Introduction
Powerelectronictechnologyisdividedintotwobranches:powerelectronicdevicemanufacturingtechnologyandvariablecurrenttechnology(rectification,inverter,chopping,frequencyconversion,andequalization).
Ithasnowbecomeanindispensableprofessionalbasiccourseformodernelectricalengineeringandautomationmajors,anditoccupiesanimportantpositionincultivatingthisprofessionaltalent.
ThenamePowerElectronicsappearedinthe1960s.In1974,W.NewelloftheUnitedStatesusedaninvertedtriangle(asshowninFigure1)todescribepowerelectronics,thinkingthatitwasformedbytheintersectionofthreedisciplinesofpower,electronics,andcontroltheory.Thisviewisgenerallyacceptedallovertheworld."Powerelectronics"and"powerelectronicstechnology"arecalledfromtwodifferentperspectives,academicandengineeringtechnology.
ItisgenerallybelievedthatthebirthofpowerelectronictechnologyismarkedbythefirstthyristordevelopedbyGeneralElectricCompanyoftheUnitedStatesin1957.Theconceptandfoundationofpowerelectronictechnologyisduetothethyristorandthyristorconvertertechnology.Establishedbydevelopment.Therehavebeenelectronictechnologiesforpowerconversionbefore,sotheperiodbeforetheemergenceofthyristorscanbecalledtheprehistoricordawnperiodofpowerelectronics.Inthelate1970s,fullycontrolleddevicesrepresentedbygateturn-offthyristors(GTO),powerbipolartransistors(BJT),andpowerfieldeffecttransistors(Power-MOSFET)developedatfullspeed(thecharacteristicsoffullycontrolleddevicesarethroughThecontrolofboththegateandthebaseofthegatecanbothturnitonandturnitoff).Makethefaceofpowerelectronicstechnologyanewlookandenteranewstageofdevelopment.Inthelate1980s,compositedevicesrepresentedbyinsulatedgatebipolartransistors(IGBTscanberegardedasthecombinationofMOSFETandBJT)integratedsmalldrivepower,fastswitchingspeed,smallon-statevoltagedrop,andgreatercurrent-carryingcapacity.Thesuperiorperformancemakesittheleadingdeviceofmodernpowerelectronictechnology.Inordertomakethepowerelectronicdevicecompactandreducethevolume,severalpowerelectronicdevicesandnecessaryauxiliarydevicesareoftenmadeintotheformofmodules.Later,thedrive,control,protectioncircuitsandpowerdevicesareintegratedtoformapowerintegration.Circuit(PIC).Atpresent,thepowerofPICisstillrelativelysmall,butthisrepresentsanimportantdirectionforthedevelopmentofpowerelectronicstechnology.
Thetechnologythatusespowerelectronicdevicestoachieveindustrial-scaleelectricalenergyconversionissometimescalledpowerelectronicstechnology.Undernormalcircumstances,itistoconvertoneformofindustrialelectricalenergyintoanotherformofindustrialelectricalenergy.Forexample,convertACpowertoDCpowerorconvertDCpowertoACpower;convertindustrialfrequencypowertopoweratthefrequencyrequiredbytheequipment;whennormalACpowerisinterrupted,useaninverter(seepowerconverter)toconvertTheDCpowerofthestoragebatteryistransformedintopowerfrequencyACpower.Theapplicationofpowerelectronictechnologycanalsorealizetheconversionbetweennon-electricenergyandelectricenergy.Forexample,solarcellsareusedtoconvertsolarradiantenergyintoelectricalenergy.Differentfromelectronictechnology,theelectricenergytransformedbypowerelectronictechnologyisusedasanenergysourceratherthanasacarrierforinformationsensing.Therefore,whatpeopleareconcernedaboutistheelectricpowerthatcanbeconverted.
Powerelectronicstechnologyisanemergingdisciplinebasedonthethreemajordisciplinesofelectronics,electricalengineeringandautomaticcontrol.Becauseitisahigh-powerelectricaltechnology,andmostofitservesindustriesthatapplystrongelectricity,itisoftenclassifiedasanelectrician.Thecontentofpowerelectronictechnologymainlyincludespowerelectronicdevices,powerelectroniccircuits,powerelectronicdevicesandtheirsystems.Powerelectronicdevicesusesemiconductorsasthebasicmaterial,andthemostcommonlyusedmaterialissinglecrystalsilicon;itstheoreticalbasisissemiconductorphysics;itsprocesstechnologyissemiconductordevicetechnology.Thetechnologyofmicroelectronicshasbeenwidelyusedinmodernnewpowerelectronicdevices.Powerelectroniccircuitshaveabsorbedthetheoreticalbasisofelectronics,andaccordingtothecharacteristicsofdevicesandtherequirementsofpowerconversion,manypowerconversioncircuitshavebeendeveloped.Thesecircuitsalsoincludevariouscontrol,trigger,protection,display,informationprocessing,relaycontactsandothersecondarycircuitsandperipheralcircuits.Usingthesecircuits,accordingtothedifferentapplicationobjects,formacompletemachineforvariouspurposes,calledpowerelectronicdevices.Thesedevicesoftenformasystemwithloadsandsupportingequipment.Technologiessuchaselectronics,electricalengineering,automaticcontrol,andsignaldetectionandprocessingareoftenwidelyusedinthesedevicesandtheirsystems.
Application
Generalindustry:
ACandDCmotors,electrochemicalindustry,metallurgicalindustry
Transportation:
Electrifiedrailways,electricvehicles,aviation,aerospace,navigation
Powersystems:
Highvoltagedirectcurrenttransmission,flexiblealternatingcurrenttransmission,reactivepowercompensation
ElectronicdevicesPowersupply:
Providepowerforinformationandelectronicdevices
Householdappliances:
"Energy-savinglamps",inverterairconditioners
Others:
p>UPS,aerospacevehicles,newenergy,powergenerationdevices
Function
(1)Optimizetheuseofelectricenergy.Throughtheprocessingofelectricenergybypowerelectronictechnology,theuseofelectricenergyisreasonable,efficientandeconomical,andtheoptimizationofelectricenergyuseisrealized.Forexample,intermsofpowersaving,asurveyof14aspectssuchasfanandwaterpump,electrictraction,rollingmillsmelting,lightindustrypapermaking,industrialkilns,inductionheating,electricwelding,chemicalindustry,electrolysis,etc.,showsthatthetotalamountofpotentialpowersavingisequivalenttothatofthecountryin199016%ofthepowergeneration,sothepromotionandapplicationofpowerelectronictechnologyisastrategicmeasureforenergysaving,andthegeneralenergysavingeffectcanreach10%-40%.mycountryhasincludedmanydevicesinthepromotionandapplicationofenergysavingprojects.
(2)Transformtraditionalindustriesanddevelopemergingindustriessuchasmechatronics.Accordingtotheforecastofdevelopedcountries,95%ofelectricenergywillbeprocessedbypowerelectronictechnologybeforebeingused.Thatis,95%ofvariouselectromechanicalequipmentforindustrialandcivilusearerelatedtothepowerelectronicindustry.Inparticular,powerelectronictechnologyisweakcurrent.Themediathatcontrolsstrongelectricityisanimportantinterfacebetweenelectromechanicalequipmentandcomputers.Itcreatesconditionsfortraditionalandemergingindustriestoadoptmicroelectronicstechnology,andbecomestheguaranteeandbasisfortheroleofcomputers.
(3)Thedevelopmentofhighfrequencyandfrequencyconversiontechnologyinpowerelectronicstechnologywillenableelectromechanicalequipmenttobreakthroughthetraditionalpowerfrequencyanddevelopinthedirectionofhighfrequency.Achievingthebestworkingefficiencywillreducethevolumeofelectromechanicalequipmentseveraltimes,dozensoftimes,theresponsespeedcanreachhighspeed,andcanadapttoanyreferencesignal,realizenoiselessandhavebrand-newfunctionsanduses.
(4)Theprogressofpowerelectronicsintelligence,toacertainextent,integratesinformationprocessingandpowerprocessing,andintegratesmicroelectronicstechnologyandpowerelectronicstechnology.Itsdevelopmentmaycausesignificantchangesinelectronictechnology.reform.Somepeopleevenproposedthatthenextrevolutioninelectronicswilloccurintheapplicationofelectronictechnologyforindustrialequipmentandpowergrids.Powerelectronicstechnologywillbringpeopletotheedgeofthesecondelectronicrevolution.
Devices
Thefirstglassmercuryarcrectifierappearedin1902.In1910,theiron-shellmercuryarcrectifierappeared.Theuseofmercuryarcrectifierstoreplacemechanicalswitchesandinvertersisthebeginningofpowerelectronicstechnology.Thecopperoxiderectifierwastrial-producedin1920,andtheseleniumrectifierappearedin1923.Inthe1930s,theserectifiersbegantobewidelyusedinpowerrectifierdevices.Transistorsappearedinthelate1940s.Intheearly1950s,transistorsdevelopedtowardshigh-power,andhigh-powerdiodesmadeofsemiconductorsinglecrystalmaterialswerealsodeveloped.In1954,theSwedishGeneralElectricCompany(ASEA)firstusedmercuryarctubesforhigh-voltagerectificationandinverters,andappliedthemon±100kVDCtransmissionlinestotransmit20MWofelectricity.In1956,AmericanJ.Mooremadetheprototypeofthyristor.In1957,AmericanR.A.Yorkmadeapracticalthyristor.Thyristorswereusedinpowerelectronicdevicesattheendofthe1950s,andtheyhavebeenrapidlypromotedsincethe1960s,andaseriesofderivativedeviceshavebeendevelopedtoexpandtheapplicationfieldsofpowerelectronictechnology.Withthepopularizationofthyristorapplications,powerelectroniccircuitshavedevelopedmanypowerelectroniccircuits.Accordingtotheirfunctions,theycanbedividedinto:①rectifiercircuitthatconvertsACpowerintoDCpower;②InvertercircuitthatconvertsDCpowerintoACpower;③AnACconversioncircuitthatconvertsoneformofACpowerintoanotherformofACpower;④ADCconversioncircuitthatconvertsoneformofDCpowerintoanotherformofDCpower.Thesecircuitsallcontainthyristors,andeachthyristorneedsacorrespondingtrigger.Asaresult,manytriggercontrolcircuitshaveappearedinconjunctionwiththesepowerelectroniccircuits.Accordingtothedevicesused,thesecontrolcircuitscanberoughlydividedintothreegenerations.Thefirst-generationcontrolcircuitwasmainlycomposedofdiscreteelectroniccomponents(suchastransistorsanddiodes).Itwasusedalotuntilthelate1980s.Thesecondgenerationconsistsofintegratedcircuits.Sincetheemergenceoftheworld'sfirstintegratedcircuitintheUnitedStatesin1958,thedevelopmenthasbeenextremelyrapid.Itisappliedtothecontrolcircuitofthepowerelectronicdevicetomakethestructurecompact,functionandreliabilityimproved.Thethirdgenerationiscontrolledbyamicrocomputer.Sincethe1970s,duetothedevelopmentofmicrocomputers,powerelectronicdeviceshavefurtherprogressedtowardstherealizationofintelligence.PowerelectronicdevicesWiththedevelopmentandimprovementofpowerelectroniccircuits,manytypesofpowerelectronicdevicescomposedofthyristorscontinuetoappear.Suchashigh-powerelectrolysispowersupply,weldingpowersupply,andelectroplatingDCpowersupply;DCandACtraction,DCdrive,ACcascadespeedregulation,frequencyconversionspeedregulationandothertransmissionpowersupplies;excitation,reactivepowerstaticcompensation,harmoniccompensationandotherpowerPowerelectronicdevicesusedinthesystem;lowfrequency,mediumfrequency,highfrequencypowersuppliesandothernon-powerfrequencypowersupplies,especiallyinductionheatingmediumandhighfrequencypowersupplies;uninterruptedpowersupplies,ACpowersuppliesandotherindustrialpowerelectronicpowersupplies;variousVoltageregulatorandsoon.Thesepowerelectronicdeviceshavehigherelectricalefficiencythantraditionalmotor-generatorsets(takeamotor-generatorsetwithacapacityof10kilowattstohundredsofkilowattsandafrequencyof1000Hzasanexample.Undertheratedload,theefficiencyη=80%,anddecreasesignificantlywiththedecreaseoftheload.Ifthethyristorpowersupplyisused,η≥92%,anddoesnotchangemuchwiththeload),therefore,thereisasignificantenergy-savingeffect.Thepowerelectronicdeviceisastaticdevicewithasmallfootprint,lightweightandeasyinstallation(takingtheweldingpowersupplyasanexample,comparedwiththerotaryweldingmachine,theweightisreducedby80%andtheenergysavingis15%).Atthesametime,powerelectronicdevicesareofteneasiertoadjustfrequency,voltage,etc.,respondquickly,havemultiplefunctions,andhaveahighdegreeofautomation.Therefore,theyareusedinindustrynotonlytosaveenergy,butalsotoimproveproductivityandproductquality,saverawmaterials,andoftenImprovetheworkingenvironment.However,mostofthepowerelectronicdevicesareelectronicswitchingdevices,whichoftenproduceharmonicinterferencetothepowergridandload,andsometimescausecertainhigh-frequencyinterferencetothesurroundingenvironment.Thismustbeproperlyaddressedwhendesigningthesedevicesandsystems(seehighSub-harmonicsuppression).
Progress
Fromthemid-1950stothelate1970s,powerelectronicsbasedonhigh-powersilicondiodes,bipolarpowertransistorsandthyristorapplications(especiallythyristors)Thetechnologydevelopmentisrelativelymature.Sincetheendofthe1970s,twodevelopmentshavecausedahugeimpactonpowerelectronicstechnology.Thefirstisthatthedevelopmentofmicrocomputershasplayedamajorroleinthecontrolsystem,faultdetection,andinformationprocessingofpowerelectronicdevices,andwillcontinuetodevelopinthefuture;thesecondisthatmicroelectronicsandopticalfibertechnologieshavepenetratedintopowerelectronicdevicesanddevelopedMorenewgenerationpowerelectronicdevices.Inadditiontothedevelopmentofordinarythyristors(6500V,3500A),thegate-offthyristor(GTO)voltagehasreached4500V,andthecurrenthasreached2500～3000A.Bipolartransistorsarealsomovingtowardslargercapacity.Inthemiddleandlate1980s,itsindustrialproductshadamaximumvoltageof1400voltsandamaximumcurrentof400amps.Theoperatingfrequencywasmuchhigherthanthatofthyristors.Thecurrentgaincouldreach75-200whentheDarlingtonstructurewasadopted.Withthedevelopmentofopticalfibertechnology,theUnitedStatesandJapansuccessivelydevelopedopticallycontrolledthyristorsbetween1981and1982andusedtheminDCpowertransmissionsystems.Comparedwiththeelectricallytriggeredthyristor,thislightcontroltubesimplifiesthetriggercircuit,improvestheinsulationlevelandanti-interferenceability,andenablesthedevelopmentoftheconverterequipmentinthedirectionofsmallandlightweight,whichnotonlyreducesthecost,butalsoimprovesthereliabilityofoperation.sex.Atthesametime,field-controlledpowerelectronicdeviceshavealsobeendeveloped.Forexample,powerMOSFETsandpowerstaticinductiontransistors(SIT)havereachedkilovoltsandvoltagesandcurrentsoftenstohundredsofamperes,andsmallandmedium-capacityoperationsThefrequencycanreachmegahertz.Anewgenerationofpowerelectronicdevicessynthesizedbyfieldcontrolandbipolar,suchasinsulatedgatebipolartransistor(IGTorIGBT)andMOScontrolledthyristor(MCT)arealsoemerging,andthecapacityhasalsobeenconsiderable.Thesenewdevicesallhavegateturn-offcapability,andtheoperatingfrequencycanbegreatlyimproved,makingpowerelectroniccircuitssimpler,andcontinuouslyimprovingthevolume,weight,efficiency,performanceandotherindicatorsofpowerelectronicdevices.ItwillenablepowerelectronicstechnologyDevelopmenttoarenewalstage.Atthesametime,thecomputersimulationandsimulationtechnologyofpowerelectronicdevices,powerelectroniccircuitsandpowerelectronicdevicesarealsoconstantlydeveloping.