Thegenerator第18頁共18頁InstructionforinstallationandtestThegenerator1.Relateddocumentationsandstandards1.1.TheChinesestandard(GB50170-92):Codeforconstructionandacceptanceoftherotatingelectricmachine1.2.TheChinesestandard(GB50150-91):Standardforhand-overtestofelectricequipment1.3.TheChinesestandard(DL408-91):Operationcodeforpowerplantsafety1.4.TheChinesestandard(DL560-95):Operationcodeforelectricsafetyinhighvoltagelaboratory1.5.TheChinesestandard(DL/T5043-95):Designstandardforelectricallaboratoryofthermalpowerplant1.6.TheChinesestandard(DL/T5161.7-2002):Specificationforconstructionqualitycheckoutandevaluationofelectricequipmentinstallation2.Receiptandstorage2.1.Examinethestateofthedevicesandthematerialsreceivedtocheckthatitcorrespondswithwhatwasordered.2.2.Checkallpackagesforexternalsignsofdamage.2.3.Pleasecheckconditionandqualityofthedevicesandthematerials,andcomparethemwithapackinglist.2.4.Ifonunpacking,whichmustbecarriedoutcarefully,anydamageorirregularityisnoted,notifythiswithindefiniteperiodofreceiptofthegoods,notificationmustindicatetheshippingnotenumber.2.5.Ifthedevicesistobestoredforevenshortperiodsbeforebeingputintoservice,afteronreceiptitisadvisabletoputitbackintoitsrelativecontainerandcoveritwithawaterprooftarpaulin.Useadryanddust-freeambientforstoragewithoutanyaggressivechemicalagents.Placethedeviceandanyfixedpartonahorizontalsurfacenotindirectcontactwiththefloor,butonasuitablesupport.2.6.Selectalocationforthedeviceinaclean,dry,vibration-freeareawithmoderatetemperature.2.7.Withregardtolifting,followtheseinstructions:thedevicesmustbeplacedonasturdysurface,andpreferablyliftedusinganappropriateliftingforktruck.Theuseofropesis,however,permitted:inthiscasetheliftingropesmustbehookedfirmly.3.Installationofthegenerators3.1.Outletsleevecheck3.1.1.WhentheElectricalMachinePlantdeliveredthegoods,theoutletsleeveandleadofthesleeveofthegeneratorhadalreadybeenfittedintheoutlethoodofthegenerator,andcheckedtobeuptostandardbyelectricaltest.Inliftingtheoutlethoodbythemaintenanceworkers,theconstructorsshouldcooperatewiththemintimetocheckandclearupthesleevemainlead,leadconnector,andtakecaretotheliftingsoastheconnectorofsleevemainleadnottocollideagainstanything.3.1.2.Checkthesleevecarefully.Itssurfacemustbeclean,nodamageandcrackle.Theflangeofoutletboxshouldbetightlyincombinationbothwiththesleeveflangeconnectingsurfaceandtheconnectingsurfaceofthegeneratorbody.3.1.3.Intheprocessoferectioncheck,greatcautionmustbetaken,soastheporcelainsleevenottobedamagedbycollision.3.1.4.Wheneverenteringtheoutlethoodtowork,thepersonshouldcontactthemaintenancespecialty,beforeopeningtheblockingboardofmanhole,itmustbeconfirmedthatthereisnoairpressureinsidethegenerator,soasnottobehurtbytheboardforcedopenbythepressuregas.3.2.Erectionofstatoroutletsoftconnectingwireandtransitionlead3.2.1.Useapieceofclothdippedingasolineorcarbide-chlorinationtoclearoffthedirtandoilstainsoneachconnectingsurface.Usearulertochecktheconnectingsurfacetoseewhetheritissmooth.Thesilver-platinglayershouldnothavegroundsurface,crumblingoruncoveredpart,itshouldnotbefiled.Alltheconductingcontactsurfacesshouldbematch,sothatthecontactsurfaceisnotlessthan70%.3.2.2.Firstrectifythesoftconnectingwire,sothatitisalignedwiththegeneratoroutlet,then,accordingtotheiroppositeposition,choosesuitablesoftwiretomatch,asfaraspossibletomakeitreceivetheleastforceaftertheconnectingboltbeingfastened.3.2.3.First,fitintheinsulationringaccordingtothedrawing,andpastetheconnectingsurfaceswithepoxybeforefitting.Fortransitionlead,fitX,Z,Y,A,C,B.3.2.4.Alltheconnectionsshouldbetightlyfastened.Thetorquevaluesareasfollows:M16-78.5～98.1Nm,M24-274.6～343.2Nm.3.2.5.Accordingtodrawingserectinsulationwaterlead,outlethoodwaterpipefittingandwaterlead.3.3.Hydraulicandflowtestincooperationwiththemaintenanceafterwaterlinehavingbeenerected.3.4.Outletbushingairtighttest3.4.1.Mountingairtighttesttoolsaccordingtodrawings.3.4.2.Letcleancompressedairenterintotheoutletbushingwithpressure0.35±0.02MPafor8hours.Thereshouldbenoleakage.3.4.3.Jointlychecktheoutletbushing,softconnectingwire,andtransitionleadtoconfirmthattheyarealluptostandard.3.5.Mattersneedingattentionfortheoutletinsulationbinding3.5.1.Outletinsulationbindingisproceedingintheoutlethood.Sincetheplaceisnarrowanddifficultforconstruction,preparationfortheconstructionmustbewelldonewithgreatcare,thebindingprocedurebewellknown,thevariousinsulationmaterialsandtoolsforbindingbeprepared,thegradeofallmaterialstobeusedforbindingmustbecheckedtomeettherequirement.Itisnotpermittedtousewettedmaterialorthatexceedingthetimelimit.3.5.2.Theoutletinsulationbindingisameticulousworkwithhightechnologyrequirement,anditmustbedonebyexperiencedexpert.Inthewholeprocessofbinding,theenvironmenttheremustbekeptcleananddry,withgoodventilationandlight.Forthatpurpose,thespecialventilatorandwalkinglampcanbeprovidedwith.3.5.3.Oncethebindingisstarted,itmustproceedsuccessivelyandbefinishedatonego.Andthebindingtimeshouldbeasfaraspossiblyshortenedtoavoidtheinsulationbeingwetted.Inconstruction,gauzemaskandrubberglovesshouldbewornsoasnottopollutetheinsulatingmaterial.3.5.4.Intheprocessofbinding,theremustnotbeanyaircavityinit.Theedgesandcornersandhollowplaceshouldbetrowelwithfillings.Andinwrapping,theinsulationtapeshouldbetightlypulled.3.5.5.Sincecombustiblesareusedinthebindingprocess,smokingorlightingfiresisstrictlyforbidden.Andnecessaryfire-fightingequipmentsuchasfoamextinguisher,andetc.shouldbeprepared.3.6.Connectionandwrappingbetweenthestatorwindingsandtheterminals3.6.1.Cleanthesurfaceofmetalbyalcoholoracetone.3.6.2.Installitem17flexibleconnection.Torqueis600kgcm.3.6.3.Wrapwithitem50:0.5nomexpapertoroot,fixitbyitem45glassadhesivetapeSCOTCH27#.3.6.4.Halflappedwrap10layersofitem46:0.5×30silasticadhesivetapeQY6351-05atleast.3.6.5.Halflappedwrap2layersofitem47:0.10×25non-alkaliglassfibertapeET100,paintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone,betweenlayersandonsurface.3.7.Insulationofallbareconductorsurfaces.3.7.1.Afterwatercircuitconnectionfinished,hydrostatictestandwaterflowtestshouldbecarriedoutatsite.3.7.2.Afterwaterpressuretestandwaterflowtest,insulatethebareconductorsurfaceasfollows:.Halflappedwrap1layerofitem39:0.10×25non-alkaliglassfibertape,thenpaintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone..Plasteritem42filler,whichisepoxyresin618+solidifyingagent650+micapowder,smoothlyonanyrecessandarrises..Halflappedwrap22layersofitem37:0.14×25T5440-1insulationtape,paintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone,betweenlayers..Halflappedwrap1layerofitem38:0.10×25dacronfibertape,paintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone..Halflappedwrap2layersofitem39:0.10×25non-alkaliglassfibertape,paintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone.3.7.3.ThetorquetotightenthenutsofTeflonhose&item8:waterpipeis32kgm.3.7.4.Soakitem40:2dacroncarpetanditem43:0.3×25fiveweftglassfibertapeinitem49:glue,whichisepoxyresin6101+solidifyingagent650,beforebinding.3.7.5.Paintitem48:redinsulationlacquer162ontheinsulationwrappedsurfaceatlast.3.7.6.Beforeinstallingwindingconnectionsitem22,item27,item31anditem32,installitem12insulationringonitem30terminalbushing,andpaintitem49glue,whichisepoxyresin6101+solidifyingagent650,onjointsurface.3.7.7.Afterwindingconnectioninsulated,halflappedwrap1layerofitem39:0.10×25non-alkaliglassfibertapeatbareconductorinsideofinsulationtubes,putinsulationtubesuponitem12insulationringaccordingtodrawingNo.3Q7398-S,halflappedwrap1layerofitem43:0.3×25fiveweftglassfibertapearoundinsulationtubestofixsawnblocksandpaintitem44glue,whichisepoxyresin618+solidifyingagent593+diluent501+acetone,fillinsulationtubeswithitem42filler,whichisepoxyresin618+solidifyingagent650+micapowder.3.7.8.Afterstatorterminalassembledatsite,thewaterflowtestofeachbranchshouldbecarriedout.Thewaterpressureshouldbeinrangeof0.03~0.1MPa,theflowVmustsatisfywithnextexpression:(Vmax.–Vmin.)/Vmin.<20%.0kVpartialleakagecurrenttestand21kV,1min.partialhighvoltagetestshouldbecarriedouttotheinsulationswrappedatsite.3.8.Thecompositionandweightproportionofsomematerials3.8.1.Epoxy:epoxyresins6101+solidifier650,weightproportion:1:13.8.2.Mid-temperaturesolidifyingepoxy:epoxyresins618+solidifier593+diluent501+acetone,weightproportion:100:35:35:153.8.3.Filler:epoxyresin618+solidifier650+micapowder,weightproportion:1:1:23.9.Afteralltheinsulationbindingworkisfinished,giveanoverallcheckandcleaningtothegeneratorstatoroutlethood,cleanoutalltheremainingmaterialoddsandends.Makesurethatthereisnothingleftthere.3.10.Cooperatewiththedebugginggivealocalelectricityleakagetestandlocalworkfrequencypressurebearingtesttothepartsthathaveundergonetheinsulationtreatmentattheworksite.3.11.Examinationofthegeneratorbodiesisasshownintable3.11.Table3.11.:ExaminationofthegeneratorbodiesExaminationitemsPropertyQualitystandardsMethodsandtoolsforexaminationExaminationofthestatorironcoresAppearanceoftheironcoresClean,withoutcorrosionanddamageTouchandinspectionBetweenlaminationsoftheironcoresWithoutloosenessandmetalshortcircuitInspectionGroovewedgesExaminationofthewedgesMainWithoutbreakandloosenessPullExamineendsofthegroovewedgesSolidVoidlengthofeachgroovewedgeMain≤1/3ofgroovewedgelengthMeasurebyainstrumentCorrugatedplatesInaccordancewiththemanufacturespecificationCheckbyaspecialtoolorinstrumentExaminationoftheventilatedpathsMainWithoutblocksInspectionandventilationExaminationofthestatorwindingsAppearanceofinsulationlayersMainClean,withoutdamage,bubbleandcrackInspectionFastenerandbindCompleteBindoftheendwindingsTightPullAnti-loosemeasuresCompleteandreliableExaminationoftheinsulationwaterpipesIntervalsbetweentheinsulationwaterpipesandtheendcoversWithouttouchInspectionIntervalsbetweentheinsulationwaterpipesAppearanceoftheinsulationwaterpipesWithouthollowExaminationofthepipesMainUnobstructedCheckbyventilationInsulationresistancesbetweeninnerandouterpipesMain≥1MΩCheckbya1000Vmeg-ohm-meterExaminationoftherotorsIroncoresExaminationoftheventsMainUnobstructedCheckbyventilationPaintlayersonsurfaceWithoutpeelingandcorrosionInspectionConnectionbetweenthewindingleadsandtheringcollectorsMainSolidandcontactPullandcheckthetestreportsExaminationofthebalancersMainWithoutdeformationInspectionRingcollectorsExaminationofoutersurfaceSmooth,withoutcorrosionanddamageInspectionExaminationoftheventsMainUnobstructed3.12.Qualitystandardsinstallingthegeneratoraccessoriesareasshownintable3.12.Table3.12.:InstallationofthegeneratoraccessoriesExaminationitemsPropertyQualitystandardsMethodsandtoolsforexaminationInstallationofthebrushracksandthebrushholdersExaminationoftheinsulationgasketbushingsandtheinsulationpadsWithoutdamageanddirtInspectionInsulationresistancetogroundMain≥1MΩMeasurebya2500Vmeg-ohm-meterGapsbetweenthebrushholdersandtheringcollectorsMain2mm~4mmCheckbyaruleTighteningboltsandanti-loosemeasuresCompleteandtightPullInstallationoftheelectricbrushesElectricbrushtypesandmanufacturesMainSametype,samemanufactureInspectandcheckmanufacturecertificatesConnectionoftheelectricbrushleadsSolidPullIntervalsbetweentheleadsandtheturningpartsWithouttouchInspectionGapsbetweentheelectricbrushesandthebrushholdersMain0.1mm~0.2mm,movableupanddownPullandcheckbyaclearancegageExaminationofinsulationpadsoftheelectricbrushesMainPerfectInspectionContactareasbetweentheelectricbrushesandtheringcollectorsMain≥75%ofcrosssectionofaelectricbrushInspectgrindedtrackonsurfaceSpringpressureInaccordancewiththemanufacturespecificationCheckdependonthemanufacturespecificationInstallationofthebushingsElectrictestofthebushingsMainQualifiedCheckthetestreportsVisualexaminationofthebushingsWithoutpeelingandcrackInspectionSealtestofthewatercoolingpathsMainInaccordancewiththemanufacturespecificationCheckdependonthemanufacturespecificationConnectionofflangesbetweenthebushingsandtheterminalboxesMainTightboltsandgoodsealInspectandcheckbyatorquewrenchConnectionbetweenthebushingsandtheoutletsofthegeneratorsExaminationofthecontactsurfaceCleanandperfectsilverplatedsurfaceInspectionConnectionoftheboltsMainTight,withoutclosemagneticcircuitsInspectandcheckbyatorquewrenchAnti-loosenutsCompleteandtightInspectionConnectionoftheinsulationwaterpipesSolid,goodsealWrappingtreatmentforinsulationMainInaccordancewiththemanufacturespecificationCheckdependonthemanufacturespecificationEarthConnectionoftheearthedwiresMainSolid,goodcontactPullandconductancecheckEarthofthefoundationsObviousearthattwopointsandaboveInspection3.13.Pressuredeviationoftheconstantpressurespringsonsamepoleoftheelectricbrushcannotexceed5%.Adjustpressureofnon-constantspringsto14~25kPainordertonoflashontheelectricbrushes.3.14.Qualityofhydrogenmustconformtofollowingrequirement:3.14.1.Purityofhydrogenmustbehigherthan95%.3.14.2.Oxygencontentinthegasmixturemustn’tbehigher2%.3.14.3.Absolutehumidityofhydrogenmustn’tbehigher10g/m3.3.15.Qualityofcoolingwatermustconformtofollowingrequirement:3.15.1.Conductivitymustbelowerthan2μS/cm.3.15.2.Hardnessmustbelowerthan2μmol/L.3.15.3.pHvalueequal6.5~6.Thegeneratorsshouldbedriedifinsulationresistanceislowerthan1MΩ/kV×20kV=20MΩ.Speedrisingtemperaturecanbe5~8℃/hour.Turntherotors180oevery2hoursiftemperatureofthedryinggeneratorswiththerotorsisexceedthan70℃.Watertemperaturecanbelowerthan70℃whendrythegeneratorstatorswithhotwatercirculation.Temperatureonjointsbetweenthestatorwindingsandtheinsulationwaterpipesshouldbelower70℃.3.17.Checkrecordsofthegeneratorsareasshownintable3.17.Table3.17.:CheckrecordsofthegeneratorsProjectnameGeneratortypeRatedcapacity(MW)Ratedvoltage(kV)Ratedcurrent(A)Excitingvoltage(V)Excitingcurrent(A)Speed(r/min.)Frequency(Hz)PowerfactorWiringmannerCoolmannerExcitingmannerManufactureManufacturingnumberManufacturingdateExaminationitemsResultsRemarkCleanstatorironcores,windingsandframes;tightboltsWithoutcorrosion,damageandmetalshortcircuitonthestatorironcoresWithoutcrack,teatandloosenessonthestatorgroovewedges;withoutimpurityintheventilationpathsandtheventsWithoutdamageoninsulationsurfaceofthestatorwindings;solidfastersandbindsontheendsWithouthollowanddamageonthecoolwaterpipes,withoutblockinthepipesWithoutcontactbetweencoolwaterpipesandendcovers;goodinsulationofthestatorjunctionpipesWithoutpeelandcorrosiononanti-corrosivepaintlayeroftherotorironcoresWithoutblockintheventsSolidfastersandbalancersontherotorsSmoothsurfaceoftheslidingrings,withoutcorrosionAirpressuretestforcoolwaterpipesofthestatorwindings,ventilationtestoftherotorsElectrictests,I&CtestsExaminationconclusionAcceptanceopinionSignatureDateConstructiongroupConstructionteamQualitydepartmentSupervisorydepartmentOwner3.18.Checkrecordsforoutletsconnectionandinsulationwrappingofthegeneratorsareasshownintable3.18.Table3.18.:CheckrecordsforoutletsconnectionandinsulationwrappingofthegeneratorsProjectnameGeneratortypeRatedcapacity(MW)Ratedvoltage(kV)Ratedcurrent(A)Excitingvoltage(V)Excitingcurrent(A)Speed(r/min.)Frequency(Hz)PowerfactorWiringmannerCoolmannerExcitingmannerManufactureManufacturingnumberManufacturingdateExaminationitemsResultsRemarkPerfectandcleancontactsurfacebetweenleadsandoutletsofthegeneratorsSpecificationandnumberofconnectionboltsbetweenleadsandoutletsFasteningtorqueofconnectionboltsbetweenleadsandoutlets(Nm)WithoutclosemagneticcircuitbecauseofboltconnectionOrderofinsulationwrappingmaterialsTechnologycontrolofinsulationwrappingQualityofinsulationwrappingWithstandvoltagetestafterwrappingtheoutletsExaminationconclusionAcceptanceopinionSignatureDateConstructiongroupConstructionteamQualitydepartmentSupervisorydepartment4.Testofthegenerators4.1.Cancarryoutstatorironcoretestifwithoutthemanufacturetestreports.4.1.1.Circuitdiagramofstatorironcoretestisasshownfollow:4.1.2.YokecrosssectionSofthestatorironcorescanbecalculatedasfollow:S=K(L1-nb)[(D1-D2)/2-hc].WhereKissparefactorofthestatorironcores,K=0.93~0.95forpaintinsulationbetweensiliconsteelsheets,K=0.9forpaperinsulation;L1istotallengthofthestatorironcoresincentimeter;nisnumberofventilationchannelsofthestatorironcores;biswidthofventilationchannelsofthestatorironcoresincentimeter;D1isouterdiameterofthestatorironcoresincentimeter;D2isinnerdiameterofthestatorironcoresincentimeter;hcistoothheightofthestatorironcoresincentimeter.4.1.3.Turnsoftheexcitingcoilcanbecalculatedasfollow:Wl=U2×108/(4.44fSB)WhereU2ispowersupplyvoltageontheexcitingcoilinvolt;fisfrequencyoftestpowersupply;Sisyokecrosssectionofthestatorironcoreincm2;Bismagneticfluxdensityatthesteelcoreyokes.Iff=50Hz,B=10000Gaussduringtest,thenWl=45U2/S.4.1.4.Currentoftheexcitingcoilinamperecanbecalculatedasfollow:I=πH0(D1-h)/WlWhereh=(D1-D2)/2-hcisyokeheightsofthestatorironcores;H0isampereturnnumberperunitlength,H0=2.15~2.3At/cmifB=10000Gauss.4.1.5.Poweroftheexcitingcoilinvolt-amperecanbecalculatedasfollow:Pl=IU24.1.6.Turnsofthemeasuringcoilcanbecalculatedasfollow:Wm=U1Wl/U2.WhereU1isvoltageonthemeasuringcoilinV.4.1.7.Energizetheexcitingcoilandmeasureinitialtemperaturesatyokesandteeththenevery10min.andmeasurepowerPFeinthemeasuringcoilinwatt.Durationoftestis90min.4.1.8.Actualvalueofthemagneticfluxdensityingaussduringtestcanbecalculatedasfollow:B’=(45U1/WmS)×1044.1.9.Ironlossperunitatyokesofthestatorironcorecanbecalculatedasfollow:ΔPFe=[PFe(10000/B’)2]/GWhereG=πS(D1-h)×7.8×10-3isweightoftheironyoke.4.1.10.Maximumdifferenceoftheteethtemperaturesin℃canbecalculatedasfollow:Δt1=(t1-t2)(10000/B’)2Wheret1ismaximumtemperatureoftheteethin℃,t2isminimumtemperatureoftheteethin℃.Δt1shouldnotexceed15℃.4.1.11.Maximumtemperatureriseoftheironcorein℃canbecalculatedasfollow:Δt2=(t3-t0)(10000/B’)2Wheret3ismaximumtemperatureoftheironcorein℃,t0isinitialtemperatureoftheironcorein℃.Δt2shouldnotexceed25℃.4.2.MeasureACimpedanceandpowerlossoftherotorwindingsoutofthestators.4.2.1.Thepeakvaluesoftheimposedvoltageshallnotexceedtheratedexcitationvoltage.4.2.2.Connectionforthetest4.2.3.Thetestprocedure:.ClosetheswitchS..RegulatetheautotransformerAtr.,andrisevoltagefrom0Vtothetestvoltageslowly..Recordthevaluesofvoltage,currentandpower.4.2.4.CalculationCalculatethevalueoftheimpedancez=V/IWhereVistestvoltage,Iistestcurrent..Calculatetheimpedanceangleφ=arccos(W/VI)whereφisimpedanceangle,Wisactivepower..CalculatetheimpedanceZ=z∠φ4.3.MeasureDCresistancesoftherotorwindings.DCresistancesoftherotorwindingsshallbemeasuredundercoldstate,duringwhich,thedifferencebetweenthetemperatureonthewindingsurfaceandthatofambientairshallnotbegreaterthan±3℃.Ascomparedwiththevalue0.162766Ωat15℃deliveredbythemanufacturerthedifferenceshallnotexceed2%.4.4.Measureinsulationresistanceoftherotorwindingsbya500Vmeg-ohm-meter.Insulationresistanceoftherotorwindingsshallbehigherthan1MΩ.4.5.WithstandACvoltageontherotorwindingsis10×455×80%=3.64kV.ACvoltagewithstandtestontherotorwindingscanbereplacedbymeasurementofinsulationresistanceusinga2500Vmeg-ohm-meteralso.Testdurationis1min.4.6.Measureinsulationresistancesonexcitationcircuitsofthegeneratorsortheexciterstogetherwithallequipmentconnectedbya500Vmeg-ohm-meter.Theinsulationresistanceshallnotbelowerthan0.5MΩ.Drawoutallelectronicequipmentduringmeasurement.4.7.CarryoutACvoltagewithstandtestonexcitationcircuitsofthegeneratorsorexciterstogetherwithallequipmentconnectedexcludingtherotors.Thetestvoltageis1000Vandtesttimeis1min.Drawoutallelectronicequipmentduringtest.4.8.Measureinsulationresistanceofthegeneratorbearingsbya1000Vmeg-ohm-meter.Theinsulationresistanceshallbehigherthan1MΩ.4.9.MeasureDCresistanceofthearc-quenchingresistorsandtheauto-synchronizingresistors.Differenceshallnotexceed10%ascomparedwiththedataplatevalue.4.10.MeasureDCresistanceofthestatorwindings.4.10.1.DCresistanceshallbemeasuredundercoldstate.Differencebetweenwindingsurfacetemperatureandambienttemperatureshallnotbegreater±3℃whenmeasuring.4.10.2.Thedifferenceofcoldresistancebetweenthemeasurementsofanytwophaseswillnotmorethan1.0%oftheminimumresistancevaluewhichmeasuredfromoneofthesethreephases,aftertakingaccountofthevariationinthelengthofleadandconnectrings,andtherelativechangeshallnotbegreaterthan2%alsoincomparedwiththecorrespondingvalue1.658mΩat15℃deliveredbythemanufacturer.4.11.Measureinsulationresistanceandabsorptionratioofthestatorwindingsbya2500Vmeg-ohm-meter.4.11.1.Timeoftest:Measuringstatorwindinginsulationresistanceshallbecarriedoutduringthewatercirculating,afterthestatorcoilwatersystemwascompleted.4.11.2.Connectionforthetest4.11.3.Sequenceoftest:.Thestatorwindingshallbegroundedanddischarged..Measureandrecordairtemperatureandhumidity..Connectthelinesinaccordwiththefigure.11.3.4.Recordtimesandthevaluesoftheinsulationresistanceatthattimewhenmeasuringbya2500Vmeg-ohm-meter..ThelineatHpointshallbedisconnectedafterfinalvaluewasrecorded..Thiscoilshallbedischargedthoroughbyagroundbar..Measureinsulationresistanceofotherphasewindingsasantecedentsequence.4.11.4.Safetyprecaution:Becausethestatorwindingisequivalenttoalargecapacitoragainsttheearth,itmustbedischargedthoroughaftermeasuringinsulationresistance,inordertoavoidgettinganelectricshockanduncorrectedmeasurement.4.11.5.Insulationresistanceofthestatorwindingsatt℃afterdryingshouldbehigherthan5MΩandRt=[UN×1.6(100-t)/10]/(1000+SN/100)=[20000×1.6(100-t)/10]/(1000+353000/100)=4.415×1.6(100-t)/10MΩ.4.11.6.Measurestatorwindinginsulationresistanceat15sand60sseparately.Theabsorptionratioistheratiooftheresistanceat60sto15s.4.11.7.Theunbalancefactorofinsulationresistancebetweenphasesshallnotbelargerthan2.Theabsorptionratioshallbelessthan1.8.Measureinsulationresistanceofthewaterbuspipestogroundbya1000Vmeg-ohm-meter.Measuredvaluemightbehigherthan1MΩifwithoutwaterinthepipes,30kΩifwithwaterinthepipes.4.12.DCvoltagewithstandtestandleakingcurrentmeasurementonthestatorwindings4.12.1.Conditionsofvoltagewithstandtestonthestatorwindings:.Thecoolingwatermustconformtothedemandandcirculatenormallyinthecooling-watersystem..Thetestsshallbemadeonephaseafteranotherbythetestingapparatuswhoseratedvoltageis2500Vforthestatorwindinginsulationresistanceoftheinnerwatercooledmachine.Thevaluesofthestatorwindinginsulationresistance,whicharephase-to-phaseandphase-to-ground,areabove1000MΩat1minuteaftersupplypower..Hotwatershallbecirculatedthroughthegeneratorstatorcoolingwaterpipewhenanyphasewindinginsulationresistanceisbelow1000MΩ.Temperatureofthewatershallbecontrolledwithin70~80℃..Thevoltagewithstandingtestonstatorwindingshallbemadeafterthejointsbetweenthestatorwindingandtheconnectionlinewerewrappedup..Testonhydrogencooledmachineshallbecarriedoutbeforefilledwithorafterwithdrawnhydrogen.Itisprohibitedtocarryouttestinthecourseofdisplacinghydrogen.4.12.2.ThecircuitforDCvoltagewithstandingtestonstatorwinding:Therotorslideloopsofthegeneratorshallbelinkedbybarewireandgroundedtogetherwiththeshaft,thethermometersandthesecondarycoilsofthecurrenttransformer,whichshallbeassembledonthecoverofterminals,shallbeshort-circuitedandgrounded.Thebus-ductshallbeshort-circuitedandgroundedalso.Thegeneratorbodyshallbegroundedalso.Thebus-ductandterminalsshallb