轨道电路认知铁路信号基础设备维护课件

轨道电路认知天津铁道职业技术学院铁路信号基础设备维护4.1

轨道电路认知轨道电路是铁路信号自动控制的基础设备，它的性能直接影响行车安全和运输效率，是铁路信号的重要基础设备。轨道电路是以铁路线路的两根钢轨作为导体，两端加以电气绝缘或电气分割，并用引接线连接信号电源和接收设备所构成的电气回路。利用轨道电路可以自动检测列车、车辆的位置，控制信号机的显示；将地面信号传递给机车，控制列车运行，保证行车安全。4.1

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

轨道电路认知

轨道电路通常是由钢轨线路、钢轨绝缘、送电设备、受电设备等组成，最基本的轨道电路如图4-1所示。4.1

Cognitionoftrackcircuit

1.CompositionoftrackcircuitsThetrackcircuitisusuallycomposedoftrack,trackinsulation,powertransmissionequipmentandreceivingequipmentetc.ConnectionlineTrackinsulationPowersupplyTrackPowertransmissionendReceivingendTrackrelayLeadwire4.1

轨道电路认知

1.钢轨线路钢轨线路由钢轨、钢轨接续线和引接线组成。钢轨是轨道电路的导体。轨端接续线是为了减少两条钢轨接头处的电阻而增设的连线。引接线是连接轨道电路两端送电设备和受电设备的导线。2.钢轨绝缘钢轨绝缘是钢轨线路两端的绝缘装置，其作用是为分隔相邻轨道电路而装，两绝缘节之间的钢轨线路称为轨道电路的长度。3.送电设备主要由电源设备和限流电阻RX组成。限流器有两个作用：一是保护电源不因电流过载而损坏；二是保证列车占用时，GJ可靠落下。4.受电设备受端的设备通常采用电磁继电器或电子继电器，用来接收送电设备经钢轨传送的电信号，并控制有关信号设备执行命令，它是轨道电路的执行元件。4.1

Cognitionoftrackcircuit4.ReceivingequipmentThereceivingequipmentusuallyadoptsanelectromagneticrelayoranelectronicrelaytoreceivetheelectricalsignalstransmittedbythepowertransmissionequipmentthroughthetrack,andcontrolstherelevantsignalequipmenttoexecutethecommand,whichistheexecutionelementofthetrackcircuit.4.1

轨道电路认知轨道电路的作用1.监督列车的占用轨道电路的首要作用就是监督列车占用，检查轨道电路是否完整。利用轨道电路监督列车运行或列车和车辆在车辆段等线路的占用状态。反映线路的空闲状况，为开放信号、建立进路或构成闭塞提供依据。2.传递行车信息轨道电路作为传递信息的通道，如移频自动闭塞利用轨道电路传递不同的频率信息来反映列车的位置，决定通过信号机的显示，为列车运行提供行车命令。轨道电路中传递的行车信息，还为列车运行自动控制系统直接提供控制列车运行所需的列车位置、前方信号机状态和线路条件等有关信息，以决定列车运行的目标速度或决定列车运行的目标速度，从而控制列车运行。4.1

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

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

轨道电路认知轨道电路的基本原理当轨道电路内钢轨完整，且没有列车占用时，如图4-2所示，电流经过轨道继电器，GJ↑，表示轨道电路空闲。4.1

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

轨道电路认知轨道电路的基本原理有车占用当轨道电路被列车占用时，如图4-3所示，电流被列车轮对分流，流经轨道继电器的电流大大减小，GJ↓落下，表示轨道电路被占用。4.1

Cognitionoftrackcircuit3.Basicprincipleoftrackcircuits

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

轨道电路认知4.轨道电路的分类1.按供电电源分类轨道电路可分为直流轨道电路和交流轨道电路。采用直流电源的轨道电路，称为直流轨道电路。采用交流供电的轨道电路，称为交流轨道电路，它是最常用的轨道电路类型。2.按工作方式分为：轨道电路可分为开路式轨道电路和闭路式轨道电路。（1）开路式轨道电路，平时呈开路状态，不构成回路，轨道继电器落下GJ↓。有车占用时，轨对构成回路，轨道继电器吸起。（2）闭路式轨道电路，平时构成闭合回路，轨道继电器吸起GJ↑。有车占用时，因车轮分路，轨道继电器落下。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

轨道电路认知5.按所处的位置分：（1）区间轨道电路，主要用于自动闭塞区段，不仅要监督各闭塞分区是否空闲，而且要传输有关行车信息。（2）站内轨道电路，用于站内各区段，一般只有监督本区段是否空闲的功能，不能发送其他信息。6.按轨道电路内有无道岔分：（1）无岔区段轨道电路，钢轨线路无分支。如图4-4所示。（2）道岔区段轨道电路，钢轨线路有分支，要增加绝缘、道岔连接线和跳线。当分支超过一定长度时，还必须设多个受电端。如图4-5所示。7.按适用的区段分：（1）非电气化区段轨道电路，没有抗电化干扰的特殊要求。（2）电气化区段轨道电路，既要抗电气化干扰，又要保证牵引回流的畅通无阻。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

轨道电路认知5.站内轨道电路的划分和命名1.轨道电路的划分站内轨道电路区段的划分，首先要保证轨道电路的可靠工作，并应满足排列平行进路和不影响作业效率为原则。电气集中或计算机联锁车站，凡有信号机防护的进路中道岔区段与股道，以及信号机的接近区段，均应装设轨道电路，用以反映进路和接近区段内是否空闲和车辆所在的位置，并满足提高站内作业效率的要求，站内轨道电路的具体划分原则有以下几点：（1）有信号机的地方必须设置绝缘节：信号机前后应划分成不同的区段，凡有信号机的地方均设有轨道绝缘，其前后为两个不同的轨道电路区段。（2）为了满足行车、调车作业效率的提高，凡能平行运行的进路，其间应设轨道绝缘隔开，渡线上的绝缘，以及能构成平行进路的前后道岔，中间都应装设轨道绝缘。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

轨道电路认知（3）为了提高行车、调车的作业效率，在车站上，有时为了使列车通过道岔后及时使道岔解锁，要将轨道电路区段划短，以提高咽喉通过能力。（4）每一道岔区段的轨道电路内所包括的道岔数不得超过三组。（5）集中区与非集中区分界处信号机外方有应划分一段轨道电路作为信号机的接近区段。4.1

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

轨道电路认知2.站内轨道电路的命名（1）道岔区段根据道岔编号命名。如果这个区段就一个道岔，它的命名就是道岔编号1DG；如果有两个道岔，它的命名就是小号道岔编号—大号道岔编号，如3-5DG；如果有三组道岔，它的命名就是小号道岔编号—大号道岔编号，中间道岔不写，如7-11DG。（2）无岔区段①股道：以股道号命名，如：IG、3G；②进站信号机内方无岔区段：根据所衔接的股道编号加咽喉来表示，如下行咽喉用“A”，如、IAG、IIAG；上行咽喉用“B”，如IG、IIBG。③差置调车信号机之间的无岔区段：以两端相邻的道岔编号写成分数形式来表示，用最小道岔编号和最大道岔编号，中间用斜杠分开加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

轨道电路认知轨道电路的基本参数1.对轨道电路影响最大的三个参数（1）道床电阻也称道碴电阻，指每公里长度的轨道电路中，两根轨条间的漏泄电阻。通过钢轨的电流有一部分要通过枕木、道砟和大地形成泄漏，这种泄漏情况极不稳定。泄漏电流是由一根钢轨经轨枕和道床流往另一根钢轨，其大小由钢轨线路的绝缘阻抗，即道床电阻决定。道床电阻的大小，一方面取决于道床的材料、道床层的厚度，轨枕的材质和数量；另一方面还取决于温度、湿度的变化，以及道床土壤的导电率等因素。（2）钢轨阻抗钢轨阻抗指当轨道电路中通以电流，每公里长度的两根钢轨所存在的阻抗。包括轨条本身的阻抗和钢轨连接处的阻抗。前者对一定频率的电流来说是固定不变的，后者主要由鱼尾板、钢轨接续线和他们的接触电阻形成。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

轨道电路认知（3）电源电压电源电压指轨道电路送电端的发送电压。电源电压过大或过小都会对轨道电路造成影响。2.轨道电路分路灵敏度（1）列车分路电阻列车占用轨道电路时，列车轮对跨接在轨道电路的两根钢轨上构成轨道分路，这个分路的轮轴电阻就是列车分路电阻。它是由车轮和轮轴本身的电阻和轮缘与钢轨头部表面的接触电阻组成，由于轮缘与钢轨头部表面的接触电阻很小，因此车轮和车轴形成的电阻比接触电阻小很多，可以忽略不计。列车分路电阻与钢轨上分路的车轴数、车辆的载重情况、列车的行驶速度、轮缘装配质量、钢轨表面的洁净程度、是否生锈，有无撒沙及其它油质化学绝缘层等因素均有关系，它的变化范围很大，可以从千分之几欧变化到0.06Ω。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

轨道电路认知（2）分路灵敏度当轨道电路被列车车轮或其它导体分路，恰好使轨道电路继电器线圈电流减少到落下值时的列车分路电阻值（或导体的电阻值）就是该轨道电路的分路灵敏度。（3）极限分路灵敏度在轨道电路上各点的分路灵敏度不同，对于某一具体轨道电路来说，它的分路灵敏度应该以最小的分路灵敏度为准，称为极限分路灵敏度。（4）标准分路灵敏度我国现行规定标准分路灵敏度为0.06Ω，是和国际上规定的分路灵敏度是一致的。任何轨道电路在分路状最不利的条件下，用0.06Ω电阻进行分路时，轨道继电器应释放衔铁（连续式轨道电路）或不吸起（脉冲式）。否则不能保证分路状态的可靠工作。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

轨道电路认知轨道电路的基本工作状态1.调整状态调整状态指轨道电路完整和空闲、接收设备（例如轨道继电器）正常工作的状态。在调整状态，对于轨道继电器来说，它从钢轨上接收到的电流越大，它的工作就越可靠。但这个电流值将随着道床电阻、钢轨阻抗、发送电压的变化而变化。调整状态的最不利条件是：发送电压最低、道床电阻最小、钢轨阻抗最大，同时轨道电路长度为极限长度。在调整状态最不利因素下，轨道继电器应能可靠地工作，反映轨道电路的空闲状态。2.分路状态分路状态指当轨道电路区段有列车占用时，接收设备被轮对分路而停止工作的状态。分路状态的最不利条件是：发送电压最高、道床电阻最大、钢轨阻抗最小、列车分路电阻最大。在分路状态的最不利因素下，轨道电路接收设备应能可靠地停止工作，反映轨道电路区段有车占用。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