外文翻譯--變頻調(diào)速交流牽引電機(jī)絕緣電老化機(jī)理的研究.DOC_第1頁
外文翻譯--變頻調(diào)速交流牽引電機(jī)絕緣電老化機(jī)理的研究.DOC_第2頁
外文翻譯--變頻調(diào)速交流牽引電機(jī)絕緣電老化機(jī)理的研究.DOC_第3頁
外文翻譯--變頻調(diào)速交流牽引電機(jī)絕緣電老化機(jī)理的研究.DOC_第4頁
外文翻譯--變頻調(diào)速交流牽引電機(jī)絕緣電老化機(jī)理的研究.DOC_第5頁
已閱讀5頁,還剩1頁未讀, 繼續(xù)免費(fèi)閱讀

付費(fèi)下載

下載本文檔

版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡(jiǎn)介

InvestigationonInsulationElectricalAgingMechanismofInverter-FedACTractionMotorsInverter-fedtractionmotorsusedinmotortrainunitareregardedastheresearchobjectforinsulationelectricagingmechanism,basedonre-searchproductionsofinsulationtechniqueofinverter-fedmotors.Highfrequencyequivalentcircuitmodelsofcableandstatorwindingareestablishedtosimulateover-voltageofmotorterminalsandunevenvoltagedistributionofwindings.Anovelhighfrequencyhighvoltagetestsystemhasbeendevelopedtocarryoutlifetimetestsoftractionmotorwindings.Changetendencyofdielectricloss,partialdischargeandthermallystimulatedcurrent(TSC)areusedtodeduceinsulationelectricbreakagemechanism.Highfrequencyequivalentcircuitmodelsofcableandstatorwindingareestablishedtosimulateovervoltageofmotorterminalsandunevenvoltagedistributionofwindings.Thesimulationresultsshowthattheover-voltageisthefunctionofrisetime,cablelengthandreflectionratioonmotorterminals.Criticallengthandcriticalrisetimeiscorrespondingonetoone.Theover-voltageisuptothemaximumvalueaslongasthecablelengthisreaterthanthecriticallengthAnovelhighfrequencyhighvoltagetestsystemhasbeendevelopedinplaceofinverterstocarryoutinsulationagingtest.PulsesquarewavesaregeneratedbyIGBTandareenlargedbyhighfrequencyandhighvoltagetransformersinthedevice.Themaximumvalueofhighfrequencyandhighvoltagesquarewavesisupto10kV.Theresultsoflifetestsofmotorwindingsindicatethatherelationshipofinsulationlifetimeandtheamplitudeofpulsesistheinversepowerlawmodel,therelationshipofinsulationlifetimeandthefrequencyofpulsesisexponentialmodelundercontinuouspulsescondition.Whenthetestambienttemperatureisbelow200,thetemperaturehaslittleinfluenceoninsulationlifetimeofmagnetwirewithcoronaresistantfilminsulation.Anovelpartialdischargedetectiondevicewasdevelopedbyimpulsecurrentsensor,handcomputer.Accordingtothecharacteristicsofthetestedsignals,anewalgorithmbasedonwavelet-envelopedetectiontechniqueisproposedtofilterEMIfromthetestsystemandspaceelectromagneticwaves.BecauseoftheinfluenceofverylargedV/dtandhighfrequencyplus-minusvoltagedischargesundercontinuoussquarewavesconditionaredifferentfromthoseundersinevoltagecondition.Ontheonehand,largerdV/dtleadstohigherbreakdownvoltage.Ontheotherhand,highfrequencyplus-minusvoltageconversioncausesalotofspacechargecumulatedontheinsulationsurface.Largebreakdownspacechargeresultindischargepulseswithshortrisetimeandlargemagnitude.Thenumber,magnitudeandpowerofpartialdischargesincreasewiththetemperature,frequencyandvoltagechangeofsquarewaves.Thenumberofpartialdischargebecomelargewiththefrequencyofsquarewaveincreaseintheunittime,butitbecomessmallinoneperiodofsquarewave.ContrasttestsarecarriedoutunderACand10kHzsquarewavepulseconditions.ThedifferencesbetweenACagingandsquarewavepulseagingarestudiedbasedonchangecurvesofdielectricloss,partialdischargepatternandTSC.ThesecurvesprovethatsquarewavepulsesbringmoredefectsthanACvoltagetotheinsulationmaterials.Underquarewavepulsecondition,thetwokeyfactorswhichtoinsulationagingaredischargeadspacecharge.Damageactionsofpartialdischargesandspacechargesareintensifiedwithvoltage,frequencyandtemperatureincreasing.Duetothedestructionofdischargesunderthesquarewavecondition,theweaknessesofinsulationstructurewillbreakdownrapidlyifpartialdischargesoccur.Dischargechannelcomesintobeingasaresultofthecooperationofpartialdischargesandspacecharges.Insulationsurfacesaredestroyedbypartialdischarges.Injectionanddraw-offofelectricchargesgeneratingbychargesresultinmolecularchainfractureinsideinsulationstructure.Subsequently,dischargechannelsareexpandedalongthebreakingpointintheinsulation.Finally,theprocessleadstoinsulationistheuseofpowersemiconductordeviceswillbetheroleofon-offfrequencytoanotherfrequencypowerconversionpowercontroldevices.Wearenowmainlyusedincross-frequencyconverter-direct-waytopay(VVVFinverterorvariablefrequencyvectorcontrol),beforetheadoptionofpower-frequencyACpowerintoDCpowerrectifierandthenconvertedtoDCpowersupplyfrequencyandvoltagecanbecontrolledACpowertosupplythemotor.Invertercircuitingeneralbytherectifier,intermediateDClink,inverterandcontroloffourparts.Partofthree-phasebridgerectifierisnotcontrolledrectifier,inverterpartofthree-phasebridgeinverterIGBTandPWMoutputwaveform,themiddleofDClinkforthefiltering,storageandbufferDCreactivepower.InverterSelection,Selectionconvertertodeterminethefollowing:Thepurposeoftheuseofvariablefrequency;constantvoltagecontrolorconstantcurrentcontrol.Invertertypeofload;suchasthevanepumporpumps,suchasvolume,withparticularattentiontotheperformanceoftheloadcurve,theperformancecurvedeterminesthewaysandmeansofapplication.Inverterandloadmatchingproblem;voltagematching;Inverterratedvoltageandloadinlinewiththeratedvoltage.Currentmatching;ordinarycentrifugalpump,ratedcurrentoftheinverterandthemotorratedcurrentline.Foraspecialdeep-waterpumps,etc.Iftheloadisnecessarytorefertotheelectricalperformanceparameterstodeterminethemaximumcurrentinvertercurrentand.Torquematching;thissituationintheconstanttorqueloadordecelerationdevicethatmayoccurfromtimetotime.Intheuseofhigh-speedmotordriveinverter,duetoanti-high-speedelectricmotorsmall,high-orderharmonicgenerationtoincreasevalueresultinginincreasedoutputcurrent.Thereforetheinverterforhigh-speedmotorselection,anditscapacitytobeslightlylargerthantheselectionofgeneralmotors.Ifyouwantalongcableconverterrunningatthistimetotakemeasurestocurbalongcableontheimpactofcouplingcapacitancetoavoidshortageofinverteroutput,soinsuchcircumstances,thefrequencyconvertertoenlargethecapacityofafileorintheinverteroutputinstalledreactoroutput.Forsomespecialapplications,suchashightemperature,highaltitude,atthistimewillcauselowercapacityinverter,invertercapacitytoenlargeablock.Internalhigh-powerinverteristheelectroniccomponents,extremelyvulnerabletotheeffectsoftemperature,productsaregenerallycalledfor055,buttheworkinordertoensuresafe,reliable,shouldbetakenintoaccounttheuseofroom,itisbestcontrolledat40under.Inthecontrolbox,theconvertershouldnormallybeinstalledintheupperbox,andstrictlycomplywiththeproductspecificationoftheinstallationrequirements,absolutelydoesnotalloweasyheatheatingelementsorcomponentsclosetothebottomoftheinstallationofinverter.II.Theambienttemperature.Hightemperatureandlargetemperaturechanges,theinverterinternalcondensationpronetothephenomenonofperformanceoftheinsulationwillgreatlyreduceandmayevenleadtoshort-circuitaccident.Whennecessary,theneedtoincreasethedesiccantintheboxandheater.Inwatertreatment,thegenerallyheavierthanwater,ifthetemperaturevariation,thentheproblemwouldbemoreprominent.III.Corrosivegases.Theuseoftheenvironmentiftheconcentrationofcorrosivegas,andnotonlythecorrosionofleadcomponents,suchasprintedcircuitboards,butalsoacceleratetheagingofplasticdevicestoreducetheinsulationperformance.IV.Vibrationandshock.Equippedwithinvertercontrolcabinetbythemechanicalvibrationandshockwillcausebadelectrical.Thermoelectric.Atthistime,apartfromimprovingthemechanicalstrengthofthecontrolcabinet,awayfromthevibrationsourceandtheimpactofthesourcebutalsotheuseofanti-seismicrubberpadfixedoutsideandinsidethecontrolcabinetofthetypeofelectromag

溫馨提示

  • 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 人人文庫網(wǎng)僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。

評(píng)論

0/150

提交評(píng)論