軌道電路認知天津鐵道職業技術學院鐵路信號基礎設備維護4.1

軌道電路認知軌道電路是鐵路信號自動控制的基礎設備，它的性能直接影響行車安全和運輸效率，是鐵路信號的重要基礎設備。軌道電路是以鐵路線路的兩根鋼軌作為導體，兩端加以電氣絕緣或電氣分割，并用引接線連接信號電源和接收設備所構成的電氣回路。利用軌道電路可以自動檢測列車、車輛的位置，控制信號機的顯示；將地面信號傳遞給機車，控制列車運行，保證行車安全。4.1

CognitionoftrackcircuitTrackcircuitisthebasicequipmentforautomaticcontrolofrailwaysignalwhichperformancedirectlyaffectsthetrainrunningsafetyandtransportationefficiency,anditisanimportantbasicequipmentfortherailwaysignal.Trackcircuitisanelectricalcircuitconsistingoftworailsofarailwaylineasconductors,electricallyinsulatedordividedatbothends,andanelectricalcircuitconnectingsignaltransmittingandreceivingequipmentwithleadwire.Thetrackcircuitcanautomaticallydetectthepositionoftrainsandvehicles,controlthedisplayofthesignal;passthegroundsignaltothelocomotive,andcontrolthetrainoperationtoensuredrivingsafety.4.1

軌道電路認知

軌道電路通常是由鋼軌線路、鋼軌絕緣、送電設備、受電設備等組成，最基本的軌道電路如圖4-1所示。4.1

Cognitionoftrackcircuit

1.CompositionoftrackcircuitsThetrackcircuitisusuallycomposedoftrack,trackinsulation,powertransmissionequipmentandreceivingequipmentetc.ConnectionlineTrackinsulationPowersupplyTrackPowertransmissionendReceivingendTrackrelayLeadwire4.1

軌道電路認知

1.鋼軌線路鋼軌線路由鋼軌、鋼軌接續線和引接線組成。鋼軌是軌道電路的導體。軌端接續線是為了減少兩條鋼軌接頭處的電阻而增設的連線。引接線是連接軌道電路兩端送電設備和受電設備的導線。2.鋼軌絕緣鋼軌絕緣是鋼軌線路兩端的絕緣裝置，其作用是為分隔相鄰軌道電路而裝，兩絕緣節之間的鋼軌線路稱為軌道電路的長度。3.送電設備主要由電源設備和限流電阻RX組成。限流器有兩個作用：一是保護電源不因電流過載而損壞；二是保證列車占用時，GJ可靠落下。4.受電設備受端的設備通常采用電磁繼電器或電子繼電器，用來接收送電設備經鋼軌傳送的電信號，并控制有關信號設備執行命令，它是軌道電路的執行元件。4.1

Cognitionoftrackcircuit4.ReceivingequipmentThereceivingequipmentusuallyadoptsanelectromagneticrelayoranelectronicrelaytoreceivetheelectricalsignalstransmittedbythepowertransmissionequipmentthroughthetrack,andcontrolstherelevantsignalequipmenttoexecutethecommand,whichistheexecutionelementofthetrackcircuit.4.1

軌道電路認知軌道電路的作用1.監督列車的占用軌道電路的首要作用就是監督列車占用，檢查軌道電路是否完整。利用軌道電路監督列車運行或列車和車輛在車輛段等線路的占用狀態。反映線路的空閑狀況，為開放信號、建立進路或構成閉塞提供依據。2.傳遞行車信息軌道電路作為傳遞信息的通道，如移頻自動閉塞利用軌道電路傳遞不同的頻率信息來反映列車的位置，決定通過信號機的顯示，為列車運行提供行車命令。軌道電路中傳遞的行車信息，還為列車運行自動控制系統直接提供控制列車運行所需的列車位置、前方信號機狀態和線路條件等有關信息，以決定列車運行的目標速度或決定列車運行的目標速度，從而控制列車運行。4.1

Cognitionoftrackcircuit2.Functionoftrackcircuits（1）SuperviseoccupationofthetrainsTheprimaryfunctionofthetrackcircuitistosupervisethetrainoccupationandcheckwhetherthetrackcircuitiscomplete.Trackcircuitisusedtomonitorthetrainrunningoroccupancyoftrainsandvehiclesonlinessuchasthedepot,reflectthefreeconditionofthelineandprovideabasicfoundationforclearsignal,operatearouteorformablock.4.1

Cognitionoftrackcircuit2.Functionoftrackcircuits（2）DelivertrainrunninginformationThetrackcircuitactsasachanneltotransmitinformation,forexample,frequencyshiftautomaticblockusesthetrackcircuittodeliverdifferentfrequencyinformationtoreflectthepositionofthetrain,anddeterminesdisplayofthesignalthustoprovidetherunningcommandforthetrain.Thetrainrunninginformationtransmittedinthetrackcircuitalsodirectlyprovidesthetrainoperationautomaticcontrolsystemwiththerelevantinformationaboutthetrainposition,thefrontsignalstateandthelineconditionofthetrainoperation,soastodeterminethetargetspeedofthetrainoperationthustocontrolthetrainoperation.4.1

軌道電路認知軌道電路的基本原理當軌道電路內鋼軌完整，且沒有列車占用時，如圖4-2所示，電流經過軌道繼電器，GJ↑，表示軌道電路空閑。4.1

Cognitionoftrackcircuit3.Basicprincipleoftrackcircuits(1)NotrainoccupiesthetrackcircuitWhenthetrackinthetrackcircuitiscompleteandunoccupied,thecurrentpassesthroughtrackrelay,andGJ↑,indicatingthatthetrackcircuitisfree.4.1

軌道電路認知軌道電路的基本原理有車占用當軌道電路被列車占用時，如圖4-3所示，電流被列車輪對分流，流經軌道繼電器的電流大大減小，GJ↓落下，表示軌道電路被占用。4.1

Cognitionoftrackcircuit3.Basicprincipleoftrackcircuits

(2)TrainoccupiesthetrackcircuitWhenthetrackcircuitisoccupiedbyatrain,thecurrentisshuntedbythetrainwheel,thecurrentflowingthroughthetrackrelayisgreatlyreduced,andGJ↓falls,indicatingthatthetrackcircuitisoccupied.wheelpair4.1

軌道電路認知4.軌道電路的分類1.按供電電源分類軌道電路可分為直流軌道電路和交流軌道電路。采用直流電源的軌道電路，稱為直流軌道電路。采用交流供電的軌道電路，稱為交流軌道電路，它是最常用的軌道電路類型。2.按工作方式分為：軌道電路可分為開路式軌道電路和閉路式軌道電路。（1）開路式軌道電路，平時呈開路狀態，不構成回路，軌道繼電器落下GJ↓。有車占用時，軌對構成回路，軌道繼電器吸起。（2）閉路式軌道電路，平時構成閉合回路，軌道繼電器吸起GJ↑。有車占用時，因車輪分路，軌道繼電器落下。4.1

Cognitionoftrackcircuit4.ClassificationoftrackcircuitsTrackcircuitisclassifiedbypowersupply

Accordingtothepowersupply,trackcircuitcanbedividedintoDCtrackcircuitandACtrackcircuit.AtrackcircuitusingaDCpowersupplyiscalledaDCtrackcircuit.ThetrackcircuitusingACpowerisknownasACtrackcircuit,whichisthemostcommonlyusedtypeoftrackcircuit.4.1

Cognitionoftrackcircuit2.Trackcircuitisclassifiedbyworkingmode(1)OpentrackcircuitAccordingtoworkingmode,trackcircuitcanbedividedintoopencircuittrackcircuitandclosedcircuittrackcircuit.Opentrackcircuitusuallyshowsopenstate,itdoesnotformacircuit,trackrelayfallsandGJ↓.Whentrackisoccupied,throughthewheelpairitformsaloopandtrackrelayisenergized.4.1

Cognitionoftrackcircuit(2)Closedtrackcircuitusuallyformsaclosedcircuit,andthetrackrelayisenergizedGJ↑.Whenitisoccupiedbytrain,trackrelayfallsbecausethewheelpairshuntedthetrack.4.1

軌道電路認知5.按所處的位置分：（1）區間軌道電路，主要用于自動閉塞區段，不僅要監督各閉塞分區是否空閑，而且要傳輸有關行車信息。（2）站內軌道電路，用于站內各區段，一般只有監督本區段是否空閑的功能，不能發送其他信息。6.按軌道電路內有無道岔分：（1）無岔區段軌道電路，鋼軌線路無分支。如圖4-4所示。（2）道岔區段軌道電路，鋼軌線路有分支，要增加絕緣、道岔連接線和跳線。當分支超過一定長度時，還必須設多個受電端。如圖4-5所示。7.按適用的區段分：（1）非電氣化區段軌道電路，沒有抗電化干擾的特殊要求。（2）電氣化區段軌道電路，既要抗電氣化干擾，又要保證牽引回流的暢通無阻。4.1

Cognitionoftrackcircuit5.Trackcircuitisdividedbyitslocation(1)Thesectiontrackcircuit,whichismainlyusedforautomaticblocksection.Itnotonlysuperviseswhethereachblocksectionisfree,butalsotransmitsrelevanttrafficinformation.(2)Trackcircuitinstationisusedfordifferentsectionsinstations,usuallyitonlyhasthefunctionofsupervisingwhetherthesectionisfreeornot,itcan’tsendotherinformation.4.1

Cognitionoftrackcircuit6.Thetrackcircuitisdividedbyturnouts(1)No-turnout-sectiontrackcircuit,tracklinehasnobranch.(2)Turnoutsectiontrackcircuit,raillinehasbranches,turnoutconnectionlineandjumpershavetobeadded.Whenthebranchexceedsacertainlength,multiplereceivingterminalsmustalsobeprovided.4.1

Cognitionoftrackcircuit7.Thetrackcircuitisdividedbytheapplicationsection(1)Trackcircuitinnon-electrifiedsection,itdoesnothavespecialrequirementsofanti-electrifiedinterference.(2)Trackcircuitinelectrifiedsection,itdoesnothavetoconsideranti-electrifiedinterference,butalsohavetoensurethesmoothflowoftractioncurrent.4.1

軌道電路認知5.站內軌道電路的劃分和命名1.軌道電路的劃分站內軌道電路區段的劃分，首先要保證軌道電路的可靠工作，并應滿足排列平行進路和不影響作業效率為原則。電氣集中或計算機聯鎖車站，凡有信號機防護的進路中道岔區段與股道，以及信號機的接近區段，均應裝設軌道電路，用以反映進路和接近區段內是否空閑和車輛所在的位置，并滿足提高站內作業效率的要求，站內軌道電路的具體劃分原則有以下幾點：（1）有信號機的地方必須設置絕緣節：信號機前后應劃分成不同的區段，凡有信號機的地方均設有軌道絕緣，其前后為兩個不同的軌道電路區段。（2）為了滿足行車、調車作業效率的提高，凡能平行運行的進路，其間應設軌道絕緣隔開，渡線上的絕緣，以及能構成平行進路的前后道岔，中間都應裝設軌道絕緣。4.1

Cognitionoftrackcircuit5.Divisionandnamingoftrackcircuitswithinthestation1.DivisionoftrackcircuitsThedivisionoftrackcircuitsinthestationshouldfirstensurethereliableworkofthetrackcircuit,andmeettheprincipleofarrangingparallelcircuitsandnotaffectingtheoperationefficiency.Inelectricinterlockingorcomputerinterlockingstation,turnoutsectionandtrackwhichlocatesaroutewhichisprotectedbysignalandtheapproachsectionofthesignalshallbeequippedwithtrackcircuitstoreflectwhethertherouteisfreeorthepositionofvehiclesinapproachsection,andmeettherequirementsofimprovingtheoperationefficiencyofthestation.4.1

CognitionoftrackcircuitThedivisionprinciplesoftrackcircuitsinthestationhasthefollowingpointsindetail:(1)Insulatedtrackjointhastobesetwhenthereisasignal,thefrontandrearofsignalsshallbedividedintodifferentsections,wherethereisasignalthereshallbeprovidedwithtrackinsulation,thefrontandrearofitshouldbetwodifferenttrackcircuits.D1protectsthesectionD1doesnotprotect4.1

Cognitionoftrackcircuit(2)Inordertomeettheimprovementoftrainoperationandshuntingoperationefficiency,thetrackinsulationshallbeprovidedinparallelroutes,theinsulationonthecrossingline,andthefrontandrearturnoutthatcanformtheparallelrouteshallbeprovidedtheinsulationinthemiddle.4.1

軌道電路認知（3）為了提高行車、調車的作業效率，在車站上，有時為了使列車通過道岔后及時使道岔解鎖，要將軌道電路區段劃短，以提高咽喉通過能力。（4）每一道岔區段的軌道電路內所包括的道岔數不得超過三組。（5）集中區與非集中區分界處信號機外方有應劃分一段軌道電路作為信號機的接近區段。4.1

Cognitionoftrackcircuit(3)Inordertoimprovetheefficiencyoftrainoperationandshunting,sometimesatstationstounlocktheturnoutafterthetrainpassesthroughtheturnout,thetrackcircuitsectionshouldbecutshorttoimprovethethroatpassingability.(4)Thenumberofturnoutsincludedinaturnoutsectionshallnotexceedthreegroups.(5)Attheoutsideofthesignalwhichlocatesattheboundaryofcentralizedareaandnon-centralizedarea,atrackcircuitshallbedividedastheapproachsectionofthesignal.4.1

軌道電路認知2.站內軌道電路的命名（1）道岔區段根據道岔編號命名。如果這個區段就一個道岔，它的命名就是道岔編號1DG；如果有兩個道岔，它的命名就是小號道岔編號—大號道岔編號，如3-5DG；如果有三組道岔，它的命名就是小號道岔編號—大號道岔編號，中間道岔不寫，如7-11DG。（2）無岔區段①股道：以股道號命名，如：IG、3G；②進站信號機內方無岔區段：根據所銜接的股道編號加咽喉來表示，如下行咽喉用“A”，如、IAG、IIAG；上行咽喉用“B”，如IG、IIBG。③差置調車信號機之間的無岔區段：以兩端相鄰的道岔編號寫成分數形式來表示，用最小道岔編號和最大道岔編號，中間用斜杠分開加WG。如：1/3WG。4.1

Cognitionoftrackcircuit2.Nameofthetrackcircuitwithinthestation(1)TurnoutsectionTurnoutsectionisnamedaccordingtotheturnoutNo.Ifthereisoneturnoutinthesection,itsnameisturnoutnumber,forexample1DG;iftherearetwoturnouts,itisnamedbysmallturnoutnumbertolargeturnoutnumber,suchas5-9DG;iftherearethreeturnouts,itisnamedbysmallturnoutnumber-largeturnoutnumber,themiddleturnoutisnotwritten,suchas4-12DG.4.1

Cognitionoftrackcircuit(2)No-turnoutsection①Trackisnamedasthetracknumber,suchas:IG,3G;②No-turnout-sectioninsidethehomesignal:Accordingtotheconnectingtracknumberandthroat,downthroatis"A",suchas,IAG,IIAG;upsidethroatis"B",schasIG,IIBG.4.1

Cognitionoftrackcircuit③No-turnoutsectionbetweendifferentialshuntingsignals:writteninfractionwithadjacentturnoutnumbersatbothends,withminimumturnoutnumberandmaximumturnoutnumber,andplusWG.Forexample,1/19WG.4.1

軌道電路認知軌道電路的基本參數1.對軌道電路影響最大的三個參數（1）道床電阻也稱道碴電阻，指每公里長度的軌道電路中，兩根軌條間的漏泄電阻。通過鋼軌的電流有一部分要通過枕木、道砟和大地形成泄漏，這種泄漏情況極不穩定。泄漏電流是由一根鋼軌經軌枕和道床流往另一根鋼軌，其大小由鋼軌線路的絕緣阻抗，即道床電阻決定。道床電阻的大小，一方面取決于道床的材料、道床層的厚度，軌枕的材質和數量；另一方面還取決于溫度、濕度的變化，以及道床土壤的導電率等因素。（2）鋼軌阻抗鋼軌阻抗指當軌道電路中通以電流，每公里長度的兩根鋼軌所存在的阻抗。包括軌條本身的阻抗和鋼軌連接處的阻抗。前者對一定頻率的電流來說是固定不變的，后者主要由魚尾板、鋼軌接續線和他們的接觸電阻形成。4.1

CognitionoftrackcircuitBasicparametersoftrackcircuits1.RoadbedresistanceRoadbedresistanceisalsocalledballastresistance,referstotheleakageresistancebetweentwotrackperkilometerlength.Partofthecurrentthroughtherailistoleakthroughsleepers,ballastandearth,whichisextremelyunstable.Theleakagecurrentisfromarailthroughthesleeperandroadbedtoanother,whichamountisdeterminedbytheinsulationimpedanceoftherailline,thatistheroadbedresistance.4.1

CognitionoftrackcircuitBasicparametersoftrackcircuits1.RoadbedresistanceTheamountoftheroadbedresistancedependsonthematerialandthicknessoftheroadbed,thematerialofsleeperandquantityofsleepers,andalsothechangeoftemperatureandhumidityandtheconductivityoftheroadbedsoil.4.1

CognitionoftrackcircuitBasicparametersoftrackcircuits2.RailimpedanceRailimpedancereferstotheimpedanceoftworailsperkilometerlengthflowingthroughcurrent.Itincludestheimpedanceoftherailitselfandtheimpedanceattherailconnection.Theformerisfixedforacertainfrequencyofcurrent,andthelatterismainlyformedbythecontactresistancemadeupoffishtailplatesandrailconnections.4.1

軌道電路認知（3）電源電壓電源電壓指軌道電路送電端的發送電壓。電源電壓過大或過小都會對軌道電路造成影響。2.軌道電路分路靈敏度（1）列車分路電阻列車占用軌道電路時，列車輪對跨接在軌道電路的兩根鋼軌上構成軌道分路，這個分路的輪軸電阻就是列車分路電阻。它是由車輪和輪軸本身的電阻和輪緣與鋼軌頭部表面的接觸電阻組成，由于輪緣與鋼軌頭部表面的接觸電阻很小，因此車輪和車軸形成的電阻比接觸電阻小很多，可以忽略不計。列車分路電阻與鋼軌上分路的車軸數、車輛的載重情況、列車的行駛速度、輪緣裝配質量、鋼軌表面的潔凈程度、是否生銹，有無撒沙及其它油質化學絕緣層等因素均有關系，它的變化范圍很大，可以從千分之幾歐變化到0.06?。4.1

CognitionoftrackcircuitBasicparametersoftrackcircuits

3.PowersupplyvoltagePowersupplyvoltagereferstothetransmissionvoltageatthepowersupplyendofthetrackcircuit.Thepowersupplyvoltagecanaffectthetrackcircuitifitistoobigortoosmall.4.1

CognitionoftrackcircuitShuntingsensitivityoftrackcircuit1.TrainshuntingresistanceWhenthetrainoccupiesthetrackcircuit,thewheelpairrunsacrossthetwotracksofthetrackcircuit.Theaxialresistanceisthetrainshuntingresistance.Itiscomposedoftheresistanceofthewheelandtheaxleitselfandthecontactresistanceoftherimandtheheadsurfaceoftherail.Sincethesmallcontactresistanceoftheheadsurfaceofthewheelandaxleismuchlessandnegligiblethanthecontactresistance.Theshuntingresistanceofthetrainisrelatedtothenumberofaxlesontherail,theload,thetrainspeed,rimassemblyquality,cleanlinessofrailsurface,rust,sandandotheroilchemicalinsulation.Itschangerangeisverylargeandcanchangefromtensofathousandohmto0.06Ω.4.1

軌道電路認知（2）分路靈敏度當軌道電路被列車車輪或其它導體分路，恰好使軌道電路繼電器線圈電流減少到落下值時的列車分路電阻值（或導體的電阻值）就是該軌道電路的分路靈敏度。（3）極限分路靈敏度在軌道電路上各點的分路靈敏度不同，對于某一具體軌道電路來說，它的分路靈敏度應該以最小的分路靈敏度為準，稱為極限分路靈敏度。（4）標準分路靈敏度我國現行規定標準分路靈敏度為0.06?，是和國際上規定的分路靈敏度是一致的。任何軌道電路在分路狀最不利的條件下，用0.06?電阻進行分路時，軌道繼電器應釋放銜鐵（連續式軌道電路）或不吸起（脈沖式）。否則不能保證分路狀態的可靠工作。4.1

CognitionoftrackcircuitShuntingsensitivityoftrackcircuit

2.ShuntingsensitivityWhenthetrackcircuitisshuntedbythetrainwheelorotherconductor,theresistancevalue(orconductorresistance)justmakerelayreducedtode-energizedisthecalledshuntingsensitivityofthetrackcircuit.wheelpair4.1

CognitionoftrackcircuitShuntingsensitivityoftrackcircuit3.

LimitshuntingsensitivityTheshuntingsensitivityoftrackcircuitsfordifferentpointisdifferent,foraspecifictrackcircuit,itsshuntingsensitivityshouldbetheminimum,whichiscalledthelimitshuntingsensitivity.4.StandardshuntingsensitivityThecurrentChinesestandardshuntingsensitivityof0.06Ω,whichisconsistentwiththeinternationalshuntingsensitivity.foranytrackcircuit,undertheworstcondition,shuntedwith0.06Ωresistance,trackrelayshallreleasearmature(forcontinuoustrackcircuit.)ordoesnotenergize(pulse).Otherwise,thereliableworkofshuntedstatecannotbeguaranteed.4.1

軌道電路認知軌道電路的基本工作狀態1.調整狀態調整狀態指軌道電路完整和空閑、接收設備（例如軌道繼電器）正常工作的狀態。在調整狀態，對于軌道繼電器來說，它從鋼軌上接收到的電流越大，它的工作就越可靠。但這個電流值將隨著道床電阻、鋼軌阻抗、發送電壓的變化而變化。調整狀態的最不利條件是：發送電壓最低、道床電阻最小、鋼軌阻抗最大，同時軌道電路長度為極限長度。在調整狀態最不利因素下，軌道繼電器應能可靠地工作，反映軌道電路的空閑狀態。2.分路狀態分路狀態指當軌道電路區段有列車占用時，接收設備被輪對分路而停止工作的狀態。分路狀態的最不利條件是：發送電壓最高、道床電阻最大、鋼軌阻抗最小、列車分路電阻最大。在分路狀態的最不利因素下，軌道電路接收設備應能可靠地停止工作，反映軌道電路區段有車占用。4.1

CognitionoftrackcircuitBasicworkingstatesoftrackcircuits1.RegulatedstateTheregulatedstatereferstothestatewherethetrackcircuitiscompleteandfree,andthereceivingequipment(e.g.,thetrackrelay)worksnormally.4.1

CognitionoftrackcircuitBasicworkingstatesoftrackcircuits1.RegulatedstateUndertheregulatedstate,forthetrackrelay,thegreatercurrentitreceivesfromtherail,themorereliableitworks.Butthiscurrentvaluewillchangewiththeroadbedresistance,railimpedance,andtransmissionvoltage.Theworstconditionsforregulatedstatearetheminimumtransmissionvoltage,minimumroadbedresistance,maximumrailimpedance,andthetrackcircuitlengthisthelimitlength.Undertheworststateofregulatedstate,trackrelayshallworkreliablyandreflectthefreestateofthetrackcircuit.4.1

CognitionoftrackcircuitBasicworkingstatesoftrackcircuits2.ShuntedstateTheshuntedstatereferstothestateinwhichthereceivingequipmentstopsworkingwhenthetrackcircuitsectionisoccupiedbythewheelpair.4.1

CognitionoftrackcircuitBasicworkingstatesoftrackcircuits2.ShuntedstateTheworstconditionsofshuntedstatearethehighesttransmissionvoltage,maximumroadbedresistance,minimumrailimpedance,andmaximumtrainshuntedresistance.Undertheworstfactorsofshuntedstate,thetrackcircuitreceivingequipmentshallrel