外文翻译电力机车交直分相装置上产生电弧的仿真实验.docx

外文翻译电力机车交直分相装置上产生电弧的仿真实验.docx

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外文翻译电力机车交直分相装置上产生电弧的仿真实验

外文翻译---电力机车交-直分相装置上产生电弧的仿真实验

附录A（原文）

ASimulationofArcGenerationatAC-DCNeutralSectionofElectricRailway

YoungsooHan,KyuhyoungChoi

Abstract--Thispaperprovidesanexperimentalandtheoreticalanalysisofthearcdischargesgeneratedbetweencontactwireandpantographofhighspeedrailway.Avideo-basedarcdetectiondeviceisinstalledontheKTXtrain,andarcdischargesaremeasuredfora45.87kmtracksectionofhighspeedrailwayinKorea.Itismeasuredthattherateofcontactlossis0.3%whichislowerthantheregulatedvalueof1.0%forhighspeedtrain,andarcdischargesinducedby21smallsizecontactlossesand6mediumsizecontactlossesoccurcontinuouslyalongthetrack.Thepowerofarcdischargebetweencontactwireandpantographiscalculatedas9.0~22.5[kW]whichisapproximatelyone-hundredthofthatofthearcdischargesgeneratedattheneutralsectionofcontactwire.Theresultsofthemeasurementandtheanalysissupposethatastudybefollowedtosuppressarcdischargesandcontactwiredamagesforthesafeoperationofhighspeedrailway.

IndexTerms—Electricrailway;arcdischarge;contactloss;contactwire;pantograph;neutralsection.

I.NOMENCLATURE

S/S:

Sub-StationofElectricRailway

SP:

SectioningPost

SSP:

Sub-SectioningPost

AT:

Auto-Transformer

TF:

TrolleyFeeder

AF:

Auto-TransformerFeeder

FPW:

FaultProtectiveWire

NW:

NeutralWire

NS:

NeutralSection

CCTV:

ClosedCircuitTelevision

EMI:

ElectromagneticInterference

LAN:

LocalAreaNetwork

MCB:

MainCircuitBreaker

KTX:

KoreaTrainExpress

II.INTRODUCTION

Catenarysystemsplayaimportantroleinsupplyingelectricpowerwithoutinterruptiontotrainsmovingfast.Thepantographsinstalledontraincollectcurrentsfortractionwhilekeepingincontactwiththecatenarysystem.Arcdischargesoccurbetweenthecontactwireandthepantographs,whenthepantographshappentolosecontactwiththecontactwire.ArcdischargealsooccurswhenthetrainpassesthroughtheAC-DCneutralsectionofthecatenarysystemwhereelectricityisnotsupplied.Thesearcdischargesgiverisetomanyproblemssuchasspoilingthecontactwireandthepantographs,andinducingEMIphenomena,audiblenoisesandotherenvironmentalpollutions.Arcdischargesgenerallyhavelargeheatingpowerwhichmayspoilthesliderofpantographmadeofsinteredalloyandevenbreaksthecontactwires.VoltagesurgesinducedbyarcdischargesmayproduceEMIproblemstothesmallsizeenvironmentormal-operationofelectronicdevicesonthetrain.Thedamagescausedbyarcdischargewillbemorecriticalforhighspeedrailway.Thefastertrainmoves,themoredifficulttokeepingincontactwithcatenaryforpantograph.Moreover,astrainspeedsup,thetraintractioncurrentsshouldbeincreased,whichinevitablygiverisetolargerarcdischarges.Thispaperprovidesanexperimentalandtheoreticalanalysisofthearcdischargesgeneratedbetweenthecontactwireandthepantographofhighspeedrailway.AdesignatedarcdetectiondeviceisinstalledontheKTXtrain,andarcdischargesaremeasuredfora45.87[km]tracksectionofhighspeedrailway.Arcgenerationfrequency,arccurrentandarcsizeismeasuredalongthetrack.Adataanalysisandanarcpowermodelissuggestedtoo.

III.ARCDISCHARGESBETWEENCONTACTWIREANDPANTOGRAPH

ThepowersupplysystemofelectricrailwayconsistsofS/Sandcatenarysystem.S/Sconvertsthreephase154[kV]electricpowertosinglephase25[kV]beingsuitableforsupplyingtotrain.HighspeedrailwayadoptsATfeedingsystemwhichcansupplylargeelectricpowerforlongdistanceasshowninFig.1.TheS/SsuppliesAC50[kV]toAT,andATsupplyAC25[kV]totrain.Theconvertedelectricpowerissuppliedtotrainbywayofthecatenarysystemwhichiscomposedofacontactwire,amessengerwireandhangers.Themainpurposeofthecatenarysystemistosupplyelectricpowerwithoutinterruptiontotrainsmovingfast.Thepantographsinstalledontraincollectelectricpowerwhilecontactingthecontactwireofthecatenarysystem.

Fig.2.Showstheconfigurationofthecatenarysystem.Thepantographisconnectedtothecontactwirebyitsliftforceagainstthecontactwire.Contactwiressupportedbyhangersandsupportingstructureshasunevenstiffnesspointswhichgiverisetocontactlosses.Moreover,astrainspeedup,contactlosshappensmorefrequently.Arcdischargesoccurbetweenthecontactwireandthepantographs,whenthepantographshappentolosecontactwiththecontactwire.

Thecontactlossphenomenaareclassifiedintothreegroupsaccordingtotheirduration;smallsize,mediumsizeandlargesize.Smallsizecontactlossisinducedbydelicatevibrationofpantograph,andcontinuesforseveraltenthsofasecond.Mediumsizecontactlossesoccurwhentrainspassthroughtheunevenstiffpointofthecontactwire,andcontinuesforasecondandbelow.Largesizecontactlosses,continuingforseveralseconds,areinducedbyjumpingmovementsofpantographafterpassingthroughbracketsupportingpointsofcontactwire.

Contactwireshaveseveralneutralsectionsinsulatedfromotherpartsofcontactwires,inotherwordsdeadsections,whichdividethesectionshavingdifferentphasesanddifferentsupplyvoltagessuchasAC25,000[V]orDC1,500[V].Trainsshouldgointotheneutralsectionsaftermakingnotch-offoperationwhichbreaksthetraincurrentbyMCB,otherwisethetraincurrentisinterruptedbytheneutralsectionwhichresultinalargearcdischargebetweenthecontactwireandthepantographasshowninFig.2.Thisarcdischargealsohappenswhentraingointothevoltage-suppliedsectionfromtheneutralsection.

IV.MEASUREMENTOFCONTACTLOSSBETWEENCONTACTWIREANDPANTOGRAPH

A.Measurementdevice

Fig.4.Showsthesystemblockdiagramofarcmeasurementdevice.Thedevice,installedontheKTXtrainmovingatthespeedof300[km/h],measurescontactforcebetweencontactwireandpantograph,vibrationaccelerationofpantograph,andtheshapeofarcdischarge.Straingaugesareinstalledonthebowandarmsofpantographtomeasuretheaccelerationandcontactforce.Table1showsthespecificationsofthesensors.TheimageofarcdischargeiscapturedbyCCTVcameraactivatedbyarcdetectionsensor.Fig.5showsacapturedimageofarcdischarge.Allthedatameasuredbyon-boarddevicearetransmittedtowaysideserverviawirelessLAN.

B.Measurementdataanalysis

Themeasurementhasbeencarriedoutatthe45.78[km]tracksectionofhighspeedrailwaywith300[km/h]trainoperation.Table2showstheresultsofthemeasurement;time,locationofarcdischarge,arcstrength,thelengthofcontactloss,trainspeed,arccurrent,andpantographvoltage.Fig.6showatrainspeedprofilewithvoltageandcurrentdistributions.WhileKTXtrainmovesonthe45.78[km]tracksection,21smallsizecontactlossesand6mediumsizecontactlossesareobservedandrecorded.Largesizecontactlosswasnotdetectedattheexperiment.Therateofcontactlossisdefinedas;

rateofcontactloss=sumofcontactlosstime×100[%]

（1）

totaloperationtime

Koreanrailroadcorporationsuggeststherateofcontactlossforhighspeedrailwayshouldbelowerthan1.0[%].BasedonthemeasureddatainTable2,therateofcontactlossiscalculatedas0.31[%],whichmeansthecatenarysystemandthepantographofKTXfulfilltheregulationinKorea.Nevertheless,itshouldbenotedthatsomearcdischargesareoccurringcontinuouslyduringthehighspeedoperationofKTX.

C.Modelingofarcdischarge

Theinstantaneouspowerofarcdischargeisdescribedbyarcvoltageva,andarccurrentiasfollows,

（2）

TheaveragepowerofarcdischargecanbecalculatedbyintegratingovertheperiodT.

（3）

ItisreportedthatthevoltageandcurrentofarcdischargeatACcircuithavethewaveformsshowninFig.7[8].ThearcvoltagehasconstantvalueVduringhalftheperiod,depictedbysquarewave.Thus,theequation（3）foraveragepowerofarcdischargecanbesimplifiedbysettingva=Va.

ThecurrentwaveformofACarcdischargeinFig.7isapproximatelysinusoidalhavingsomeharmonic.Neglectingtheharmonicswhichisevaluatedasseveralhundredthsoffundamentalwave,arccurrentcanbeapproximatedas

（5）

Consequently,theaveragepoweris

（6）

WhereIiseffectivevalueofACcurrent,andVisarcvoltagethatcanbemeasuredbyvoltmeter.

Thearcdischargebetweencontactwireandpantographhasthefollowingcharacteristics.Arccurrentsareverylargeupto500[A].Arcdischargebetweencontactwireandpantographcanbesimulatedbyarcdischargebetweenbarandplate.Fig.8showsatypicalvoltage-currentcharacteristicsofhighcurrentarcdischargebetweenbarandplate.Asthearccurrentis500[A]inTable2,arcvoltagecanbeestimatedas20~50[V]accordingtodisplacementbetweencontactwireandpantographfromFig.8.Thus,thepowerofarcdischargebetweencontactwireandpantographiscalculatedtobe9.0~22.5[kVA]byequation（6）.Thepowerofarcdischargebetweencontactwireandpantographisapproximatelyone-hundredthofthatofthearcdischargesgeneratedattheneutralsectionofcontactwire.

V.CONCLUSION

ArcdischargesbetweenthecontactwireandpantographhavebeenmeasuredontheKTXtrainalong45.87kmtrackusingavideo-basedarcdetectiondevice.Althoughtherateofcontactlossismeasuredas0.3%whichislowerthantheregulatedvalueof1.0%,arcdischargesoccurscontinuouslyalongthetrackinducedby21smallsizecontactlossesand6mediumsizecontactlosses.

Thepowerofarcdischargebetweencontactwireandpantographiscalculatedas9.0~22.5[kW]whichisapproximatelyone-hundredthofthatofthearcdischarges