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INVESTIGATIONONINSULATIONELECTRICALAGINGMECHANISMOFINVERTERFEDACTRACTIONMOTORSINVERTERFEDTRACTIONMOTORSUSEDINMOTORTRAINUNITAREREGARDEDASTHERESEARCHOBJECTFORINSULATIONELECTRICAGINGMECHANISM,BASEDONRESEARCHPRODUCTIONSOFINSULATIONTECHNIQUEOFINVERTERFEDMOTORSHIGHFREQUENCYEQUIVALENTCIRCUITMODELSOFCABLEANDSTATORWINDINGAREESTABLISHEDTOSIMULATEOVERVOLTAGEOFMOTORTERMINALSANDUNEVENVOLTAGEDISTRIBUTIONOFWINDINGSANOVELHIGHFREQUENCYHIGHVOLTAGETESTSYSTEMHASBEENDEVELOPEDTOCARRYOUTLIFETIMETESTSOFTRACTIONMOTORWINDINGSCHANGETENDENCYOFDIELECTRICLOSS,PARTIALDISCHARGEANDTHERMALLYSTIMULATEDCURRENTTSCAREUSEDTODEDUCEINSULATIONELECTRICBREAKAGEMECHANISMHIGHFREQUENCYEQUIVALENTCIRCUITMODELSOFCABLEANDSTATORWINDINGAREESTABLISHEDTOSIMULATEOVERVOLTAGEOFMOTORTERMINALSANDUNEVENVOLTAGEDISTRIBUTIONOFWINDINGSTHESIMULATIONRESULTSSHOWTHATTHEOVERVOLTAGEISTHEFUNCTIONOFRISETIME,CABLELENGTHANDREFLECTIONRATIOONMOTORTERMINALSCRITICALLENGTHANDCRITICALRISETIMEISCORRESPONDINGONETOONETHEOVERVOLTAGEISUPTOTHEMAXIMUMVALUEASLONGASTHECABLELENGTHISREATERTHANTHECRITICALLENGTHANOVELHIGHFREQUENCYHIGHVOLTAGETESTSYSTEMHASBEENDEVELOPEDINPLACEOFINVERTERSTOCARRYOUTINSULATIONAGINGTESTPULSESQUAREWAVESAREGENERATEDBYIGBTANDAREENLARGEDBYHIGHFREQUENCYANDHIGHVOLTAGETRANSFORMERSINTHEDEVICETHEMAXIMUMVALUEOFHIGHFREQUENCYANDHIGHVOLTAGESQUAREWAVESISUPTO10KVTHERESULTSOFLIFETESTSOFMOTORWINDINGSINDICATETHATHERELATIONSHIPOFINSULATIONLIFETIMEANDTHEAMPLITUDEOFPULSESISTHEINVERSEPOWERLAWMODEL,THERELATIONSHIPOFINSULATIONLIFETIMEANDTHEFREQUENCYOFPULSESISEXPONENTIALMODELUNDERCONTINUOUSPULSESCONDITIONWHENTHETESTAMBIENTTEMPERATUREISBELOW200℃，THETEMPERATUREHASLITTLEINFLUENCEONINSULATIONLIFETIMEOFMAGNETWIREWITHCORONARESISTANTFILMINSULATIONANOVELPARTIALDISCHARGEDETECTIONDEVICEWASDEVELOPEDBYIMPULSECURRENTSENSOR,HANDCOMPUTERACCORDINGTOTHECHARACTERISTICSOFTHETESTEDSIGNALS,ANEWALGORITHMBASEDONWAVELETENVELOPEDETECTIONTECHNIQUEISPROPOSEDTOFILTEREMIFROMTHETESTSYSTEMANDSPACEELECTROMAGNETICWAVESBECAUSEOFTHEINFLUENCEOFVERYLARGEDV/DTANDHIGHFREQUENCYPLUSMINUSVOLTAGEDISCHARGESUNDERCONTINUOUSSQUAREWAVESCONDITIONAREDIFFERENTFROMTHOSEUNDERSINEVOLTAGECONDITIONONTHEONEHAND,LARGERDV/DTLEADSTOHIGHERBREAKDOWNVOLTAGEONTHEOTHERHAND,HIGHFREQUENCYPLUSMINUSVOLTAGECONVERSIONCAUSESALOTOFSPACECHARGECUMULATEDONTHEINSULATIONSURFACELARGEBREAKDOWNSPACECHARGERESULTINDISCHARGEPULSESWITHSHORTRISETIMEANDLARGEMAGNITUDETHENUMBER,MAGNITUDEANDPOWEROFPARTIALDISCHARGESINCREASEWITHTHETEMPERATURE,FREQUENCYANDVOLTAGECHANGEOFSQUAREWAVESTHENUMBEROFPARTIALDISCHARGEBECOMELARGEWITHTHEFREQUENCYOFSQUAREWAVEINCREASEINTHEUNITTIME,BUTITBECOMESSMALLINONEPERIODOFSQUAREWAVECONTRASTTESTSARECARRIEDOUTUNDERACAND10KHZSQUAREWAVEPULSECONDITIONSTHEDIFFERENCESBETWEENACAGINGANDSQUAREWAVEPULSEAGINGARESTUDIEDBASEDONCHANGECURVESOFDIELECTRICLOSS,PARTIALDISCHARGEPATTERNANDTSCTHESECURVESPROVETHATSQUAREWAVEPULSESBRINGMOREDEFECTSTHANACVOLTAGETOTHEINSULATIONMATERIALSUNDERQUAREWAVEPULSECONDITION,THETWOKEYFACTORSWHICHTOINSULATIONAGINGAREDISCHARGEADSPACECHARGEDAMAGEACTIONSOFPARTIALDISCHARGESANDSPACECHARGESAREINTENSIFIEDWITHVOLTAGE,FREQUENCYANDTEMPERATUREINCREASINGDUETOTHEDESTRUCTIONOFDISCHARGESUNDERTHESQUAREWAVECONDITION,THEWEAKNESSESOFINSULATIONSTRUCTUREWILLBREAKDOWNRAPIDLYIFPARTIALDISCHARGESOCCURDISCHARGECHANNELCOMESINTOBEINGASARESULTOFTHECOOPERATIONOFPARTIALDISCHARGESANDSPACECHARGESINSULATIONSURFACESAREDESTROYEDBYPARTIALDISCHARGESINJECTIONANDDRAWOFFOFELECTRICCHARGESGENERATINGBYCHARGESRESULTINMOLECULARCHAINFRACTUREINSIDEINSULATIONSTRUCTURESUBSEQUENTLY,DISCHARGECHANNELSAREEXPANDEDALONGTHEBREAKINGPOINTINTHEINSULATIONFINALLY,THEPROCESSLEADSTOINSULATIONISTHEUSEOFPOWERSEMICONDUCTORDEVICESWILLBETHEROLEOFONOFFFREQUENCYTOANOTHERFREQUENCYPOWERCONVERSIONPOWERCONTROLDEVICESWEARENOWMAINLYUSEDINCROSSFREQUENCYCONVERTERDIRECTWAYTOPAYVVVFINVERTERORVARIABLEFREQUENCYVECTORCONTROL,BEFORETHEADOPTIONOFPOWERFREQUENCYACPOWERINTODCPOWERRECTIFIERANDTHENCONVERTEDTODCPOWERSUPPLYFREQUENCYANDVOLTAGECANBECONTROLLEDACPOWERTOSUPPLYTHEMOTORINVERTERCIRCUITINGENERALBYTHERECTIFIER,INTERMEDIATEDCLINK,INVERTERANDCONTROLOFFOURPARTSPARTOFTHREEPHASEBRIDGERECTIFIERISNOTCONTROLLEDRECTIFIER,INVERTERPARTOFTHREEPHASEBRIDGEINVERTERIGBTANDPWMOUTPUTWAVEFORM,THEMIDDLEOFDCLINKFORTHEFILTERING,STORAGEANDBUFFERDCREACTIVEPOWERINVERTERSELECTION,SELECTIONCONVERTERTODETERMINETHEFOLLOWINGTHEPURPOSEOFTHEUSEOFVARIABLEFREQUENCY；CONSTANTVOLTAGECONTROLORCONSTANTCURRENTCONTROLINVERTERTYPEOFLOAD；SUCHASTHEVANEPUMPORPUMPS,SUCHASVOLUME,WITHPARTICULARATTENTIONTOTHEPERFORMANCEOFTHELOADCURVE,THEPERFORMANCECURVEDETERMINESTHEWAYSANDMEANSOFAPPLICATIONINVERTERANDLOADMATCHINGPROBLEM；VOLTAGEMATCHING；INVERTERRATEDVOLTAGEANDLOADINLINEWITHTHERATEDVOLTAGECURRENTMATCHING；ORDINARYCENTRIFUGALPUMP,RATEDCURRENTOFTHEINVERTERANDTHEMOTORRATEDCURRENTLINEFORASPECIALDEEPWATERPUMPS,ETCIFTHELOADISNECESSARYTOREFERTOTHEELECTRICALPERFORMANCEPARAMETERSTODETERMINETHEMAXIMUMCURRENTINVERTERCURRENTANDTORQUEMATCHING；THISSITUATIONINTHECONSTANTTORQUELOADORDECELERATIONDEVICETHATMAYOCCURFROMTIMETOTIMEINTHEUSEOFHIGHSPEEDMOTORDRIVEINVERTER,DUETOANTIHIGHSPEEDELECTRICMOTORSMALL,HIGHORDERHARMONICGENERATIONTOINCREASEVALUERESULTINGININCREASEDOUTPUTCURRENTTHEREFORETHEINVERTERFORHIGHSPEEDMOTORSELECTION,ANDITSCAPACITYTOBESLIGHTLYLARGERTHANTHESELECTIONOFGENERALMOTORSIFYOUWANTALONGCABLECONVERTERRUNNINGATTHISTIMETOTAKEMEASURESTOCURBALONGCABLEONTHEIMPACTOFCOUPLINGCAPACITANCETOAVOIDSHORTAGEOFINVERTEROUTPUT,SOINSUCHCIRCUMSTANCES,THEFREQUENCYCONVERTERTOENLARGETHECAPACITYOFAFILEORINTHEINVERTEROUTPUTINSTALLEDREACTOROUTPUTFORSOMESPECIALAPPLICATIONS,SUCHASHIGHTEMPERATURE,HIGHALTITUDE,ATTHISTIMEWILLCAUSELOWERCAPACITYINVERTER,INVERTERCAPACITYTOENLARGEABLOCKINTERNALHIGHPOWERINVERTERISTHEELECTRONICCOMPONENTS,EXTREMELYVULNERABLETOTHEEFFECTSOFTEMPERATURE,PRODUCTSAREGENERALLYCALLEDFOR055℃,BUTTHEWORKINORDERTOENSURESAFE,RELIABLE,SHOULDBETAKENINTOACCOUNTTHEUSEOFROOM,ITISBESTCONTROLLEDAT40℃UNDERINTHECONTROLBOX,THECONVERTERSHOULDNORMALLYBEINSTALLEDINTHEUPPERBOX,ANDSTRICTLYCOMPLYWITHTHEPRODUCTSPECIFICATIONOFTHEINSTALLATIONREQUIREMENTS,ABSOLUTELYDOESNOTALLOWEASYHEATHEATINGELEMENTSORCOMPONENTSCLOSETOTHEBOTTOMOFTHEINSTALLATIONOFINVERTERIITHEAMBIENTTEMPERATUREHIGHTEMPERATUREANDLARGETEMPERATURECHANGES,THEINVERTERINTERNALCONDENSATIONPRONETOTHEPHENOMENONOFPERFORMANCEOFTHEINSULATIONWILLGREATLYREDUCEANDMAYEVENLEADTOSHORTCIRCUITACCIDENTWHENNECESSARY,THENEEDTOINCREASETHEDESICCANTINTHEBOXANDHEATERINWATERTREATMENT,THEGENERALLYHEAVIERTHANWATER,IFTHETEMPERATUREVARIATION,THENTHEPROBLEMWOULDBEMOREPROMINENTIIICORROSIVEGASESTHEUSEOFTHEENVIRONMENTIFTHECONCENTRATIONOFCORROSIVEGAS,ANDNOTONLYTHECORROSIONOFLEADCOMPONENTS,SUCHASPRINTEDCIRCUITBOARDS,BUTALSOACCELERATETHEAGINGOFPLASTICDEVICESTOREDUCETHEINSULATIONPERFORMANCEIVVIBRATIONANDSHOCKEQUIPPEDWITHINVERTERCONTROLCABINETBYTHEMECHANICALVIBRATIONANDSHOCKWILLCAUSEBADELECTRICALTHERMOELECTRICATTHISTIME,APARTFROMIMPROVINGTHEMECHANICALSTRENGTHOFTHECONTROLCABINET,AWAYFROMTHEVIBRATIONSOURCEANDTHEIMPACTOFTHESOURCEBUTALSOTHEUSEOFANTISEISMICRUBBERPADFIXEDOUTSIDEANDINSIDETHECONTROLCABINETOFTHETYPEOFELECTROMAGNETICSWITCHCOMPONENTSGENERATEDVIBRATIONEQUIPMENTFORSOMETIME,SHOULDCARRYOUTINSPECTIONANDMAINTENANCEVELECTROMAGNETICINTERFERENCEINVERTERINTHEWORKOFRECTIFICATIONANDFREQUENCYASARESULT,HASCREATEDALOTOFTHESURROUNDINGELECTROMAGNETICINTERFERENCE,THESEHIGHFREQUENCYELECTROMAGNETICWAVESINTHEVICINITYOFTHEINSTRUMENT,APPARATUS,ACERTAINDEGREEOFINTERFERENCEACCORDINGLY,INSTRUMENTATIONANDELECTRONICSYSTEMSINSIDESHOULDBEOPTIONALMETALCASE,SHIELDINGOFTHEINSTRUMENTTRANSDUCERINTERFERENCEALLTHECOMPONENTSSHOULDBEGROUNDEDANDRELIABLE,INADDITION,ALLELECTRICALCOMPONENTS,APPARATUSANDINSTRUMENTSSHOULDBEUSEDTOCONNECTBETWEENTHECONTROLCABLESHIELDINGANDSHIELDSHOULDBEGROUNDEDELECTROMAGNETICINTERFERENCE,IFNOTHANDLEDPROPERLY,OFTENTHEENTIRESYSTEMWILLNOTWORK,RESULTINGINFAILUREOFORDAMAGETOTHECONTROLUNIT
