地铁供电系统设计

地铁供电系统设计地铁供电系统设计TheDesignofSubwayPowerSupplySystem目录TOC\o"1-3"\h\u966第1章绪论 ③出口短路时，可取1.3；9.3.3直流短路计算的方法这里采用电路图法，按照实际供电网络，画出等效电路图，进行网络变换，在供电网络中只包括电阻。再按网络变换后的电路图利用欧姆定律、基尔霍夫定律进行计算。用电路图法进行短路电流计算，需要以下两个假设条件：(1)牵引网供电网络中，电源电压相同；(2)牵引变电所为电压源，其内阻因不同的短路点而有不同的数值。用电路图法进行短路电流计算，需要已知以下三个条件：牵引变电所直流母线电压U，V；牵引变电所内阻，；牵引网(接触网，走行轨)电阻，。用电路图法进行短路电流计算，按下列方法和步骤进行：(1)按实际供电网络画等效电路图；(2)进行网络变换；(3)分清网孔数目及其自阻和互阻；(4)按等效电路图的网孔数列回路方程式；(5)解联立方程组，求出未知数；(6)应用欧姆定律、基尔霍夫电流定律(KCL)、基尔霍夫电压定律(KVL)三条基本定律，进行数学推导，求出相应的计算公式。地铁牵引供电系统有单边供电和双边供电两种方式，当牵引网为双边供电时，某一点短路，不只是短路点处的牵引变电所向短路点供电，而是全线的牵引变电所都向短路点供电。全线的牵引变电所，是通过牵引变电所直流母线和牵引网进行电联结的[13]。下面分析相邻两侧牵引变电所影响的正常双边供电(考虑对侧接触网的影响)(1)其等效电路图可表示为9-3所示、网络变换如图9-4所示。图9-3考虑相邻两侧牵引变电所影响等效电路图图9-4网络变换等效电路图(2)根据KVL定律，按图9-3网孔①②③④列四个独立回路方程：回路1(9-11)回路2(9-12)回路3(9-13)回路4(9-14)对以上方程求解得到：(9-15)(9-16)(9-17)(9-18)(3)根据星—角变换，可得各馈电线短路电路如下：(9-19)(9-20)(9-21)(4)总短路电流(9-22)(5)各变电所短路电流(9-23)(9-24)(9-25)(9-26)式中U——牵引变电所母线电压，V；——牵引变电所内阻，；——接触网电阻，；——走行轨(上下行并联)，；；；；。9.3.4中山广场牵引降压混合所直流短路计算示例已知：牵引变电所双机组并联运行，1500V低碳钢接触网正常双边供电，短路时考虑对侧接触网及相邻牵引变电所的影响，供电距离均为2.6km，在距变电所800m处发生短路，求短路电流和各牵引变电所供出的短路电流。解：通过已知条件可得各参数如下：接触网电阻0.02；走行轨电阻：0.01(上下行并联)；牵引变电所内阻：(双机组并联)。利用以上参数及给定条件计算等效电路图中的电阻值：计算等效电路图中的计算各馈线电流计算短路点的总电流计算各变电所的短路电流第10章结论地下铁道工程是一项复杂的、多专业的综合性工程。随着我国现代化步伐的加快，各大城市建设地铁的热情日益高涨。本设计主要针对目前我国地铁的发展水平，以线地铁3号线一期工程为背景，对地铁供电系统的设计进行分析研究。本设计中从地铁供电系统设计的主要问题入手，详细分析了地铁3号线供电系统的组成和功能，结合实际工程案例给出了完整的设计方案。总的来说，本设计在地铁供电系统的工程设计中完成了如下工作：(1)地铁外部电源方案形式。分别列出了三种可行的供电方式，集中式供电、分散式供电和混合式供电，经分析比较选择了集中式供电方案，并给出具体理由。(2)地铁主变电所设计。涉及的内容主要有主变电所选址、电气主接线、主变压器选择、主变压器中性点接地等，并给出了相应的具体设计方案和主接线CAD图。(3)中压网络设计。对中压网络有两大属性即电压等级和构成形式进行了论述，给出了设计方案即牵引降压混合网络，采用同一电压等级。(4)牵引供电系统设计。主要分为牵引变电所设置和主接线两个部分，对牵引变电所的设置、牵引变电所的中压主接线和直流主接线的形式及其运行方式进行分析，给出直流牵引系统保护方案，并作出牵引供电系统主接线的CAD图。(5)供配电系统设计。主要分为中压接线和低压侧接线设计两个部分，对降压变电所的设置、牵引变电所的中压主接线和低压主接线的形式及其运行方式进行分析，并作出降压变电所供电系统主接线的CAD图。(6)地铁供电系统容量计算。主要包括牵引变压器供电计算，降压变压器容量计算，以及主变压器容量计算。并分别给出了计算结果。(7)杂散电流防护与接地。主要分为杂散电流与接地方案两个部分。对于杂散电流给出了相应的防护措施，同时也确定了合理的接地方案，即利用地下结构钢筋构成的等电位法拉第笼作为地铁电气设备的自然接地体。(8)短路计算。主要包括交流中压侧短路计算、牵引网直流短路计算。并结合实例分别进行了具体计算。以上设计成果对地铁供电系统的设计与施工，并提高其可靠性、安全性、经济性，具有一定的参考意义。参考文献[1]高满茹．建筑配电与设计[M]．第二版．中国电力出版社，2010．[2]刘介才．工厂供电[M]．第四版．机械工业出版社，2007．[3]黄德胜．地下铁道供电M]．第一版.中国电力出版社，2010．[4]于松伟．城市轨道交通供电系统设计原理与应用[M]．第一版．西南交通大学出版社，2008．[5]贺威俊．轨道交通牵引供变电技术[M]．第一版.西南交通大学出版社，2011．[6]王晓丽．建筑供配电与照明[M]．第一版．人民交通出版社，2008．[7]孙萍．建筑智能安全系统[M]．第一版．机械工业出版社，2010．[8]陈小川．铁路供电继电保护与自动化[M]．第一版.中国铁道出版社，2010．[9]刘宝林．建筑电气设计图集[M]．中国建筑工业出版社，2002．[10]刘宝林．现代建筑电气设计[M]．机械工业出版社，2003．[11]孙成群．建筑电气设计实例图册[M]．中国建筑工业出版社，2003．[12]LiuXiao-dong.ResearchonTC-SCdynamicsystemsimulationsteadyimpendancecharacteristics.AutomationofElectricpowersystem,1999,23(5)14-17[13]F.W.H.Yik,J.Burnett,I.Prescott,Predictingair-conditioningenergyconsumptionofagroupofbuildingsusingdifferentheatrejectionmethods[J]．EnergyandBuildings33(2001)151–166．附录附录A外文资料PowerSystemModelingforUrbanMassiveTransportationSystems1.IntroductionUrbanMassiveTransportationSystems(UMTS),likemetro,tramway,lighttrain;requiresthesupplyofelectricpowerwithhighstandardsofreliability.So,animportantstepinthedevelopmentofthesetransportationsystemsistheelectricpowersupplysystemplanninganddesign.Normally,thetrainsofaUMTSrequiresaDCpowersupplybymeansofrectifierAC/DCsubstations,knowastractionsubstations(TS);thatareconnectedtotheelectricHV/MVdistributionsystemofacity.TheDCsystemfeedscatenariesoftramwaysorthethirdrailofmetros,forexample.TheDCvoltageisselectedaccordingtothesystemtakingintoaccountpowerdemandandlengthoftherailway’slines.Typically,a600Vdc–750Vdcisusedintramways;while1500Vdcisusedinametrosystem.Someinterurban-urbansystemsusea3000Vdcsupplytothetrains.Fig.1presentsanelectricschemeofatypicaltractionsubstation(TS)withitsmaincomponents:ACbreakersatMV,MV/LVtransformers,AC/DCrectifiers,DCbreakers,tractionDCbreakers.As,itisshown,aredundantsupplysystemisplacedateachtractionsubstationinordertoimprovereliability.Inaddition,someelectricschemesallowthepowersupplyofthecatenariesconnectedtoaspecifictractionsubstation(A)sincetheneighbourtractionsubstation(B)byclosingthetractionsectioningbetweenAandBandopeningthetractionDCbreakers.Inthisway,thereliabilitysupplyisimprovedandallowsflexibilityformaintenanceofTS.So,animportantaspectfortheplanninganddesignofthiselectricpowersupplyisagoodestimationofpowerdemandrequiredbythetractionsystemthatwilldeterminetherequirednumber,sizeandcapacityofAC/DCrectifiersubstations.Ontheotherhand,thedesignofthesystemrequiresstudyingimpactsofthetractionsystemontheperformanceofthedistributionsystemandviceversa.Powerqualitydisturbancesarepresentintheoperationofthesesystemsthatcouldaffecttheperformanceofthetractionsystem.Thischapterpresentsusefultoolsformodeling,analysisandsystemdesignofElectricMassiveRailwayTransportationSystems(EMRTS)andpowersupplyfromDistributionCompaniesorElectricPowerUtilities.Firstly,asectiondepictingthemodelingandsimulationofthepowerdemandisdeveloped.Then,asectionaboutthecomputationoftheplacementandsizingofTSforurbanrailwaysystemsispresentedwherethemodelingisbasedonthepowerdemandmodeloftheprevioussection.Afterthat,twosectionsaboutthepowerquality(PQ)impactofEMRTSondistributionsystemsandgroundingdesignarepresented.Bothsubjectsmakeuseoftheloaddemandmodelpresentedpreviously.Fig.1.ATypicalTractionSubstation(TS)2.PowerdemandcomputationofelectrictransportationsystemsThissectionpresentsamathematicalmodelusefultosimulateurbanrailwaysystemsandtocomputetheinstantaneouspoweroftheElectricMassiveRailwayTransportationSystems(EMRTS)suchasametro,lighttrainortramway,bymeansofcomputingmodelsthattakeintoaccountparameterssuchasthegridsize,acceleration,velocityvariation,EMRTSbraking,numberofwagons,numberofpassengersperwagon,numberofrectifiersubstations,andpassengerstations,amongotherfactors,whichpermittosimulatethephysicalandelectriccharacteristicsofthesesystemsinamoreaccuratewayofarealsystem.Thismodelconnectsthephysicalanddynamicvariablesofthetractionbehaviourwithelectricalcharacteristicstodeterminethepowerconsumption.Theparametricconstructionofthetractionandbrakingeffortcurvesisbasedonthetractiontheoryalreadyimplementedinlocomotivesandurbanrails.Generally,therearethreefactorsthatlimitthetractioneffortversusvelocity:themaximumtractioneffort(Fmax)conditionedbythenumberofpassengersthatareinthewagons,themaximumvelocityofthetrain(orrail),andthemaximumpowerconsumption.Basedonthesefactors,asimulationmodelisformulatedforcomputingtheacceleration,speedandplacementofeachtrainintherailwaylineforeachtimestep(1second,forexample).So,thepowerconsumptionorre-generationiscomputedalsoforeachtimestepandknowingtheplacementofeachtrainintheline,thepowerdemandforeachelectricTSiscalculated.2.1PowerconsumptionmodelofanurbantrainThepowerconsumedbyonerailwayvehicledependsonthevelocityandaccelerationthatithasateachinstantoftime.Itscomputationisbasedonthetractioneffortcharacteristic(suppliedbythemanufacturerofthemotors),thenumberofpassengersandthedistancesbetweenthepassengers’stations(Vukan,2007),(Chenetal.,1999),(Perrin&Vernard,1991).Thedutycycleofanurbantrainbetweentwopassengers’stationsiscomposedbyfouroperationstates:acceleration,balancingspeed,constantspeedanddeceleration.Fig.2showsthebehaviorofthespeed,tractioneffortandpowerconsumptionofatractionvehicleduringeachoperationstateelapsedeithertimeorspace(Hsiang&Chen,2001).Fig.2.Velocity,TractionEffort,andPowerConsumptionofanUrbanTrainTravelbetweenadjacentPassengerStations(Hsiang&Chen,2001)Duringthefirststate(I),thevehiclemoveswithconstantpositiveacceleration,sothespeedincreases.Whenthevehiclereachesadeterminedspeedlowerthantheconstantspeed,thesecondoperationstatestarts.Inthisstate,theaccelerationdecreases,butthespeedkeepsincreasing.Inthethirdstate(III),thecruisespeedisreachedandtheaccelerationiszero.Inthefourthstate(IV),thebrakingoperationstartswithnegativeaccelerationuntilthemomentitdecelerateswithaconstantrateandfinallyitstopsatthedestinationstation(Vukan,2007),(Chenetal.,1999),(Perrin&Vernard,1991),(Hsiang&Chen,2001).2.2SimulationmodelThemodelpresentedatsection2.1allowsthecomputationofthepowerconsumptionandtraveltimecharacteristics(t,x)foreachtrainiintherailwayline.Naturally,arailwaylinesimulationmustincludeanumbernofpassengers’stationsandktrainstravelintheline(goandreturn).Theintegrationofthesecharacteristicsrequiresmodelingthemobilityofpassengersassociatedateachtrain.Itcanbesimulatedinaprobabilisticway,computingthenumberofpassengerscomingupandleavingthetrain(i)ineachpassenger’sstation(j)andthestoppingtimeofthetrainineachstation.Thisfirstpart,statedhereasModule1,usesthefollowingparameters:thepassengers’upanddownrates,andupanddowntimesperpassenger.3.Placementandsizingtraction(rectifier)substationsinurbanrailwaysystemsInthissection,amethodologyofplacementandsizingoftractionsubstationsunderanelectricconnectionscheme,inwhichhighreliablelevelsareguaranteed,ispresented.Inthisscheme,eachtractionsubstation(TS)isabletosupporttheloadofeachadjacentsubstation.ThatmeansthatinthecasewhenafaultoccursinoneTS,thereisasupportsystembasedonautomaticswitchesnormallyopenedthatcloseandallowthetwoneighboursubstationstosupplythepowertotheassociatedloadwiththefaultedsubstation(eachonewouldfeedhalfoftheloadofthefaultedone).Theinputdatatocalculatethesizingofsubstationisobtainedfromthepowerdemandcomputation,explainedintheprevioussection.Ontheotherhand,theplacementofeachTSisobtainedbyaheuristicoptimizationproblem.Thisproblemminimizesthetotalcostofagivenconfiguration,thatiscomposedofinvestmentcosts(rectifiers,transformers,andprotectionandcontrolcells),thecostofenergylossescomposedbyAClosses(associatedwiththetransformer)andDClosses(associatedtorectifiers)andthefailurecost,thatrepresentsthecostoftheannualexpectedenergynotsupplied(EENS).3.1Tractionsubstation(TS)configurationsAschemeofsupplyofanurbanrailwaysystemmustsatisfyelectricconditions,suchas:operatinglimits,voltagedropsthroughthecatenariesorthirdrail(calledhere,ingeneral,DCsection),andmaximumcapacityoftransformers.Theseconditionsmustbesatisfiedforsupplyingthepowerdemandindependentlyoftheoperatingstateofthesystem,i.e.,normalstateorapost-contingencystateafterafaultofaHV/MVsubstation,orTS,oroneDCsection.So,theTSlocationandconfiguration’sselectionarestronglylinkedproblems.Fig.3showsthreepossibleschemesofconnectionoftheMVnetworktoasetofTS.EachTSisdesignedtosupply(innormaloperationstate)aDCsectoroflengthL.Thewayofbehaveinafaultconditiondeterminesthefollowingthreepossibleconfigurations:1.Onetransformer-rectifierunitwithpossibilityofpowersupplyfromtheadjacentTS.EachTSactsasasupportofitsadjacentTS.Thisimpliesthatthesubstationsmustbeabletosupplyatleast1.5timesthelengthofthenormalDCsectionlength(3L/2).2.Twotransformer-rectifierunitsineachtractionsubstation.ThisconfigurationmeanstheredundancyinthemainequipmentoftheTS.Incaseofafaultinonetransformerand/orrectifier,theparallelunitmustsupplythetotalpowerdemandoftheTS.3.Twotransformer-rectifierunitsineachTSandsupportofadjacentDCsection.Thisisthecombinationofconfigurations1and2.ThismeansthatthereisredundancyineachtractionsubstationandthereisalsopossibilityofsupportofadjacentDCsectionfeeder.Fig.3.ConfigurationsofTractionSubstations’Connection3.2OptimizationproblemAminimizationofthetotalprojectcostissolvedfordeterminingthequantityoftractionsubstations,theirconnectionconfigurations,andtheirlocations.Theoptimizationisaconstrainedproblemthatguaranteestheelectricalrequirements,likevoltagelevelsandhighreliabilityrequirements.ThedistancebetweenTSisassumedtobeequal,andeachTSislocatedatthemiddlepointoftheDCsectionthatitsupplies,asFig.3shows.3.3TechnicalconstraintsThevoltagedropbetweenasupplypointandautilizationpointmustnotbemorethan15%innormaloperationandasmaximum30%inspecialcases(Arriagada&Rudnick,1994).ThesespecialscasesmaybetheoutageofasubstationorthelastDCsectionintheroute.3.4ApplicationtothestudycaseTheunitarycostoffaultwasassumed1074US$/kWh,fromreliabilityanalysis.Simulationsweredoneforthreelevelsofload:high(themaximumnumberofvehiclesinservice),medium(halfofthetotalvehiclesinservice),andlow(withnovehiclesinservice).ThesimulatorallowsthecalculationofpowerlossesinN-0state,andthedemandofeachsubstationforN-0andN-1contingenciesstate.Simplecontingencies(N-1)atthemaximumloadweremadeinordertosizingtheTSwhenconfigurations1and3areused,togivesupportofadjacentTS.While,normalstateoperationwasusedforsizingTSinconfiguration2.4.PowerqualityimpactofurbanrailwaysystemsondistributionsystemsPowerqualityphenomenaoriginatedinpowerdistributionsystemsimpactsontheelectricalpowersupplysystemofUMTSand,atthesametime,powerelectronicsusedinthetractionsystemimpactsonthepowerquality(PQ)serviceofthedistributionsystem.Inaddition,thepowerdemandofUMTSpresentshighandfastvariationsasconsequenceoftheoperationcyclesofeachtrain-vehicleandthenon-coincidenceofoperationalcyclesamongseveralvehicles.So,PQphenomenaaretimevariable(Singhetal.,2006).TheidentificationofPQproblemsinpowersystemsrepresentsanimportantissuetothedistributionutilities.TheharmonicdistortionisoneofthemainPQphenomenaintheelectricalsystemfeedinganEMRTSbecausetheinjectionofharmonicsbyitsnonlinearloadsflowsthroughthenetworkandaffectsotherconsumersconnectedtothedistributionsystem.Inaddition,thecomputationofthetotalharmonicdistortion(THD)intheACsideoftherectifiersubstationattherailwaysystemmusttakeintoaccountthetimeloadvariabilityateachTS.So,theinstantaneouspowerloadmustbecomputedasfunctionoftimeanddistanceasitwasexplainedatsection2.OncethecurrentconsumptionineachTSisobtained,itispossibletoidentifythevariationoftheTHDduringthetime.4.1ProbabilisticmodelGenerally,deterministicmodelshavebeenadoptedfornetworkharmonicanalysis;however,thesemodelscanfailformodellingtheloadvariationinsystemssuchastherailways’electricalsystem(Changetal.,2009).So,aprobabilisticanalysistocharacterizetheharmoniccurrentloadsproperlymustbeusedinordertoobtainanaccuratemodel.AnEMRTSischaracterizedbyfluctuatingloadsduetothedifferentoperationstatesofthetrainsinthetractionsystem.Thus,theharmonicsinjectionfromtherectifiersubstationstotheMVnetworkcausesthatthecurrentharmonicspectrumatthedistributionsystem’sconnectionpoint(PCC)variesovertime.So,eachtractionsubstationcanberepresentedasaharmoniccurrentsourcethatprovidesaprobabilisticspectralcontentatthePCC(Riosetal.,2009).Then,itisnecessarytoperformthevectorsumofseveralharmonicsources(i.e.tractionsubstations)atthedistributionsystem’sconnectionpointtodeterminethetotalharmonicdistortion.Therearetwomethodstoevaluatetheeffectofdifferentnon-linearloads:theanalyticalmethodandMonteCarlosimulationmethod.Thecompleximplementationofanalyticalmethodsforlargepowersystemsstudiesinvolveslittlepracticalapplicationinrealsystems.Bycontrast,MonteCarlosimulationhasprovedtobeapracticaltechnique(Casteren&Groeman,2009)basedonthelowcorrelationbetweendifferentharmonicloads(independenceofthesources).4.2ActivepowerfilterallocationmethodologyTheharmonicdistortionproducedbyrailways’systemsatthedistributionsystem’sconnectionpointcanbereducedusingpassiveoractivepowerfilters(APF).However,duetotherandomandtimevariabilityoftheharmonicdistortionintractionsystems,itisrequiredanactivepowercompensationwiththeabilityofadaptationtodifferentloadconditions.Passivefiltersaredesignedwithfixedparametersandforspecificharmonics,sothistypeoffilterdoesnothavetherequiredability.Bycontrast,APFsbasedonthep-qtheorybecameaneffectivesolutionintractionsystems;normally,theyareusedfordynamicharmonicsuppression(Xu&Chen,2009).Thistypeofcompensationpresentstheadvantageofeliminatingawiderangeofharmonicssimultaneously.Ontheotherhand,thetractionsystemhasseveralrectifiersubstationsandfromtheeconomicpointofviewitisdifficulttoinstallanAPFineachTSduetoitshighcost.Then,itisnecessarytoallocateAPFsinthemostsensitivepositionsintheownpowersystemoftheEMRTSusingtheleastnumberoffiltersandminimizingtheirsize.Animportantfactortobeconsideredinthedecisionofharmoniccompensationintractionsystemisthesuddenfluctuationoftractionloadbecausethisdynamicbehaviorisalsoobservedintheharmonicdistortion,asithasbeenexplainedintheprevioussection.5.GroundinginDCurbanrailwaysystemsAprimaryrequirementtoensuretheappropriateoperationofanyelectricalsystemistoguaranteepersonnelandsystemsafety,eitherundernormalandfaultconditions.So,groundingisthemostimportantcomponenttocontrolelectricalsystemfailures.GroundinginelectrictractionsystemsrequiresadifferenttreatmentthanintypicalACelectricalsystems,becauseoftheexistenceoftractionsubstationsAC/DCofhighcapacity,thehighvariableloadcharacteristicintimeanddistance,thedirectcontactoftherailswiththeearth,thecurrentflowthroughthegroundduringnormaloperatingconditionsthatcancausecorrosionofundergroundmetallicelements,theappearanceofstepandtouchvoltagethatcanjeopardizetheintegrityofpersons.Thegroundingsystemiscomposedbytwosubsystems.Thefirstone(subsystem1)assuresthepersonnelsafetyandtheprotectivedeviceoperation;while,thesecondone(subsystem2)isusedtogroundthenegativepoleintheDCsideoftherailway’stractionsubstation.Thegroundingsubsystem1isusedtogroundallmetallicstructures:boxes,protectivepanels,pipeline,bridges,passengerplatforms,etc.Therearetwowaystoconnectthissubsystem:-HighResistanceGroundingMethod(HRGM):Aconstantvoltageof25VdcisappliedbetweentheTS’shousingandtheground,inordertoenergizearelaytosendtheopeningordertotheprotectionequipment.Whenthevoltageleveldecreases,otherrelayissettosendtheopeningordertotheprotectionifabigcurrentflowsthroughthemodule.-LowResistanceGroundingMethod(LRGM):Aconstantvoltageof1VdcisappliedbetweentheTS’shousingandtheground.Inthiscasenoresistanceisused,butadirectconnectionismadetothegroundsystem.Inaddition,whentherelaysandprotectionsdetectthevoltage’sabsence,theywillsendtheopeningordertotheprotectionsystem.6.ConclusionThischapterhaspresentedusefultoolsforpowersystemsmodeling,analysisandsystemdesignofElectricMassiveRailwayTransportationSystems(EMRTS)andpowersupplyfromDistributionCompaniesorElectricPowerUtilities.Firstly,asectiondepictedtopresentthemodelingandsimulationofthepowerdemandwasdeveloped.Then,asectionaboutthecomputationoftheplacementandsizingoftractionsubstationsforurbanrailwaysystemswaspresentedwherethemodelingisbasedonthepowerdemandmodelofthepreviouslymentioned.Afterthat,twosectionsaboutthepowerqualityimpactofEMRTSondistributionsystemsandgroundingdesignarepresented.ThesetoolsallowtheoptimizationofthedesignschemeofrailwayelectrificationforUMTS,takingintoaccountanadequatesizingandnumberoftractionsubstations,andthenumberandlocationofharmonicfilterstoimprovethepowerqualityofthesystem.附录B中文翻译城市大规模交通系统的电力系统建模介绍城市大规模交通系统(UMTS)，如地铁，电车，轻轨，需要高标准和可靠性的电力供应。所以，这些交通系统的发展中的重要一步，是电力供应系统的规划和设计。通常情况下，列车的UMTS要求的直流电源，通过整流AC/DC变电站，比如牵引变电站(TS)，起到连接城市电力高压/中压配电系统的功能。直流系统将电能送入地铁电车接触网或第三轨。根据用户功需求和铁路线的长度，考虑供电系统的直流电压选择。通常情况下，在轻轨中使用的直流600V到750V电压，在地铁系统中使用直流1500V。一些城市也使用直流3000V给电动列车供电。图1给出一个典型的牵引变电所(TS)，其主要组成部分：交流断路器MV，MV/LV转换装置，AC/DC整流器，直流断路器，牵引直流断路器。为，供应的可靠性得到改善，并能使牵引供电系统更灵活地发挥作用。了提高可靠性，每个牵引变电站都装置了备用电源系统。此外，有些供电方案允许通过直流断路器和隔离开关将来自邻居牵引变电站(B)A和B(A)之间的牵引变电所联系起来。在这种方式下，增强了牵引变电所间供电的灵活性。因此，这种电力供应的规划和设计的一个重要方面是由牵引系统来确定牵引变电所的数量，规模和容量电力需求。另一方面，该系统的设计需要研究考虑牵引系统的影响，对配电系统的性能等。供电系统的操作可能影响牵引系统电源质量的不稳定。图1一个典型的牵引变电所(TS)本章介绍些适合于建模的有用工具，分析和研究大规模的电气铁路运输系统(EMRTS)的设计方案，这些电力供应来源于电源分销公司或电力公用事业。首先，简要介绍电力需求开发的建模和仿真。然后，根据上一节的电力需求进行部分城市铁路系统的位置和大小的TS计算建模。之后，电能质量(PQ)的影响在于配电系统接地设计EMRTS这个部分，这个科目需要使用以前的负载需求模型。2.电力运输系统的电力需求计算本节介绍一种有用的数学模型来模拟城市铁路系统的计算模型，考虑到用户的参数，通过计算电力系统大规模的铁路运输系统的瞬时功率(EMRTS)，如地铁，轻轨或电车，加速度，速度变化，制动EMRTS，车厢数量，每节车厢的乘客数，整流变电站的数量，客运车站等。除其他因素外，允许使用一个更为准确的方法在实际的系统中对其进行物理和电特性的仿真。此模型将牵引变电所的静态和动态变量的电气特性联系起来，以确定电力功率消耗。基于城市轨道牵引理论的基础，参数化的牵引和制动的作用曲线已应用于城市轻轨和地铁轨道。一般来说，有三个因素限制了机车牵引速度：最大牵引力受限于空调车辆乘客的数量，列车的最大速度，最大功耗。基于这些因素，制定一个仿真模型是在每个时间段(1秒，例如)计算每趟列车在铁路线的加速度，速度和位置。所以，功耗或再生制动也分为每一个时间段来计算，还需知道行进中每个列车的具体位置，来计算每个TS的电力需求。2.1城市列车的电力消耗模式电动列车的功耗取决于列车在每个时刻的速度和加速度。其计算的基础依赖于牵引力电气特性(电机由生产商提供的)，乘客的数目和各车站之间的距离(Vukan，2007年)，(Chen等，1999)，(睿Vernard，1991)。电动列车在两个车站之间呈现以下四种运行状态：加速，惰行，恒速和减速。图2示出了列车在每一个运行状态的速度，以及电动车辆的牵引力和功率消耗经过的时间和空间状态(Hsiang，2001)。图2两车站间列车速度，牵引力和功耗(Hsiang&chen，2001年)在第一状态(I)中，列车的移动正加速度恒定，所以速度将增加。当车辆到达低于恒定速度的预定速度时，第二运行状态开始。在这种状态下，加速度减小，但速度会持续增加。在第三状态(III)时，达到稳定速度，列车加速度为零。在第四状态(IV)中，列车开始制动操作进入负加速度状态，它以恒定的速率减速，最后停止在目标车站(Vukan,2007),(Chenetal.,1999),(Perrin&Vernard,1991),(Hsiang&Chen,2001).2.2仿真模型在2.1节提出的模型可以让我们对每列列车在铁路线的功耗和运行时间的特性(T，X)进行计算。当然，此仿真须涉及一条铁路线上n座乘客站和k辆(往返)电动列车。这些电气特性的集成需要依赖于每个列车乘客数量的流动性建模。它可以采取概率模拟的方式。在每个车站(j)进入或离开列车(i)和在各站的列车的停止时间来进行乘客的数量计算。首先，就像模型1一样，使用以下参数：乘客的上车和下车率以及每名乘客上下车历时的时间。3.城市轨道交通牵引变电所(整流器)的布局和大小在本节中，牵引变电所的位置和大小的选择方法，依据可靠地电气接线方案其供电可靠性水平得到了保障。在这个方案中，每个牵引变电所(TS)能够承担相邻变电站的负荷。这意味着，在一个牵引变电所(TS)的情况下，当故障发生时，供电系统的相应常开触点自动合闸，并允许两个相邻变电站分别提供供电故障的变电站(每一个变电所承担一半的故障)的负载的一半。根据需求功率来计算变电站的容量大小，在前一节中已经说明。另一方面，每个牵引变电所(TS)的位置都存在着相应的优化问题。此问题中一个给定的配置的总成本投资，即组成(整流器，变压器和保护与控制器)，组成的AC损耗(与变压器)和DC能量损失(相关联的成本最小化整流器)及整流失败成本，代表年度预期的能耗供给(EENS)的成本。3.1牵引变电所(TS)配置城市轨道系统供电方案必须满足相应的电力条件，如：操作限制，通过接触网或第三导轨(通常，在一般情况下，直流部分)的电压下降和大容量的变压器。独立系统需要电力系统必须能在以下各状态下正常的运行，即在正常状态或高压/中压变电站故障应急状态下，或者牵引变电所，或一个DC部分故障时等。因此，TS的位置和配置的选择是密切相关的问题。图3示出了三种可能方案的MV中压网络连接到一组TS。每个TS旨在提供(在正常运行状态下)的DC牵引部分的长度