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项目五全线快速保护Project5
FastProtectioninAllLines任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
课程负责人:关娇娇、张勇CourseLeader:GuanJiaojiaoZhangYong任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
线路纵联差动保护只适用于短线路,对于长线路纵联差动保护不能采用。Linelongitudinaldifferentialprotectionisonlysuitableforshortline,forlonglinelongitudinaldifferentialprotectioncannotbeused.广义高频保护就是很好解决了纵联差动保护的辅助导引线问题的一类保护。随着解决方式的不同,称谓也不一样,即高频保护、微波保护、光纤保护等。Generalizedhighfrequencyprotectionisakindofprotectionwhichcansolvetheproblemofauxiliaryguidelineoflongitudinaldifferentialprotection.
Withthesolutionofthedifferent,thetitleisnotthesame,thatis,highfrequencyprotection,microwaveprotection,fiberprotection,etc.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
(1)高频保护构成
Compositionofhighfrequencyprotection任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
TrippingRelayprotectionpartReceiverSenderHighfrequencyprotectionHighfrequencychannelReceiverSenderRelayprotectionpartTripping(2)微波保护
Microwaveprotection任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
Channel(space)TrippingRelayprotectionpartReceiverSenderRelayprotectionpartTrippingReceiverSenderCommunicationpart(3)光纤保护构成
Compositionofopticalfiberprotection任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
TrippingRelayprotectionpartReceiverSenderCommunicationpartRelayprotectionpartReceiverSenderPhotoelectricconversionPhotoelectricconversionFibrechannelTripping(1)高频通道
Highfrequencychannel“相-地”制高频通道的构成。Thecompositionof"phase-ground"highfrequencychannel.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ReceiverSenderSenderReceiver高频阻波器作用:由电感和电容构成的并联谐振回路,它串联在线路两端,从而将高频信号限制在被保护线路上传递,而不致分流到其他线路上去。HighFrequencyResistorFunction:Aparallelresonantcircuitconsistingofaninductorandacapacitorconnectedinseriesatbothendsofacircuit,therebylimitingthetransmissionofhighfrequencysignalstotheprotectedcircuitratherthandivertingthemtoothercircuits.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ReceiverReceiverSenderSender
耦合电容器的作用:将低压高频设备输出的高频信号耦合到高压线路上。CouplingCapacitor:Couplinghigh-frequencysignalsfromlow-voltageandhigh-frequencyequipmenttohigh-voltagelines.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ReceiverReceiverSenderSender连接滤波器:绕组匝数可以调节的变压器。在其连接高频电缆的一侧串接电容器,连接滤波器与耦合电容器共同组成高频串联谐振回路,让高频电流顺利通过。Connectionfilter:transformerwhosewindingturnscanbeadjusted.
Thecapacitorisconnectedinseriesonthesideofthehigh-frequencycable,andthefilterandthecouplingcapacitorareconnectedtogethertoformahigh-frequencyseriesresonantloop,sothatthehigh-frequencycurrentcanpasssmoothly.ReceiverReceiverSenderSender高频电缆:用来连接高频收、发信机与连接滤波器。Highfrequencycable:usedtoconnectthehighfrequencyreceiverandtransmitterwiththeconnectionfilter.SenderSenderReceiverReceiver在检查调试高频保护时,应将接地刀闸合上,以保证人身安全。放电间隙用以防止过电压对收、发信机的伤害。Whencheckinganddebuggingthehighfrequencyprotection,thegroundingswitchshouldbeclosedtoensurepersonalsafety.
Dischargegapisusedtopreventover-voltagedamagetoreceiverandtransmitter.SenderSenderReceiverReceiver收、发信实际为一体机,收信部分具有放大、解调接收的高频信号的作用。Receivingandsendingareactuallyintegratedmachines,andthereceivingparthasthefunctionofamplifyinganddemodulatingthereceivedhigh-frequencysignals.SenderSenderReceiverReceiver启动方式:Startingmethod故障启动发信长时发信移频发信FailuretostartsendingmessagesLonglettersFrequentmovingletter任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
(2)高频信号与高频电流关系Relationshipbetweenhighfrequencysignalandhighfrequencycurrent故障启动方式:电力系统正常运行时收发信机不发信,通道中无高频电流。当电力系统故障时,起动元件启动收发信机发信。Faultstartmode:whenthepowersystemisrunningnormally,thetransceiverdoesnotsendmessages,andthereisnohigh-frequencycurrentinthechannel.
Whenthepowersystemfails,thestarterelementstartsthetransceivertosendmessages.优点:对邻近通道的影响小,可以延长收发信机的寿命。Advantages:littleimpactonadjacentchannels,canextendtransceiverlife.缺点:必须有启动元件,且需要定时检查通道是否良好。Disadvantages:Musthaveastarterelement,andneedstoperiodicallycheckthechannelisgood.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
长期发信方式:电力系统正常运行时,收发信机连续发信,高频电流持续存在,用于监视通道是否完好。而高频电流的消失代表高频信号。Long-termsendingmode:whenthepowersystemisrunningnormally,thetransceiversendsmessagescontinuouslyandthehigh-frequencycurrentcontinuestoexist,whichisusedtomonitorwhetherthechannelisingoodcondition.
Thedisappearanceofthehighfrequencycurrentrepresentsthehighfrequencysignal.优点:通道的工作状态受到监视,可靠性高。Advantages:theworkingstatusofthechannelismonitored,andthereliabilityishigh.缺点:增大了通道间的干扰,并降低了收发信机的使用年限。Disadvantages:increasestheinterferencebetweenchannelsandreducestheservicelifeofthetransceiver.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
移频发信方式:Movefrequencysignalsendingmode正常运行时发出频率的高频电流,用于监视通道。Highfrequencycurrentoffrequencyf2isemittedduringnormaloperationformonitoringchannels.故障时,收发信机发出频率为的高频电流,频率为的高频电流代表高频信号。Whenafaultoccurs,thetransceiveremitsahigh-frequencycurrentoffrequencyF2,whichrepresentsahigh-frequencysignal.(3)高频信号的作用
Theroleofhighfrequencysignals任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ProtectiveelmentsProtectiveelmentsSignallockingSignalallowingSignaltrippingTrippingpulseTrippingpulseTrippingpulseProtectiveelments闭锁信号是阻止保护动作于跳闸的信号。换言之,无闭锁信号是保护作用于跳闸的必要条件。Thelatchingsignalisasignalthatpreventstheprotectionactionfromtripping.
Inotherwords,non-latchingsignalisanecessaryconditiontoprotectagainsttripping.允许信号是允许保护动作于跳闸的信号。有允许信号是保护动作于跳闸的必要条件。Theallowablesignalisthesignalthatallowstheprotectionactiontotrip.
Permissionsignalisanecessaryconditiontoprotectactionfromtripping.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ProtectiveelmentsProtectiveelmentsProtectiveelmentsTrippingpulseTrippingpulseTrippingpulseSignallockingSignalallowingSignaltripping跳闸信号是直接引起跳闸的信号,收到跳闸信号是跳闸的充要条件。Trippingsignalisthesignalthatdirectlycausestripping,andreceivingthetrippingsignalisanecessaryandsufficientconditionfortripping.3、高频闭锁方向保护Highfrequencyblockingdirectionalprotection任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ProtectiveelmentsProtectiveelmentsProtectiveelmentsSignallockingTrippingpulseTrippingpulseTrippingpulseSignalallowingSignaltripping原理:根据被保护线路两侧的方向元件分别对短路的方向作出判断,并利用高频信号作出综合判断,进而决定是否跳闸的一种保护。Principle:accordingtothedirectionelementsonbothsidesoftheprotectedlinetojudgethedirectionoftheshortcircuit,andusethehighfrequencysignaltomakeacomprehensivejudgment,andthendecidewhethertotripaprotection.发信方式:国内广泛应用的高频闭锁方向保护用故障启动发信方式,并规定线路两端功率由母线指向线路为正方向,由线路指向母线为反方向。Sendingmode:thehighfrequencyblockingdirectionprotectionwhichiswidelyusedinChinausesthefaultstartsendingmode,anditisstipulatedthatthepoweratbothendsofthelinepointstothelinefromthebustothepositivedirection,andthelinepointstothebustothenegativedirection.要求:故障时在启动元件灵敏度范围内应可靠启动发信及启动保护。Requirement:Incaseoffailure,thetransmitterandprotectionshouldbereliablystartedwithinthesensitivityrangeofthestarterelement.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
方向元件:正向时使高频收、发信机停信。反向时,高频收、发信机继续发信。Directionelement:tostopthehighfrequencyreceiverandsenderintheforwarddirection.
Inthereversedirection,thehighfrequencyreceiverandtransmittercontinuetosendmessages.电力系统正常运行时,启动元件不启动,高频收、发信机不发信,保护不开放。Whenthepowersystemisrunningnormally,thestartingelementdoesnotstart,thehigh-frequencyreceiverandtransmitterdonotsendmessages,andtheprotectionisnotopen.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
StartingelementsPowerdirectionelementWiringdiagramProtectiveblockdiagramTripSenderReceiverChannelForbiddenexitForbiddenexit任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitSenderReceiverTripChannel当BC线路故障时:线路AB、BC上的高频保护均分别起动发信。WhentheBClinefails:thehighfrequencyprotectiononlineABandBCstartssendingmessagesrespectively.保护1方向元件判断正方向,与门有输出,经t2延时使本侧高频收、发信机停信,另一方面经禁止门2准备出口跳闸。因保护2的方向元件判断故障为反方向,与门无输出,高频收、发信机连续发出高频信号,闭锁本侧保护。Theprotection1directionelementjudgesthepositivedirectionandhasanoutputwiththedoor.AftertheT2delay,thehighfrequencyreceiverandsenderatthissidewillstopthemessage.Ontheotherhand,thegate2willpreparetheexittrip.
Becausethefaultofthedirectionelementofprotection2isjudgedtobeintheoppositedirection,andthereisnooutputfromthegate,thehigh-frequencyreceiverandtransmittersendouthigh-frequencysignalscontinuouslytoblocktheprotectionofthelocalside.WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitTripSenderReceiverChannel记忆元件KT1的作用是防止外部故障切除后,近故障点侧的保护启动元件先返回停止发信,而远故障点侧的启动元件和功率方向元件后返回,造成保护误动作跳闸。ThefunctionofmemoryelementKT1istopreventtheprotectionstartingelementnearthefaultpointfromreturningtostopsendingaftertheexternalfaultisremoved,whilethestartingelementandpowerdirectionelementatthefarfaultpointreturntostopsendingaftertheexternalfaultisremoved,resultingintheprotectionmisoperationtripping.WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitTripSenderReceiverChannel4、相差高频保护
Differentialhighfrequencyprotection原理:比较被保护线路两侧电流的相位,即利用高频信号将电流的相位传送到对侧去进行比较,称为相差高频保护。Principle:Comparethephaseofthecurrentonbothsidesoftheprotectedline,thatis,thephaseofthecurrentistransmittedtotheoppositesidebyusingthehighfrequencysignalforcomparison,whichiscalledthephasedifferencehighfrequencyprotection.假设:线路两侧的电势同相,系统各元件的阻抗角相同(实际上有差别的)。Assumption:thepotentialonbothsidesofthelineisinthesamephase,andtheimpedanceAngleofeachelementinthesystemisthesame(actuallythereisadifference).任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ProtectionProtectionThesamephaseReverse,180degreesoutofphase为实现比相,须把线路对端的电流的信号传送到本端且能代表原工频电流的相位,由比相系统给出比较结果。Inordertorealizethephasecomparison,thecurrentsignaloftheoppositeendofthelinemustbetransmittedtothisendandcanrepresentthephaseoftheoriginalworkingfrequencycurrent.Thecomparisonresultisgivenbythephasecomparisonsystem.若两侧电流相位差近于0°时,保护判断为被保护范围内部故障,应瞬时动作切除故障。Ifthephasedifferencebetweenthetwosidesofthecurrentiscloseto0°,theprotectionisjudgedtobeaninternalfaultwithintheprotectedrange,andthefaultshouldberemovedbyinstantaneousaction.若两侧流相位差接近于180°时,保护判断为外部故障,应可靠将保护闭锁。Ifthephasedifferencebetweenthetwosidesoftheflowiscloseto180°,theprotectionisjudgedtobeanexternalfault,andtheprotectionshouldbereliablylocked.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
当短路电流为正半周时,高频发信机发出高频信号,而在负半周时则不发出信号。Whentheshortcircuitcurrentispositivehalfcycle,thehighfrequencytransmittersendsoutthehighfrequencysignal,butdoesnotsendoutthesignalatthenegativehalfcycle.当被保护范围内部故障时,由于两侧同时发出高频信号,也同时停止发信。在两侧收信机收到的高频信号是间断的。Whenthefaultoccurswithintheprotectedrange,thetransmissionstopsatthesametimebecausebothsidessendouthighfrequencysignals.
Thehighfrequencysignalsreceivedbythereceiversonbothsidesareintermittent.
当被保护范围外部故障时,由于两侧电流相位相差180°,线路两侧的发信机交替工作,收信机收到的高频信号是连续的高频信号。Whenthefaultoccursoutsidetheprotectedrange,duetothecurrentphasedifferenceof180°onbothsides,thetransmitteronbothsidesofthelineworksalternatively,andthehigh-frequencysignalreceivedbythereceiveriscontinuoushigh-frequencysignal.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
CurrentwaveformonbothsideshighfrequencysignalonMsidehighfrequencysignalonNsideThehighfrequencysignalreceivedbythereceiveronbothsides结论:(区内故障)两侧收信机收到的高频信号重叠约10ms,保护瞬时动作跳闸。即使内部故障时高频通道遭破坏,不能传送高频信号,但收信机仍能收到本侧发信机发出的间断高频信号,因而不会影响保护跳闸。Conclusion:thehighfrequencysignalreceivedbybothsidesofthereceiveroverlapsabout10ms,whichprotectstheinstantaneousactiontrip.
Evenifthehighfrequencychannelisdestroyedandthehighfrequencysignalcannotbetransmittedduringtheinternalfault,thereceivercanstillreceivetheintermittenthighfrequencysignalsentbythetransmitteronitsside,sotheprotectiontripwillnotbeaffected.保护区外故障:两侧的收信机收到的高频信号是连续的,线路两侧的高频信号互为闭锁,使两侧保护不能跳闸。Faultoutsidetheprotectionzone:thehigh-frequencysignalsreceivedbythereceiversonbothsidesofthelinearecontinuous,andthehigh-frequencysignalsonbothsidesofthelineblockeachother,sothattheprotectiononbothsidescannottrip.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
小结:1)高频闭锁方向保护是比较线路两侧功率方向,两侧均为正方向时保护动作;有一侧为反方向时,闭锁保护。Summary:1)Highfrequencyblockingdirectionalprotectionisaprotectionactionwhenthepowerdirectionsonbothsidesofthelinearecomparedandbothsidesareinpositivedirections;
Whenonesideisintheoppositedirection,lockprotection.2)相差高频保护是比较线路两侧电流的相位,相位相近时保护动作;反相时保护闭锁。Differencehighfrequencyprotectionistocomparethephaseofthecurrentonbothsidesoftheline,theprotectionactionwhenthephaseisclose;
Protectionlatchduringphasereversal.发信方式:故障发信、长期发信、移频发信。Sendingmode:faultsending,long-termsending,movingfrequentsending.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
高频信号:跳闸信号、允许信号、闭锁信号。Highfrequencysignal:trippingsignal,allowingsignal,blockingsignal.高频电流与高频信号关系:长期发信,高频电流消失代表高频信号。故障发信,高频电流代表高频信号。Therelationshipbetweenhighfrequencycurrentandhighfrequencysignal:sendingsignalsforalongtime,thedisappearanceofhighfrequencycurrentrepresentsthehighfrequencysignal.
Faultsending,highfrequencycurrentrepresentshighfrequencysignal.移频信号:高频电流代表高频信号。Frequencyshiftsignal:thehighfrequencycurrentrepresentsthehighfrequencysignalf2.任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
光纤通道容量大、抗腐蚀、敷设及检修方便,可节省大量有色金属;可解决纵联保护中导引线保护及高频保护的通道易受电磁干扰、高频信号衰耗等问题。Thefiberchannelhaslargecapacity,corrosionresistance,convenientlayingandmaintenance,andcansavealotofnon-ferrousmetals.
Itcansolvetheproblemssuchaselectromagneticinterferenceandhighfrequencysignaldecayinthechannelofthelongitudinalprotectionandhighfrequencyprotection.1.架空地线复合光缆(OPGW)的结构、特征Structureandcharacteristicsofoverheadgroundcompositeopticalcable(OPGW)任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
复合光缆地线具有2种功能,一是作为输电线路的避雷线;二是通过复合在地线中的光纤,是传送光信号的介质,可传送音频、视频、数据和各种控制信号,组建多路宽带通信网。Thegroundwireofcompositeopticalcablehastwofunctions.Oneisasalightningconductorfortransmissionlines.
Thesecondisthroughthecompositeopticalfiberintheground,isthetransmissionofopticalsignalmedium,cantransmitaudio,video,dataandavarietyofcontrolsignals,theformationofamulti-channelbroadbandcommunicationnetwork.
2.光纤通信的特点
Characteristicsofopticalfibercommunication1)通信容量大。Largecommunicationcapacity.2)节约大量金属材料Savealotofmetalmaterials任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
3)光纤通信还有保密性好,敷设方便,不怕雷击,不受外界电磁干扰,抗腐蚀和不怕潮等优点。Fiberopticcommunicationalsohastheadvantagesofgoodconfidentiality,convenientlaying,notafraidoflightningstrike,notaffectedbyexternalelectromagneticinterference,corrosionresistanceandnotafraidofmoisture.
4)光纤最重要的特性之一是无感应性能,因此利用光纤可以构成无电磁感应的、极为可靠的通道。Oneofthemostimportantcharacteristicsofopticalfiberisthenon-inductionperformance,sotheuseofopticalfibercanbeconstructedwithoutelectromagneticinduction,extremelyreliablechannel.3、光纤保护的组成
Compositionofopticalfiberprotection任务二输电线路高频保护Task2HighFrequencyProtectioninTransmissionLine
ElectricparametersElectricparametersElectricparametersElectricparametersRelayprotectionRelayprotectionmodulatormodulatormodemmodemPCMtransmitterjointPCMtransmitterjointOpticalcablereceiverOpticalcablereceiverOpticalcablereceiverOpticalcablereceiverOpticaltransceiverOpticaltransceiverMovableconnectorFiberopticcableMovableconnectorMovableconnector由故障判别元件(继电保护部分)和信号传输系统(PCM端机、光端机以及光缆通道)组成Itiscomposedoffaultidentificationelement(relayprotectionpart)andsignaltransmissionsystem(PCMterminal,opticalterminalandopticalcablechannel)PCM端机由PCM调制器和PCM解调器组成。PCM(PulseCodeModulation)调制器的原理是脉冲编码调制。PCMterminalconsistsofaPCMmodulatorandaPCMdemodulator.APCM(PulseCodeModulation)modulatorisbasedonPulseCodeModulation.ElectricparametersElectricparametersRelayprotectionRelayprotectionmodulatormodulatormodemmodemPCMtransmitterPCMtransmitterOpticalcablesenderOpticalcablesenderOpticaltr
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