简介:Atypeofnovelinverterpowersupplysystemforhigh-powertwin-wirepulsedgasmetalarcwelding(GMAW)ispresentedmainlyfordealingwiththedisadvantagesoftheconventionalpowersupplyfortwin-wirepulsedGMAWofwhichtheoutputpowerisgenerallydifficulttoincreaseduetolimitationsofthepowerofsemiconductorsandthepowerdensityofmagneticdevices.Inthepowersuppliesforthemasterandslavearcs,thedigitalsignalprocessor(DSP)TMS320F28335isusedtoformtheDSP-basedsynergiccontrolsystemforparallelhigh-powerpulsedGMAW,whichachieveshigh-poweroutputoftwoparallelinverterscontrolledbyasingleDSP;master-slavecommunicationisachievedbyusingecontrollerareanetwork(eCAN)moduleofDSP,thusrealizinganti-phasepulseoutputofhigh-powertwin-wirepulsedGMAWandreducingtheinterferencebetweentwinarcs.Theexperimentresultsdemonstratethatthedesignedinverterpowersupplysystemforhigh-powertwin-wirepulsedGMAWcanbringabouthigh-powerefficiencyofwelding,stableweldingprocessandproperformationofwelds.
简介:Developmentofweldingtechnologyofhydroelectricpowerequipment¥ZHENGBenying(DongfangElectricalMachineryWorks,SichuanDeyang(61800...
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简介:Alotofexperimentalmethodshavebeenbroughtforthtoassessthedynamiccharacterofthearcweldingpowersource,butuptonow,thisissuehasnotbeensolvedverywell.Inthispaper,basedonthefuzzylogicreasoningmethod,adynamiccharacterassessingmodelforthearcweldingpowersourcewasestablishedandusedtoanalyzethedynamiccharacteroftheweldingpowersource.Threedifferenttypesofweldingmachinehavebeentested,andthecharacteristicinformationoftheelectricalsignalssuchasre-strikingarcvoltage,lowweldingcurrentandsoonoftheweldingprocesswereextractedaccuratelybyusingaself-developedweldingdynamicarcwaveletanalyzer.Theexperimentalresultsindicatethatthismodelcanbeusedasanewassessingmethodforthedynamiccharacterofthearcweldingpowersource.
简介:Full-bridgeZero-Voltage-SwitchPWMconvertercombinesadvantagesofthePWMcontroltechniqueandresonanttechnique.However,FullZVSisachievedonlyunderlargeloadcurrentbecauseresonanttankofthiscircuitismadeupoftheparasiticcapacitanceofthepowersemiconductorsandtheleakageinductorofthetransformerprimary.Inthispapertwosaturableinductorsasmagneticswitchesareaddedtosecondary,sooutputinductorisalwaysreflectedtoprimaryandassistsresonanttransition.FullZVSisachievedunderlowerloadcurrent.Theabove-mentionedinvestigatedresultsarevalidatedbythecomputerizedsimulationandhardwarecircuitexperiment.
简介:TheenergymodelwasfoundedtocalculatethecriticalpowerofkeyholeformationbyusingthelimitprincipleinCW(continuouswave)Nd:YAGlaserdeeppenetrationweldingprocess.Themodelwasvalidatedbyexperiments.Theresultsshowthattherearetwoerrorsbetweenthecalculatedcriticalpowerofkeyholeformationandthatofexperiments:oneisthatthecalculatedresultsislessthanthoseofexperiments,whichiscausedbynotconsideringtheenergylossby!heatconductioninthemodelofkeyholeformation.Theotheristhatthereis0/9mmerrorbetweentheaxisofthecalculatedcurveofcriticalpowerwithlocationoflaserfocusandthatofexperimentalcurve,whichisinducedbytheexcursionoflaserfocusinlaserdeeppenetrationwelding.Atlast,thetwoerrorswererevisedaccordingtotheanalysesoftheerrors.
简介:Adigitalarcweldingpowersupplywasdesignedwiththeadvancedreducedinstructionsetcomputermachine(ARM)andembeddedreal-timemulti-taskoperatingsystemmicroC/OS-Ⅱ.TheARM,withitspowerfulcalculatingspeedandcompleteperipheralequipments,isverysuitabletoworkasthecontrollerofthedigitalpowersupply.ThemicroC/OS-ⅡtransplantedinARM,helpstoimprovetherespondentspeedagainstvariousweldingsignals,aswellasthereliabilityofthecontrollingsoftware.Theweldingprocessconsistsofninetasks.Thetasksofgreatsignificanceonreliabilityofthewelder,forexample,theA/Dconversionofcurrentandvoltage,enjoytoppriority.Toavoidsimultaneous-sharingonA/DconverterandLCDmodule,twosemaphoresareintroducedintoensurethesmoothperformanceoftheweldingpowersupply.Provenbyexperiments,theARMandthemicroC/OS-Ⅱcangreatlyimproveboththerespondentspeedandthereliabilityofthedigitalwelder.
简介:Thedigitalizationofarcweldingpowersourcemainlydependsonthedigitalizationofarcweldinginverter,sothatmaincircuitandcontrollingsystemcangivefullplaytoadvantages.DigitalswitchingcontrolmakesmaincircuitdigitalandDSPand/orMCUmakescontrollingsystem,digital.SoIGBTdrivingcircuit,asatieofmaincircuitandcontrollingsystem,shouldalsobegotdigitalized.Thus,adigitaldrivingcircuitbasedonoptocouplerdeviceHCPL-316Jisprovided.Sometestingexperimentsweredone.Afterdrivingtesting,thedrivingcircuitcertificatesthatdrivingwaveformssatisfytherequirementsofarcweldingpowersourceandthedrivingcircuitisreasonablyandsimplydesigned.Andthedrivingcircuithashighcontrollingprecisionandreliability.No-load-voltagetestingandweldingexternalcharacteristictestingprovethatthedrivingcircuitcanbeappliedinarcweldingpowersource.
简介:AnexperimentalsetupofacquiringthecoaxialvisualimageofthemoltenpoolandkeyholeinhighpowerNd:YAGlaserweldingisintroducedinthispaper.Itisoneofthemostdifficultproblemsinacquiringcoaxialimagethatthecoaxialimagingsignalofmoltenpoolandkeyholemustbeseparatedfromthelaserbeamwithhighpower.Thisproblemwasresolvedbydesigningadichroiticspectroscope.Thecharacteristicsofimagingsignalwereanalyzedandthecoaxialimageofmoltenpoolandkeyholewasacquired.Asmoothingfilterandahomomorphicfilterweredesignedtoremovethelowfrequencynoiseandtoenhancetheimageaccordingtothecharacteristicsofimagingsignal.Atlast,edgesofmoltenpoolandkeyholeweredetectedandextractedbasedonimagesegmentationwiththreshold.
简介:ThemicrostructuralevolutionandVickershardnessmeasurementintheweldingheat-affectedzone(HAZ)ofHD15Ni1MnMoNbCusteelfornuclearpowerstationwereinvestigatedbyGleeble-3180thermalmechanicalsimulator,andthesimulatedHAZcontinuouscoolingtransformationcurves(SH-CCT)weremeasuredsimultaneously.Witht_(8/5)increasingfrom3.75sto15000s,theproductwasobtainedmartensite,bainite,ferriteandpearlite,successively.TheresultofmicrostructureandVickershardnessintheheat-affectedzonewasingoodagreementwiththosemeasuredbySH-CCTdiagramwiththeheatinput16.2kJ/cmasanexampletoweldtheHD15Ni1MnMoNbCusteelpipeusingTIG/SMAW/SAWweldingmethods.
简介:Asimulationmodelisintroducedaboutthenon-linearityprocessofshort-circuitingtransferinCO2arcweldingfordisplayingtheinteractionbetweentheinverterpowersourceandweldingarcunderwaveformcontrol.Inthesimulationmodel,thefeedbacksignalsofcurrentandvoltagearetakenrespectivelyatthedifferentphaseinashortcircuitperiodictimeandappliedtothePWM(pulsewidthmodulation)moduleinamodelofinverterpowersourcetocontroltheoutputofpowersource.ThesimulationoperationaboutthedynamicprocessofCO2short-circuitingtransferweldingisimplementedonthefoundedsimulationmodelwithapeakarccurrentof400Aandapeakvoltageof35V,producingthedynamicarcwaveformswhichcanembodytheeffectofinverterharmonicwave.Thesimulatingwaveformsareclosetothatofweldingexperiments.