunningnormallyorwhenthereisanexternalfaultProtectiondevicedoesnotoperate01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection线路内部故障时保护装置动作于跳闸保护MN~~图6-2WhenthereisaninternalfaultinthelineTheprotectiondeviceoperatesontripping01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection利用二次电缆或其它通信手段，将线路两端的保护装置纵向联系起来，将线路两端的电流或其它有关信息传送到对端进行比较判断，以便准确地区分内部与外部故障的保护装置，称为线路的纵联保护。线路的纵联保护传输电流或其它信息TransmitingcurrentorotherinformationPilotprotectionofthelineAprotectiondevicethatusessecondarycablesorothercommunicationmeanstoverticallyconnecttheprotectiondevicesatbothendsoftheline,andtransmitsthecurrentorotherrelevantinformationatbothendsofthelinetotheoppositeendforcomparisonandjudgmentinordertoaccuratelydistinguishbetweeninternalandexternalfaults,iscalledapilotprotectiondevice.01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection理想的情况/Idealsituation在上述分析保护原理时，没有考虑电流互感器的误差。实际上/Infact

Whenanalyzingtheprotectionprincipleabove,theerrorofthecurrenttransformerisnotconsidered.sincethecurrenttransformerstillhasanexcitationcurrentm,whenittransmitstheprimarycurrent1tothesecondaryside,thereareerrorsinbothamplitudeandphase,sothatthesecondarycurrentofthecurrenttransformeronbothsidesofthelineisnolongerequalinvalueandoppositeindirection.01纵联差动保护的基本工作原理Basicworkingprincipleoflongitudinaldifferentialprotection1﷯Ir≠

03磁化特性、励磁电流Magnetizationcharacteristics,excitationcurrent4正常运行时不平衡电流较小，故障时，较大Theunbalancedcurrentissmallerduringnormaloperationandlargerduringfaults.2不平衡电流﷮I𝑛𝑢𝑏﷯UnbalancedcurrentI𝑛𝑢𝑏02不平衡电流UnbalancedcurrentI1MImMI2M稳态情况下的不平衡电流1

（6-2）Unbalancedcurrentundersteadystateconditions02不平衡电流Unbalancedcurrent影响稳态不平衡电流的因素Factorsaffectingsteady-stateUnbalancedcurrent

123

Coremass,loadimpedanceofthesecondarysideofthestructurePrimarycurrent02不平衡电流Unbalancedcurrent电流互感器磁化特性曲线200806016020012018014040100起始区线性区饱和区0.20.40.80.61电流互感器磁10%误差曲线m10Am'10Z’mZb在考虑一次电流最大倍数时，应采用本线路末端母线上故障时流过电流互感器的最大短路电流，并保证在这种最大的一次电流情况下，二次电流的误差不大于10％。

因此ThereforeCurrenttransformermagnetizationcharacteristiccurveCurrenttransformermagnetic10%errorcurvewhenconsideringthemaximummultipleoftheprimarycurrent,themaximumshort-circuitcurrentflowingthroughthecurrenttransformerduringafaultonthebusbarattheendofthelineshouldbeused,anditshouldbeensuredthatunderthismaximumprimarycurrent,theerrorofthesecondarycurrentisnotgreaterthan10%.02不平衡电流Unbalancedcurrent正常运行以及保护范围外部故障时电流互感器的各种误差与励磁电流

、一次电流有关

ImI1

（6-3）

（6-4）TADuringnormaloperationandduringfaultsoutsidetheprotectionscopeVariouserrorsofcurrenttransformerarerelatedtoexcitationcurrentImandprimarycurrentI102不平衡电流Unbalancedcurrent暂态过程中的不平衡电流2idik（a）短路电流ibpiunb（b）不平衡电流外部短路暂态过程中电流波形图6-3

（6-5）TAUnbalancedcurrentduringtransientprocessCurrentwaveformduringexternalshortcircuittransientprocessFigure6-302不平衡电流Unbalancedcurrent01采用型号相同的电流互感器Usecurrenttransformersofthesamemodel02利用速饱和变流器抑制暂态不平衡电流Usingfastsaturationconvertertosuppresstransientunbalancedcurrent03采用快速保护Usequickprotection04引入制动分量Introducerestraintcomponent减小不平衡电流影响的措施3Measurestoreducetheimpactofunbalancedcurrent03比率制动式差动保护的基本原理Thebasicprincipleofratiobrakedifferentialprotection““动作量制动量amountofoperationBrakingcapacity03比率制动式差动保护的基本原理Thebasicprincipleofratiobrakedifferentialprotection动作量最大/Maximumamountofoperation制动量最小/Theminimumamountofrestraint保护装置动作/Protectiondeviceoperates一般取:内部故障Internalfailure03比率制动式差动保护的基本原理Thebasicprincipleofratiobrakedifferentialprotection线路正常运行或外部短路时/Whenthelineisrunningnormallyorwhenthereisanexternalshortcircuit，保护装置不会误动作。Theprotectiondevicewillnotmisoperate.04纵联差动保护的信号通道Signalchannelforlongitudinaldifferentialprotection二次电缆通道电力线载波通道微波通道光纤通道1234Secondarycablechannelpowerlinecarrierchannelmicrowavechannelfiberopticchannel04纵联差动保护的信号通道Signalchannelforlongitudinaldifferentialprotection1二次电缆通道利用二次电缆将电流互感器的二次电流直接传输到线路的另一端。SecondarycablechannelAsecondarycableisusedtotransmitthesecondarycurrentfromthecurrenttransformerdirectlytotheotherendoftheline.04纵联差动保护的信号通道Signalchannelforlongitudinaldifferentialprotection电力线载波通道2利用输电线路加载传送频率为40～500KHz的高频信号。高频通道——高频保护。保护装置保护装置PowerlinecarrierchannelThetransmissionlineisusedtoloadandtransmithigh-frequencysignalswithafrequencyof40to500KHz.Highfrequencychannel-highfrequencyprotection.04纵联差动保护的信号通道Signalchannelforlongitudinaldifferentialprotection微波通道3把需要传送的信息调制成微波信号后，经过空间传播送到对端接收。微波信号的传送距离在50KM左右，超过这个距离需要设微波中继站来转送。ABC微波保护MicrowavechannelAftertheinformationtobetransmittedismodulatedintoamicrowavesignal,itispropagatedthroughspaceandsenttotheoppositeendforreception.Thetransmissiondistanceofmicrowavesignalsisabout50KM.Ifitexceedsthisdistance,amicrowaverelaystationneedstobesetupfortransmission.microwaveprotection04纵联差动保护的信号通道Signalchannelforlongitudinaldifferentialprotection利用光在光导纤维中传送信息的一种通道。光纤通道的优点Advantagesoffiberopticchannel传送信息的容量大中继距离长抗干扰能力强传输性能稳定误码率低光纤通道4FiberopticchannelAchannelthatuseslighttotransmitinformationinopticalfibers.Largecapacityfortransmittinginformationlongrelaydistancestronganti-interferenceabilitystabletransmissionperformanceLowbiterrorrate输电线路的高频保护Highfrequencyprotectionoftransmissionlines0201高频保护的基本原理及分类Basicprinciplesandclassificationofhighfrequencyprotection高频保护的基本原理Basicprinciplesandclassificationofhighfrequencyprotection将线路两端的电气量转化为高频信号，利用高频通道，将此信号送至对端进行比较判断，以便准确地区分内部与外部故障的保护装置。高频保护的分类Classificationofhighfrequencyprotection方向高频保护相差高频保护Aprotectiondevicethatconvertstheelectricalquantitiesatbothendsofthelineintohigh-frequencysignals,andusesthehigh-frequencychanneltosendthissignaltotheoppositeendforcomparisonandjudgmentinordertoaccuratelydistinguishbetweeninternalandexternalfaults.DirectionalhighfrequencyprotectionPhasedifferencehighfrequencyprotection02高频通道Highfrequencychannel相一相制高频通道相一地制高频通道高频通道的构成1Thecompositionofhigh-frequencychannels保护装置保护装置1一输电线路；2一高频阻波器；3一耦合电容器；4一连接滤波器；5一高频电缆；6一放电间隙；7一接地开关；8一高频收、发信机

Phase-to-phasesystemhigh-frequencychannelPhase-to-groundsystemhigh-frequencychannel1-transmissionline;2-highfrequencywavearrester;3-couplingcapacitor;4-connectionfilter;5-highfrequencycable;6-dischargegap;7-groundingswitch;8-highfrequencyreceiverandtransmitter.02高频通道Highfrequencychannel连接滤波器Connectedfilter带通滤波器，使信号频带的高频电流能够顺利通过。阻抗匹配器，避免高频信号在传送过程中发生反射而引起高频能量的附加衰耗。图6-6（a）高频电缆Highfrequencycable接地开关EarthswitchTheband-passfilterallowshigh-frequencycurrentsinthesignalfrequencybandtopasssmoothly.Impedancematchingdevicetoavoidadditionallossofhigh-frequencyenergycausedbyreflectionofhigh-frequencysignalsduringtransmission.02高频通道Highfrequencychannel图6-6（b）高频阻波器Highfrequencywavearrester:将高频信号限制在本线路内传输。它对高频电流呈现很大的阻抗，对于工频电流，阻波器呈现的阻抗很小。耦合电容器（结合电容器）Couplingcapacitor(bondingcapacitor):与连接滤波器共同配合，将高频信号传递到输电线路上，同时使高频收发信机与工频高压输电线路隔离。Limitthetransmissionofhigh-frequencysignalswithinsameline.Itpresentsalargeimpedancetohigh-frequencycurrent,andtopower-frequencycurrent,theimpedanceofthewavearresterisverysmall.Cooperatingwiththeconnectionfilter,ittransmitshigh-frequencysignalstothetransmissionlineandisolatesthehigh-frequencytransceiverfromthepowerfrequencyandhigh-voltagetransmissionlines.02高频通道Highfrequencychannel在调整或检修高频收发信机、连接滤波器时，用它来进行安全接地连接高频收发信机与连接滤波器一般采用同轴电缆对高频收发信机起过电压保护作用发送和接收高频信号的装置高频电缆高频收发信机放电间隙(或避雷器)接地刀闸HighfrequencycableHighfrequencytransceiverDischargegap(orlightningarrester)GroundingswitchCoaxialcablesaregenerallyusedtoconnecthigh-frequencytransceiversandfilters.Providesover-voltageprotectionforhigh-frequencytransceivers.DevicesforsendingandreceivinghighfrequencysignalsUseitforsafetygroundingwhenadjustingoroverhaulinghigh-frequencytransceiversandconnectingfilters.02高频通道Highfrequencychannel正常时无高频电流方式正常时有高频电流方式移频方式高频通道的工作方式2HowthehighfrequencychannelworksNormallythereisnohighfrequencycurrentmodeNormallythereisahighfrequencycurrentmodeFrequencyshiftingmethod02高频通道Highfrequencychannel导频信号闭锁信号--闭锁式工作方式允许信号--允许式工作方式解除闭锁信号跳闸信号高频信号3HighfrequencysignalPilotsignalBlockingsignal-blockingworkingmodePermissionofsignal-permissiveworkingmodeCancelthelocksignalTripsignal02高频通道Highfrequencychannel导频信号闭锁信号--闭锁式工作方式允许信号--允许式工作方式解除闭锁信号跳闸信号用来确认高频通道是否正常的信号，以防止在高频通道故障的情况下，保护装置误动作或拒动作。高频信号3HighfrequencysignalPilotsignalAsignalusedtoconfirmwhetherthehigh-frequencychannelisnormaltopreventtheprotectiondevicefrommisoperationorrefusingtooperateintheeventofahigh-frequencychannelfailure.导频信号允许信号--允许式工作方式解除闭锁信号跳闸信号02高频通道Highfrequencychannel闭锁信号--闭锁式工作方式是制止保护动作将高频保护闭锁的信号，没有收到闭锁信号是保护动作于跳闸的必要条件。高频信号3HighfrequencysignalBlockingsignal-blockingworkingmodeItisasignalthatstopstheprotectionoperationandblocksthehigh-frequencyprotection.Failuretoreceivetheblockingsignalisanecessaryconditionfortheprotectionoperationtotrip.导频信号允许信号--允许式工作方式解除闭锁信号跳闸信号02高频通道Highfrequencychannel闭锁信号--闭锁式工作方式是允许保护动作于跳闸的高频信号，收到允许信号是高频保护动作于跳闸的必要条件。高频信号3HighfrequencysignalPermissionofsignal-permissiveworkingmodeItisahigh-frequencysignalthatallowsprotectiontooperateintripping.Receivingthepermissionsignalisanecessaryconditionforhigh-frequencyprotectiontooperateintripping.导频信号允许信号--允许式工作方式解除闭锁信号跳闸信号02高频通道Highfrequencychannel闭锁信号--闭锁式工作方式当高频保护采用允许式工作方式时，为了防止因本线路故障引起高频通道阻塞等原因造成保护拒动，在本侧保护装置确定为正方向短路。但即收不到对端的允许信号又收不到对端的导频信号，则由本侧保护经延时后发解除闭锁信号，保护在收到本侧的解除闭锁信号后动作于跳闸。高频信号3HighfrequencysignalCancelthelocksignalWhenthehigh-frequencyprotectionadoptsthepermissiveworkingmode,inordertopreventtheprotectionfromrefusingtooperateduetoreasonssuchashigh-frequencychannelobstructioncausedbythefaultofthisline,theprotectiondeviceonthissideisdeterminedtobeashortcircuitintheforwarddirection.However,ifneitherthepermissionsignalnorthepilotsignaloftheoppositeendisreceived,theprotectiononthissidewillsendanunblockingsignalafteradelay.Theprotectionwilltripafterreceivingtheunblockingsignalonthisside.导频信号允许信号--允许式工作方式解除闭锁信号跳闸信号02高频通道Highfrequencychannel闭锁信号--闭锁式工作方式是线路对端保护发来的，直接使保护动作于跳闸的信号。只要收到对端保护装置发来的跳闸信号，不管本侧保护是否起动均动作于跳闸。高频信号3HighfrequencysignalTripsignalItisasignalsentfromtheprotectionattheoppositeendoftheline,whichdirectlycausestheprotectiontotrip.Aslongasthetripsignalfromtheoppositeendprotectiondeviceisreceived,thetripwilloccurregardlessofwhetherthelocalprotectionisactivatedornot.03方向高频保护Directionalhighfrequencyprotection高频方向保护通过比较被保护线路两端的短路功率方向来判断故障点的位置流过故障线路BC两端保护3和4的功率方向均为正非故障线路AB，流过保护2的功率方向为负，流过保护1的功率方向为正高频方向保护1Highfrequencydirectionprotection++__High-frequencydirectionalprotectiondeterminesthelocationofthefaultpointbycomparingtheshort-circuitpowerdirectionatbothendsoftheprotectedline.hepowerdirectionofprotection3and4flowingthroughthefaultlineBCatbothendsispositive.Fornon-faultylineAB,thedirectionofpowerflowingthroughprotection2isnegative,andthedirectionofpowerflowingthroughprotection1ispositive.03方向高频保护Directionalhighfrequencyprotection保护1判定功率方向为正，停止发信保护2判定功率方向为负，继续发信保护1、2均被高频信号闭锁，不动作闭锁式工作方式Lockedworkingmode非故障线路AB故障线路BC保护3判定功率方向为正，停止发信保护4判定功率方向为正，停止发信保护3、4收不到闭锁信号时发出跳闸命令。图6-7高频方向保护基本原理示意图Schematicdiagramofthebasicprinciplesofhigh-frequencydirectionalprotection++__Non-faultylineABFaultylineABProtection1determinesthatthepowerdirectionispositiveandstopssendingmessages.Protection2determinesthatthepowerdirectionisnegativeandcontinuestosendmessages.Protection1and2areblockedbyhigh-frequencysignalsanddonotoperate.Protection3determinesthatthepowerdirectionispositiveandstopssendingmessages.Protection4determinesthatthepowerdirectionispositiveandstopssendingmessages.Whenprotection3and4cannotreceivetheblockingsignal,atripcommandisissued.03方向高频保护Directionalhighfrequencyprotection保护3、4判定功率方向为正，均发允许信号，在分别收到对侧保护装置发来的允许信号后动作于跳闸。允许式工作方式Permissiveworkingstyle故障线路BC非故障线路AB保护2判定功率方向为负，不向对侧发允许信号，不动作保护1判定功率方向为正，收不到保护2的允许信号，不动作图6-7高频方向保护基本原理示意图Schematicdiagramofthebasicprinciplesofhigh-frequencydirectionalprotection++__Non-faultylineABFaultylineBCProtection3and4determinethatthepowerdirectionispositive,bothsendpermissionsignals,andtripafterreceivingthepermissionsignalsfromtheoppositesideprotectiondevicerespectively.Protection2determinesthatthepowerdirectionisnegative,doesnotsendapermissionsignaltotheoppositeside,anddoesnottakeoperation.Protection1determinesthatthepowerdirectionispositive,doesnotreceivethepermissionsignalofprotection2,anddoesnotact.03方向高频保护Directionalhighfrequencyprotection高频距离保护2Highfrequencydistanceprotection通过距离保护的方向元件、阻抗元件测量故障点的位置，利用高频通道传送相关的保护信息。采用闭锁式工作方式的高频距离保护Thelocationofthefaultpointismeasuredthroughthedirectionalelementandimpedanceelementofdistanceprotection,andtherelevantprotectioninformationistransmittedusinghigh-frequencychannels.High-frequencydistanceprotectionusinglatchedworkingmode03方向高频保护Directionalhighfrequencyprotection线路内部故障时保护1判定功率方向为正，停止发信，测量元件动作保护2判定功率方向为正，停止发信，测量元件动作保护1和2收不到闭锁信号时发出跳闸命令线路内部故障时WhenthereisaninternalfaultinthelineProtection1determinesthatthepowerdirectionispositive,stopssendingsignals,andthemeasuringelementoperates.Protection2determinesthatthepowerdirectionispositive,stopssendingsignals,andthemeasuringelementoperates.Protection1and2issueatripcommandwhentheycannotreceivetheblockingsignal.03方向高频保护Directionalhighfrequencyprotection线路内部故障时保护1判定功率方向为正，停止发信，测量元件可能动作保护2判定功率方向为负，继续发信保护1和2均被闭锁不会误动作线路外部故障时WhenthereisanexternalfaultonthelineProtection1determinesthatthepowerdirectionispositive,stopssendingsignals,andthemeasuringelementmayoperate.Protection2determinesthatthepowerdirectionisnegativeandcontinuestosendmessages.Protection1and2arebothblockedandwillnotmalfunction.03方向高频保护Directionalhighfrequencyprotection高频零序电流保护3Highfrequencyzerosequencecurrentprotection在零序电流保护上加装高频设备构成的，用来快速切除高压、超高压线路的接地故障。Itiscomposedofhigh-frequencyequipmentinstalledonthezero-sequencecurrentprotection,whichisusedtoquicklyremovegroundfaultsinhigh-voltageandultra-high-voltagelines.输电线路的光纤纵差保护Opticalfiberlongitudinaldifferentialprotectionfortransmissionlines03输电线路的光纤纵差保护是用光导纤维作为通信信道的纵联差动保护。随着光纤通信技术的发展，光纤产量的增加、价格的下降，光纤通信已经成为电力系统的主要通信方式。随着光纤通信网络在电力系统中的快速普及，光纤纵差保护作为高压输电线路的主保护，将逐步取代高频保护。Opticalfiberlongitudinaldifferentialprotectionoftransmissionlinesisalongitudinaldifferentialprotectionthatusesopticalfibersascommunicationchannels.Withthedevelopmentofopticalfibercommunicationtechnology,theincreaseofopticalfiberproductionandthedecreaseofprice,opticalfibercommunicationhasbecomethemaincommunicationmethodofpowersystem.Withtherapidpopularizationofopticalfibercommunicationnetworksinpowersystems,opticalfiberdifferentialprotection,asthemainprotectionofhigh-voltagetransmissionlines,willgraduallyreplacehigh-frequencyprotection.01光纤通信的特点Characteristicsofopticalfibercommunication1通信容量大2抗干扰能力强3原料资源丰富4线路架设方便LargecommunicationcapacityStronganti-interferenceabilityAbundantrawmaterialresourcesConvenientlineinstallation02光纤通道Fiberchannel将要传输的各路信息，调制成适合在光纤信道中传输的脉冲信号。1调制器Modulator把调制器输出的脉冲电信号调制成光信号。2光源Lightsource图6-9光源中继器光检测器光纤光纤调制器解调器ModulatorLightsourceRepeaterPhotodetectorDemodulatorEachchannelofinformationtobetransmittedismodulatedintoapulsesignalsuitablefortransmissionintheopticalfiberchannel.Modulatethepulseelectricalsignaloutputbythemodulatorintoanopticalsignal.02光纤通道FiberchannelUBLD－UReVT2RcVT110激光器驱动电路原理图

SCHEMATICDIAGRAMOFLASERDRIVECIRCUIT图6-1002光纤通道Fiberchannel用来传送光信号，完成信息传输的任务。纤芯的作用是传导光波，其光折射率为n2

。包层的作用是将光波封闭在光纤中传播，其光折射率为n1。护套也称为涂覆层，由树脂、尼龙、塑料等材料构成，它对光纤起保护作用，同时还增强了光纤的机械强度。包层n1Claddingn1护套Sheath纤芯n2Fibercoren2θ图6－11光纤结构示意图光纤与光缆3/Fiberopticsandcables组成:玻璃纤芯玻璃包层护套Thefunctionofthefibercoreistoconductlightwaves,anditslightrefractiveindexisn2.Thefunctionofthecladdingistoconfinelightwavestopropagateintheopticalfiber,anditslightrefractiveindexisn1.Thesheath,alsocalledthecoatinglayer,ismadeofresin,nylon,plasticandothermaterials.Itprotectstheopticalfiberandalsoenhancesthemechanicalstrengthoftheopticalfiber.OpticalfiberstructurediagramItisusedtotransmitopticalsignalsandcompletethetaskofinformationtransmission.Composition:glassfibercore,glasscladding,sheath02光纤通道Fiberchannel电力特种光缆Powerspecialopticalcable全介质自承式光缆ADSS、架空地线复合光缆OPGW、缠绕式光缆GWWOP、捆绑式光缆AL－Lash、相线复合光缆OPPC等。加强芯Reinforcementcore塑料包皮plasticsheath缆芯/cablecore填充物/fille护套/sheath图6-12光缆结构示意图SCHEMATICDIAGRAMOFOPTICALCABLESTRUCTUREAll-mediaself-supportingopticalcableADSS,overheadgroundwirecompositeopticalcableOPGW,windingopticalcableGWWOP,bundledopticalcableAL-Lash,phasewirecompositeopticalcableOPPC,etc.02光纤通道Fiberchannel光检测器/Photodetectors4本征区－－－－＋＋＋＋PN光检测器用来接收光信号，并将其转换成脉冲电信号。检测器的主要元件为光电二极管光电二极管由P型区、N型区、本征区三部分构成。图6-13Photodetectorsareusedtoreceiveopticalsignalsandconvertthemintopulseelectricalsignals.ThemaincomponentofthedetectoristhephotodiodeThephotodiodeiscomposedofthreeparts:P-typeregion,N-typeregion,andintrinsicregion.02光纤通道Fiberchannel对接收信号进行解码和分路处理5解调器Demodulator对衰减的光波信号进行放大，并对失真的信号波形进行矫正，使光波信号得到再生。6光中继器Opticalrepeater同步电路通过检测对侧发送的同步码，使发送与接收侧的信号时钟保持同步。DecodeanddemultiplexthereceivedsignalThesynchronizationcircuitsynchronizesthesignalclocksofthesendingandreceivingsidesbydetectingthesynchronizationcodesentbytheoppositeside.Amplifytheattenuatedlightwavesignalandcorrectthedistortedsignalwaveformsothatthelightwavesignalcanberegenerated.03光纤纵联电流差动保护的原理Principleofopticalfiberpilotcurrentdifferentialprotection图6－14MNM侧电流差动保护N侧电流差动保护光纤通道MsidecurrentdifferentialprotectionNsidecurrentdifferentialprotectionFiberChannel03光纤纵联电流差动保护的原理Principleofopticalfiberpilotcurrentdifferentialprotection分相差动电流：分相制动电流：突变量差动保护1/Mutationdifferentialprotection分别为线路两侧的相电流突变量设：、突变量差动保护的动作判据，，

（6-6）AssumearethephasecurrentmutationsonbothsidesofthelinePhasedifferentialcurrentPhasebrakingcurrentOperationcriteriaformutationdifferentialprotection03光纤纵联电流差动保护的原理Principleofopticalfiberpilotcurrentdifferentialprotection经电容补偿后的分相差动电流：高定值分相电流差动保护的动作判据高定值分相电流差动保护2/Highfixedvaluesplitphasecurrentdifferentialprotection设：分别为线路两侧的相电流经电容补偿后的分相制动电流：

（6-7）AssumearethephasecurrentonbothsidesofthelineSplit-phasedifferentialcurrentaftercapacitorcompensation：Plit-phasebrakingcurrentaftercapacitorcompensation：Operationcriteriaofhighfixed-valuesplit-phasecurrentdifferentialprotection03光纤纵联电流差动保护的原理Principleofopticalfiberpilotcurrentdifferentialprotection低定值分相电流差动保护的动作判据：低定值分相电流差动保护3Lowfixedvaluesplitphasecurrentdifferentialprotection

（6-8）Operationcriteriaforlow-setsplit-phasecurrentdifferentialprotection:03光纤纵联电流差动保护的原理Principleofopticalfiberpilotcurrentdifferentialprotection零序电流差动保护的动作判据为：4Theoperationcriteriaofzerosequencecurrentdifferentialprotectionare:经电容补偿后的零序差动电流：经电容补偿后的零序制动电流：

（6-9）Zero-sequencedifferentialcurrentaftercapacitorcompensation:Zerosequencebrakingcurrentaftercapacitorcompensation:04纵联电流差动保护的逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection图6－15纵联电流差动保护逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection04纵联电流差动保护的逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection如图6－15所示，当对侧差动保护的压板投入时，与门Y1开放1差动保护正常投入Differentialprotectionisnormallyengaged当对侧差动保护的起动元件动作后、或对侧断路器处在跳闸位置，经或门H1、与门Y1开放与门Y32差动保护起动Differentialprotectionstart本侧差动保护的压板投入时，与门Y2开放通道处在正常工作状态时，与门Y15开放。即与门Y1、Y2、Y15均处在准备开启状态本侧差动保护的起动元件动作后，经与门Y2、Y15、Y3开放差动保护的出口：与门Y12、Y13、Y14、Y21AsshowninFigure6-15,whenthepressureplateoftheoppositesidedifferentialprotectionisputin,theANDgateY1opensWhenthepressureplateofthedifferentialprotectiononthissideisputin,theANDgateY2isopened.Whenthechannelisinnormalworkingcondition,ANDgateY15isopen.Thatis,ANDgatesY1,Y2,andY15areallintheready-to-openstate.Whenthestartingelementoftheoppositesidedifferentialprotectionoperates,ortheoppositesidecircuitbreakerisinthetrippingposition,theANDgateY3isopenedviatheORgateH1andtheANDgateY1.Afterthestartingelementofthedifferentialprotectiononthissideoperates,theexitsofthedifferentialprotectionareopenedthroughtheANDgatesY2,Y15,andY3:ANDgatesY12,Y13,Y14,andY2104纵联电流差动保护的逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection差动保护动作3/Differentialprotectionoperation当保护范围内发生单相接地故障时（假设U相接地），则U相的差动元件动作，经Y4－H4－Y12－H6选跳出口，发U相跳闸指令。Whenasingle-phasegroundfaultoccurswithintheprotectionrange(assumingthattheUphaseisgrounded),theUphasedifferentialelementwillact,andaUphasetripcommandwillbeissuedthroughtheY4-H4-Y12-H6selectedtripoutlet.如果保护范围内U相经高阻接地，U相差动元件拒动。则由零序差动保护动作，经延时后将故障切除。若控制字KG2.8整定为“0”，则零序差动保护经Y7－Y14－H6选跳出口，发U相跳闸指令；如控制字KG2.8整定为“1”，则零序差动保护经H7永跳出口，发三相永久跳闸指令，同时闭锁选跳出口Y12。IftheU-phaseisgroundedthroughhighresistancewithintheprotectionrange,theU-phasedifferentialcomponentrefusestomove.Thenthezero-sequencedifferentialprotectionwilloperateandthefaultwillberemovedafteradelay.IfthecontrolwordKG2.8issetto"0",thezerosequencedifferentialprotectionwillselectthetripoutletthroughY7-Y14-H6andsendaU-phasetripcommand;ifthecontrolwordKG2.8issetto"1",thezerosequencedifferentialprotectionwillThedynamicprotectionsendsathree-phasepermanenttripcommandthroughtheH7permanenttripoutlet,andatthesametimeblocksthetripselectionoutletY12.04纵联电流差动保护的逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection差动保护动作3/Differentialprotectionoperation当线路保护范围内发生相间短路故障时（假设U、V两相短路），则U、V两相的差动元件均动作，经Y4、Y5―Y8―H5－Y13出口；同时闭锁选跳出口Y12。若控制字KG1.0整定为“0”，则发三相跳闸指令；如控制字KG1.0整定为“1”，则发三相永久跳闸指令。Whenaphase-to-phaseshortcircuitfaultoccurswithinthelineprotectionrange(assumingthatUandVphasesareshort-circuited),thedifferentialcomponentsofbothUandVphaseswilloperateandpassthroughtheY4,Y5-Y8-H5-Y13exits;atthesametime,thejump-outexitwillbeblocked.Y12.IfthecontrolwordKG1.0issetto"0",athree-phasetripcommandisissued;ifthecontrolwordKG1.0issetto"1",athree-phasepermanenttripcommandisissued.04纵联电流差动保护的逻辑框图Logicblockdiagramofpilotcurrentdifferentialprotection电流互感器二次回路断线4Currenttransformersecondarycircuitdisconnection保护经H2将零序差动保护的出口Y7闭锁。若控制字KG2.2整定为“1”，则电流互感器二次回路断线时