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項目五全線快速保護Project5

FastProtectioninAllLines任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

課程負責人:關嬌嬌、張勇CourseLeader:GuanJiaojiaoZhangYong任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

線路縱聯(lián)差動保護只適用于短線路,對于長線路縱聯(lián)差動保護不能采用。Linelongitudinaldifferentialprotectionisonlysuitableforshortline,forlonglinelongitudinaldifferentialprotectioncannotbeused.廣義高頻保護就是很好解決了縱聯(lián)差動保護的輔助導引線問題的一類保護。隨著解決方式的不同,稱謂也不一樣,即高頻保護、微波保護、光纖保護等。Generalizedhighfrequencyprotectionisakindofprotectionwhichcansolvetheproblemofauxiliaryguidelineoflongitudinaldifferentialprotection.

Withthesolutionofthedifferent,thetitleisnotthesame,thatis,highfrequencyprotection,microwaveprotection,fiberprotection,etc.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

(1)高頻保護構(gòu)成

Compositionofhighfrequencyprotection任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

TrippingRelayprotectionpartReceiverSenderHighfrequencyprotectionHighfrequencychannelReceiverSenderRelayprotectionpartTripping(2)微波保護

Microwaveprotection任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

Channel(space)TrippingRelayprotectionpartReceiverSenderRelayprotectionpartTrippingReceiverSenderCommunicationpart(3)光纖保護構(gòu)成

Compositionofopticalfiberprotection任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

TrippingRelayprotectionpartReceiverSenderCommunicationpartRelayprotectionpartReceiverSenderPhotoelectricconversionPhotoelectricconversionFibrechannelTripping(1)高頻通道

Highfrequencychannel“相-地”制高頻通道的構(gòu)成。Thecompositionof"phase-ground"highfrequencychannel.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ReceiverSenderSenderReceiver高頻阻波器作用:由電感和電容構(gòu)成的并聯(lián)諧振回路,它串聯(lián)在線路兩端,從而將高頻信號限制在被保護線路上傳遞,而不致分流到其他線路上去。HighFrequencyResistorFunction:Aparallelresonantcircuitconsistingofaninductorandacapacitorconnectedinseriesatbothendsofacircuit,therebylimitingthetransmissionofhighfrequencysignalstotheprotectedcircuitratherthandivertingthemtoothercircuits.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ReceiverReceiverSenderSender

耦合電容器的作用:將低壓高頻設備輸出的高頻信號耦合到高壓線路上。CouplingCapacitor:Couplinghigh-frequencysignalsfromlow-voltageandhigh-frequencyequipmenttohigh-voltagelines.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ReceiverReceiverSenderSender連接濾波器:繞組匝數(shù)可以調(diào)節(jié)的變壓器。在其連接高頻電纜的一側(cè)串接電容器,連接濾波器與耦合電容器共同組成高頻串聯(lián)諧振回路,讓高頻電流順利通過。Connectionfilter:transformerwhosewindingturnscanbeadjusted.

Thecapacitorisconnectedinseriesonthesideofthehigh-frequencycable,andthefilterandthecouplingcapacitorareconnectedtogethertoformahigh-frequencyseriesresonantloop,sothatthehigh-frequencycurrentcanpasssmoothly.ReceiverReceiverSenderSender高頻電纜:用來連接高頻收、發(fā)信機與連接濾波器。Highfrequencycable:usedtoconnectthehighfrequencyreceiverandtransmitterwiththeconnectionfilter.SenderSenderReceiverReceiver在檢查調(diào)試高頻保護時,應將接地刀閘合上,以保證人身安全。放電間隙用以防止過電壓對收、發(fā)信機的傷害。Whencheckinganddebuggingthehighfrequencyprotection,thegroundingswitchshouldbeclosedtoensurepersonalsafety.

Dischargegapisusedtopreventover-voltagedamagetoreceiverandtransmitter.SenderSenderReceiverReceiver收、發(fā)信實際為一體機,收信部分具有放大、解調(diào)接收的高頻信號的作用。Receivingandsendingareactuallyintegratedmachines,andthereceivingparthasthefunctionofamplifyinganddemodulatingthereceivedhigh-frequencysignals.SenderSenderReceiverReceiver啟動方式:Startingmethod故障啟動發(fā)信長時發(fā)信移頻發(fā)信FailuretostartsendingmessagesLonglettersFrequentmovingletter任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

(2)高頻信號與高頻電流關系Relationshipbetweenhighfrequencysignalandhighfrequencycurrent故障啟動方式:電力系統(tǒng)正常運行時收發(fā)信機不發(fā)信,通道中無高頻電流。當電力系統(tǒng)故障時,起動元件啟動收發(fā)信機發(fā)信。Faultstartmode:whenthepowersystemisrunningnormally,thetransceiverdoesnotsendmessages,andthereisnohigh-frequencycurrentinthechannel.

Whenthepowersystemfails,thestarterelementstartsthetransceivertosendmessages.優(yōu)點:對鄰近通道的影響小,可以延長收發(fā)信機的壽命。Advantages:littleimpactonadjacentchannels,canextendtransceiverlife.缺點:必須有啟動元件,且需要定時檢查通道是否良好。Disadvantages:Musthaveastarterelement,andneedstoperiodicallycheckthechannelisgood.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

長期發(fā)信方式:電力系統(tǒng)正常運行時,收發(fā)信機連續(xù)發(fā)信,高頻電流持續(xù)存在,用于監(jiān)視通道是否完好。而高頻電流的消失代表高頻信號。Long-termsendingmode:whenthepowersystemisrunningnormally,thetransceiversendsmessagescontinuouslyandthehigh-frequencycurrentcontinuestoexist,whichisusedtomonitorwhetherthechannelisingoodcondition.

Thedisappearanceofthehighfrequencycurrentrepresentsthehighfrequencysignal.優(yōu)點:通道的工作狀態(tài)受到監(jiān)視,可靠性高。Advantages:theworkingstatusofthechannelismonitored,andthereliabilityishigh.缺點:增大了通道間的干擾,并降低了收發(fā)信機的使用年限。Disadvantages:increasestheinterferencebetweenchannelsandreducestheservicelifeofthetransceiver.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

移頻發(fā)信方式:Movefrequencysignalsendingmode正常運行時發(fā)出頻率的高頻電流,用于監(jiān)視通道。Highfrequencycurrentoffrequencyf2isemittedduringnormaloperationformonitoringchannels.故障時,收發(fā)信機發(fā)出頻率為的高頻電流,頻率為的高頻電流代表高頻信號。Whenafaultoccurs,thetransceiveremitsahigh-frequencycurrentoffrequencyF2,whichrepresentsahigh-frequencysignal.(3)高頻信號的作用

Theroleofhighfrequencysignals任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ProtectiveelmentsProtectiveelmentsSignallockingSignalallowingSignaltrippingTrippingpulseTrippingpulseTrippingpulseProtectiveelments閉鎖信號是阻止保護動作于跳閘的信號。換言之,無閉鎖信號是保護作用于跳閘的必要條件。Thelatchingsignalisasignalthatpreventstheprotectionactionfromtripping.

Inotherwords,non-latchingsignalisanecessaryconditiontoprotectagainsttripping.允許信號是允許保護動作于跳閘的信號。有允許信號是保護動作于跳閘的必要條件。Theallowablesignalisthesignalthatallowstheprotectionactiontotrip.

Permissionsignalisanecessaryconditiontoprotectactionfromtripping.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ProtectiveelmentsProtectiveelmentsProtectiveelmentsTrippingpulseTrippingpulseTrippingpulseSignallockingSignalallowingSignaltripping跳閘信號是直接引起跳閘的信號,收到跳閘信號是跳閘的充要條件。Trippingsignalisthesignalthatdirectlycausestripping,andreceivingthetrippingsignalisanecessaryandsufficientconditionfortripping.3、高頻閉鎖方向保護Highfrequencyblockingdirectionalprotection任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ProtectiveelmentsProtectiveelmentsProtectiveelmentsSignallockingTrippingpulseTrippingpulseTrippingpulseSignalallowingSignaltripping原理:根據(jù)被保護線路兩側(cè)的方向元件分別對短路的方向作出判斷,并利用高頻信號作出綜合判斷,進而決定是否跳閘的一種保護。Principle:accordingtothedirectionelementsonbothsidesoftheprotectedlinetojudgethedirectionoftheshortcircuit,andusethehighfrequencysignaltomakeacomprehensivejudgment,andthendecidewhethertotripaprotection.發(fā)信方式:國內(nèi)廣泛應用的高頻閉鎖方向保護用故障啟動發(fā)信方式,并規(guī)定線路兩端功率由母線指向線路為正方向,由線路指向母線為反方向。Sendingmode:thehighfrequencyblockingdirectionprotectionwhichiswidelyusedinChinausesthefaultstartsendingmode,anditisstipulatedthatthepoweratbothendsofthelinepointstothelinefromthebustothepositivedirection,andthelinepointstothebustothenegativedirection.要求:故障時在啟動元件靈敏度范圍內(nèi)應可靠啟動發(fā)信及啟動保護。Requirement:Incaseoffailure,thetransmitterandprotectionshouldbereliablystartedwithinthesensitivityrangeofthestarterelement.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

方向元件:正向時使高頻收、發(fā)信機停信。反向時,高頻收、發(fā)信機繼續(xù)發(fā)信。Directionelement:tostopthehighfrequencyreceiverandsenderintheforwarddirection.

Inthereversedirection,thehighfrequencyreceiverandtransmittercontinuetosendmessages.電力系統(tǒng)正常運行時,啟動元件不啟動,高頻收、發(fā)信機不發(fā)信,保護不開放。Whenthepowersystemisrunningnormally,thestartingelementdoesnotstart,thehigh-frequencyreceiverandtransmitterdonotsendmessages,andtheprotectionisnotopen.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

StartingelementsPowerdirectionelementWiringdiagramProtectiveblockdiagramTripSenderReceiverChannelForbiddenexitForbiddenexit任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitSenderReceiverTripChannel當BC線路故障時:線路AB、BC上的高頻保護均分別起動發(fā)信。WhentheBClinefails:thehighfrequencyprotectiononlineABandBCstartssendingmessagesrespectively.保護1方向元件判斷正方向,與門有輸出,經(jīng)t2延時使本側(cè)高頻收、發(fā)信機停信,另一方面經(jīng)禁止門2準備出口跳閘。因保護2的方向元件判斷故障為反方向,與門無輸出,高頻收、發(fā)信機連續(xù)發(fā)出高頻信號,閉鎖本側(cè)保護。Theprotection1directionelementjudgesthepositivedirectionandhasanoutputwiththedoor.AftertheT2delay,thehighfrequencyreceiverandsenderatthissidewillstopthemessage.Ontheotherhand,thegate2willpreparetheexittrip.

Becausethefaultofthedirectionelementofprotection2isjudgedtobeintheoppositedirection,andthereisnooutputfromthegate,thehigh-frequencyreceiverandtransmittersendouthigh-frequencysignalscontinuouslytoblocktheprotectionofthelocalside.WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitTripSenderReceiverChannel記憶元件KT1的作用是防止外部故障切除后,近故障點側(cè)的保護啟動元件先返回停止發(fā)信,而遠故障點側(cè)的啟動元件和功率方向元件后返回,造成保護誤動作跳閘。ThefunctionofmemoryelementKT1istopreventtheprotectionstartingelementnearthefaultpointfromreturningtostopsendingaftertheexternalfaultisremoved,whilethestartingelementandpowerdirectionelementatthefarfaultpointreturntostopsendingaftertheexternalfaultisremoved,resultingintheprotectionmisoperationtripping.WiringdiagramStartingelementsPowerdirectionelementProtectiveblockdiagramForbiddenexitForbiddenexitTripSenderReceiverChannel4、相差高頻保護

Differentialhighfrequencyprotection原理:比較被保護線路兩側(cè)電流的相位,即利用高頻信號將電流的相位傳送到對側(cè)去進行比較,稱為相差高頻保護。Principle:Comparethephaseofthecurrentonbothsidesoftheprotectedline,thatis,thephaseofthecurrentistransmittedtotheoppositesidebyusingthehighfrequencysignalforcomparison,whichiscalledthephasedifferencehighfrequencyprotection.假設:線路兩側(cè)的電勢同相,系統(tǒng)各元件的阻抗角相同(實際上有差別的)。Assumption:thepotentialonbothsidesofthelineisinthesamephase,andtheimpedanceAngleofeachelementinthesystemisthesame(actuallythereisadifference).任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ProtectionProtectionThesamephaseReverse,180degreesoutofphase為實現(xiàn)比相,須把線路對端的電流的信號傳送到本端且能代表原工頻電流的相位,由比相系統(tǒng)給出比較結(jié)果。Inordertorealizethephasecomparison,thecurrentsignaloftheoppositeendofthelinemustbetransmittedtothisendandcanrepresentthephaseoftheoriginalworkingfrequencycurrent.Thecomparisonresultisgivenbythephasecomparisonsystem.若兩側(cè)電流相位差近于0°時,保護判斷為被保護范圍內(nèi)部故障,應瞬時動作切除故障。Ifthephasedifferencebetweenthetwosidesofthecurrentiscloseto0°,theprotectionisjudgedtobeaninternalfaultwithintheprotectedrange,andthefaultshouldberemovedbyinstantaneousaction.若兩側(cè)流相位差接近于180°時,保護判斷為外部故障,應可靠將保護閉鎖。Ifthephasedifferencebetweenthetwosidesoftheflowiscloseto180°,theprotectionisjudgedtobeanexternalfault,andtheprotectionshouldbereliablylocked.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

當短路電流為正半周時,高頻發(fā)信機發(fā)出高頻信號,而在負半周時則不發(fā)出信號。Whentheshortcircuitcurrentispositivehalfcycle,thehighfrequencytransmittersendsoutthehighfrequencysignal,butdoesnotsendoutthesignalatthenegativehalfcycle.當被保護范圍內(nèi)部故障時,由于兩側(cè)同時發(fā)出高頻信號,也同時停止發(fā)信。在兩側(cè)收信機收到的高頻信號是間斷的。Whenthefaultoccurswithintheprotectedrange,thetransmissionstopsatthesametimebecausebothsidessendouthighfrequencysignals.

Thehighfrequencysignalsreceivedbythereceiversonbothsidesareintermittent.

當被保護范圍外部故障時,由于兩側(cè)電流相位相差180°,線路兩側(cè)的發(fā)信機交替工作,收信機收到的高頻信號是連續(xù)的高頻信號。Whenthefaultoccursoutsidetheprotectedrange,duetothecurrentphasedifferenceof180°onbothsides,thetransmitteronbothsidesofthelineworksalternatively,andthehigh-frequencysignalreceivedbythereceiveriscontinuoushigh-frequencysignal.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

CurrentwaveformonbothsideshighfrequencysignalonMsidehighfrequencysignalonNsideThehighfrequencysignalreceivedbythereceiveronbothsides結(jié)論:(區(qū)內(nèi)故障)兩側(cè)收信機收到的高頻信號重疊約10ms,保護瞬時動作跳閘。即使內(nèi)部故障時高頻通道遭破壞,不能傳送高頻信號,但收信機仍能收到本側(cè)發(fā)信機發(fā)出的間斷高頻信號,因而不會影響保護跳閘。Conclusion:thehighfrequencysignalreceivedbybothsidesofthereceiveroverlapsabout10ms,whichprotectstheinstantaneousactiontrip.

Evenifthehighfrequencychannelisdestroyedandthehighfrequencysignalcannotbetransmittedduringtheinternalfault,thereceivercanstillreceivetheintermittenthighfrequencysignalsentbythetransmitteronitsside,sotheprotectiontripwillnotbeaffected.保護區(qū)外故障:兩側(cè)的收信機收到的高頻信號是連續(xù)的,線路兩側(cè)的高頻信號互為閉鎖,使兩側(cè)保護不能跳閘。Faultoutsidetheprotectionzone:thehigh-frequencysignalsreceivedbythereceiversonbothsidesofthelinearecontinuous,andthehigh-frequencysignalsonbothsidesofthelineblockeachother,sothattheprotectiononbothsidescannottrip.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

小結(jié):1)高頻閉鎖方向保護是比較線路兩側(cè)功率方向,兩側(cè)均為正方向時保護動作;有一側(cè)為反方向時,閉鎖保護。Summary:1)Highfrequencyblockingdirectionalprotectionisaprotectionactionwhenthepowerdirectionsonbothsidesofthelinearecomparedandbothsidesareinpositivedirections;

Whenonesideisintheoppositedirection,lockprotection.2)相差高頻保護是比較線路兩側(cè)電流的相位,相位相近時保護動作;反相時保護閉鎖。Differencehighfrequencyprotectionistocomparethephaseofthecurrentonbothsidesoftheline,theprotectionactionwhenthephaseisclose;

Protectionlatchduringphasereversal.發(fā)信方式:故障發(fā)信、長期發(fā)信、移頻發(fā)信。Sendingmode:faultsending,long-termsending,movingfrequentsending.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

高頻信號:跳閘信號、允許信號、閉鎖信號。Highfrequencysignal:trippingsignal,allowingsignal,blockingsignal.高頻電流與高頻信號關系:長期發(fā)信,高頻電流消失代表高頻信號。故障發(fā)信,高頻電流代表高頻信號。Therelationshipbetweenhighfrequencycurrentandhighfrequencysignal:sendingsignalsforalongtime,thedisappearanceofhighfrequencycurrentrepresentsthehighfrequencysignal.

Faultsending,highfrequencycurrentrepresentshighfrequencysignal.移頻信號:高頻電流代表高頻信號。Frequencyshiftsignal:thehighfrequencycurrentrepresentsthehighfrequencysignalf2.任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

光纖通道容量大、抗腐蝕、敷設及檢修方便,可節(jié)省大量有色金屬;可解決縱聯(lián)保護中導引線保護及高頻保護的通道易受電磁干擾、高頻信號衰耗等問題。Thefiberchannelhaslargecapacity,corrosionresistance,convenientlayingandmaintenance,andcansavealotofnon-ferrousmetals.

Itcansolvetheproblemssuchaselectromagneticinterferenceandhighfrequencysignaldecayinthechannelofthelongitudinalprotectionandhighfrequencyprotection.1.架空地線復合光纜(OPGW)的結(jié)構(gòu)、特征Structureandcharacteristicsofoverheadgroundcompositeopticalcable(OPGW)任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

復合光纜地線具有2種功能,一是作為輸電線路的避雷線;二是通過復合在地線中的光纖,是傳送光信號的介質(zhì),可傳送音頻、視頻、數(shù)據(jù)和各種控制信號,組建多路寬帶通信網(wǎng)。Thegroundwireofcompositeopticalcablehastwofunctions.Oneisasalightningconductorfortransmissionlines.

Thesecondisthroughthecompositeopticalfiberintheground,isthetransmissionofopticalsignalmedium,cantransmitaudio,video,dataandavarietyofcontrolsignals,theformationofamulti-channelbroadbandcommunicationnetwork.

2.光纖通信的特點

Characteristicsofopticalfibercommunication1)通信容量大。Largecommunicationcapacity.2)節(jié)約大量金屬材料Savealotofmetalmaterials任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

3)光纖通信還有保密性好,敷設方便,不怕雷擊,不受外界電磁干擾,抗腐蝕和不怕潮等優(yōu)點。Fiberopticcommunicationalsohastheadvantagesofgoodconfidentiality,convenientlaying,notafraidoflightningstrike,notaffectedbyexternalelectromagneticinterference,corrosionresistanceandnotafraidofmoisture.

4)光纖最重要的特性之一是無感應性能,因此利用光纖可以構(gòu)成無電磁感應的、極為可靠的通道。Oneofthemostimportantcharacteristicsofopticalfiberisthenon-inductionperformance,sotheuseofopticalfibercanbeconstructedwithoutelectromagneticinduction,extremelyreliablechannel.3、光纖保護的組成

Compositionofopticalfiberprotection任務二輸電線路高頻保護Task2HighFrequencyProtectioninTransmissionLine

ElectricparametersElectricparametersElectricparametersElectricparametersRelayprotectionRelayprotectionmodulatormodulatormodemmodemPCMtransmitterjointPCMtransmitterjointOpticalcablereceiverOpticalcablereceiverOpticalcablereceiverOpticalcablereceiverOpticaltransceiverOpticaltransceiverMovableconnectorFiberopticcableMovableconnectorMovableconnector由故障判別元件(繼電保護部分)和信號傳輸系統(tǒng)(PCM端機、光端機以及光纜通道)組成Itiscomposedoffaultidentificationelement(relayprotectionpart)andsignaltransmissionsystem(PCMterminal,opticalterminalandopticalcablechannel)PCM端機由PCM調(diào)制器和PCM解調(diào)器組成。PCM(PulseCodeModulation)調(diào)制器的原理是脈沖編碼調(diào)制。PCMterminalconsistsofaPCMmodulatorandaPCMdemodulator.APCM(PulseCodeModulation)modulatorisbasedonPulseCodeModulation.ElectricparametersElectricparametersRelayprotectionRelayprotectionmodulatormodulatormodemmodemPCMtransmitterPCMtransmitterOpticalcablesenderOpticalcablesenderOpticaltr

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