Power inverterWord文档下载推荐.docx

Power inverterWord文档下载推荐.docx

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inverter,isan 

electricalpowerconverter 

thatchanges 

directcurrent 

（DC）to 

alternatingcurrent 

（AC）.[1] 

Theinputvoltage,outputvoltage,andfrequencyaredependentondesign.

Staticinvertersdonotusemovingpartsintheconversionprocess.Someapplicationsforinvertersincludeconverting 

high-voltagedirectcurrent 

electricutility 

linepowertoAC,andderivingACfromDCpowersourcessuchas 

batteries.

Contents

[hide] 

∙1 

Types

o1.1 

Outputwaveforms

▪1.1.1 

Modifiedsinewave

▪1.1.2 

Sinewave

o1.2 

Resonance

o1.3 

Gridtie

▪1.3.1 

Solar

∙2 

Applications

o2.1 

DCpowersourceutilization

o2.2 

Uninterruptiblepowersupplies

o2.3 

Inductionheating

o2.4 

HVDCpowertransmission

o2.5 

Variable-frequencydrives

o2.6 

Electricvehicledrives

o2.7 

Airconditioning

o2.8 

Electroshockweapons

∙3 

Circuitdescription

o3.1 

Basicdesigns

o3.2 

o3.3 

Advanceddesigns

o3.4 

Threephaseinverters

∙4 

History

o4.1 

Earlyinverters

o4.2 

Controlledrectifierinverters

o4.3 

Rectifierandinverterpulsenumbers

∙5 

Seealso

∙6 

References

o6.1 

Generalreferences

∙7 

Externallinks

Types[editsource 

| 

editbeta]

Staticinvertersuseswitchingdevicesarrangedinan 

Hbridge.Thelargeswitchingdevicesforpowertransmissionapplicationsinstalleduntil1970predominantlyused 

mercury-arcvalves.Invertersforconsumeruseaswellaspowertransmissionsystemscommissionedafter1970are 

solidstate.[2] 

Thesame 

Hbridge 

basicdesignisusedinsmaller-scaleconsumerdevicesaswell.[3]

Outputwaveforms[editsource 

Aninvertercanproducesquarewave,modifiedsinewave,pulsedsinewave,orsinewavedependingoncircuitdesign.Thetwodominantcommercializedwaveformtypesofinvertersasof2007aremodifiedsinewaveandsinewave.

Therearetwobasicdesignsforproducinghouseholdplug-involtagefromalower-voltageDCsource,thefirstofwhichusesaswitching 

boostconverter 

toproduceahigher-voltageDCandthenconvertstoAC.ThesecondmethodconvertsDCtoACatbatterylevelandusesa 

line-frequency 

transformer 

tocreatetheoutputvoltage.[4]

Modifiedsinewave[editsource 

Thewaveformincommerciallyavailablemodified-sine-waveinvertersisasquarewavewithapausebeforethepolaritytransition,whichonlyneedstocyclethroughathree-positionswitchthatoutputsforward,off,andreverseoutputatthepre-determinedfrequency.[4] 

Thepeakvoltageto 

RMS 

voltagedonotmaintainthesamerelationshipasforasinewave.TheDCbusvoltagemaybeactivelyregulatedorthe"

on"

and"

off"

timescanbemodifiedtomaintainthesameRMSvalueoutputuptotheDCbusvoltagetocompensateforDCbusvoltagevariation.

TheratioofontoofftimecanbeadjustedtovarytheRMSvoltagewhilemaintainingaconstantfrequencywithatechniquecalled 

PWM.Harmonicspectrumintheoutputdependsonthewidthofthepulsesandthemodulationfrequency.Whenoperatinginductionmotors,voltageharmonicsisnotofgreatconcern,howeverharmonicdistortioninthecurrentwaveformintroducesadditionalheating,andcanproducepulsatingtorques.[5]

MostACmotorswillrunonMSWinverterswithanefficiencyreductionofabout20%duetotheharmoniccontent.[dubious 

– 

discuss][6]

Aproposalsuggestedin 

PowerElectronics 

magazineutilizestwovoltagesasanimprovementoverthecommoncommercializedtechnologywhichcanonlyapplyDCbusvoltageineitherdirectionsorturnitoff.Theproposaladdsanadditionalvoltagetothisdesign.Eachcycleconsistsofsequenceas:

v1,v2,v1,off/pause,-v1,-v2,-v1.[7]

Sinewave[editsource 

Asinewaveinverterproducesasinewaveoutput,witha 

totalharmonicdistortion 

under3%[citationneeded].Sinewaveinvertersaremorecomplexandhaveahighercostthanamodified-sine-wavetypeofthesamesize.[7]

Resonance[editsource 

Mainarticle:

Resonantinverter

Resonant 

invertersproducesinewaveswith 

LCcircuits 

toremovetheharmonicsfromasimplesquarewave.Typicallythereareseveralseries-andparallel-resonantLCcircuits,eachtunedtoadifferentharmonicofthepowerlinefrequency.Thissimplifiestheelectronics,buttheinductorsandcapacitorstendtobelargeandheavy.Itshighefficiencymakesthisapproachpopularinlarge 

uninterruptiblepowersupplies 

indatacentersthatruntheinvertercontinuouslyinan"

online"

modetoavoidanyswitchovertransientwhenpowerislost.

Acloselyrelatedapproachusesaferroresonanttransformer,alsoknownasa 

constantvoltagetransformer,toremoveharmonicsandtostoreenoughenergytosustaintheloadforafewACcycles.Thispropertymakesthemusefulin 

standbypowersupplies 

toeliminatetheswitchovertransientthatotherwiseoccursduringapowerfailurewhilethenormallyidleinverterstartsandthemechanicalrelaysareswitchingtoitsoutput.

Gridtie[editsource 

Grid-tieinvertersaredesignedtofeedintotheelectricpowerdistributionsystem.Theytransfersynchronouslywiththelineandhaveaslittleharmoniccontentaspossible.Theyalsoneedameansofdetectingthepresenceofutilitypowerforsafetyreasons,soasnottocontinuetodangerouslyfeedpowertothegridduringapoweroutage.

Solar[editsource 

Asolarinvertercanbefedintoacommercialelectricalgridorusedbyanoff-gridelectricalnetwork.Solarinvertershavespecialfunctionsadaptedforusewith 

photovoltaic 

arrays,includingmaximumpowerpointtrackingandanti-islanding 

protection.

Applications[editsource 

DCpowersourceutilization[editsource 

Inverterdesignedtoprovide115VACfromthe12VDCsourceprovidedinanautomobile.Theunitshownprovidesupto1.2amperesofalternatingcurrent,orenoughtopowertwosixtywattlightbulbs.

AninverterconvertstheDCelectricityfromsourcessuchas 

batteries, 

solarpanels,or 

fuelcells 

toACelectricity.Theelectricitycanbeatanyrequiredvoltage;

inparticularitcanoperateACequipmentdesignedformainsoperation,orrectifiedtoproduceDCatanydesiredvoltage.

Micro-inverters 

convertdirectcurrentfromindividualsolarpanelsintoalternatingcurrentfortheelectricgrid.Theyaregridtiedesignsbydefault.

Uninterruptiblepowersupplies[editsource 

An 

uninterruptiblepowersupply 

（UPS）usesbatteriesandaninvertertosupplyACpowerwhenmainpowerisnotavailable.Whenmainpowerisrestored,a 

rectifier 

suppliesDCpowertorechargethebatteries.

Inductionheating[editsource 

InvertersconvertlowfrequencymainACpowertohigherfrequencyforusein 

inductionheating.Todothis,ACpowerisfirst 

rectified 

toprovideDCpower.TheinverterthenchangestheDCpowertohighfrequencyACpower.

HVDCpowertransmission[editsource 

With 

HVDC 

powertransmission,ACpowerisrectifiedandhighvoltageDCpoweristransmittedtoanotherlocation.Atthereceivinglocation,aninverterina 

staticinverterplant 

convertsthepowerbacktoAC.Theinvertermustbesynchronizedwithgridfrequencyandphaseandminimizeharmonicgeneration.

Variable-frequencydrives[editsource 

variable-frequencydrive

variable-frequencydrive 

controlstheoperatingspeedofanACmotorbycontrollingthefrequencyandvoltageofthepowersuppliedtothemotor.Aninverterprovidesthecontrolledpower.Inmostcases,thevariable-frequencydriveincludesa 

sothatDCpowerfortheinvertercanbeprovidedfrommainACpower.Sinceaninverteristhekeycomponent,variable-frequencydrivesaresometimescalledinverterdrivesorjustinverters.

VFDsthatoperatedirectlyfromanACsourcewithoutfirstconvertingittoDCarecalled 

cycloconverters.Theyarenowcommonlyusedonlargeshipstodrivethepropulsionmotors.

Electricvehicledrives[editsource 

Adjustablespeedmotorcontrolinvertersarecurrentlyusedtopowerthe 

tractionmotors 

insome 

electric 

diesel-electric 

railvehiclesaswellassome 

batteryelectricvehicles 

hybridelectric 

highwayvehiclessuchasthe 

ToyotaPrius, 

BYDe6 

FiskerKarma.Variousimprovementsininvertertechnologyarebeingdevelopedspecificallyforelectricvehicleapplications.[8] 

Invehicleswith 

regenerativebraking,theinverteralsotakespowerfromthemotor（nowactingasagenerator）andstoresitinthebatteries.

Airconditioning[editsource 

Inverterairconditioning

Aninverter 

airconditioner 

usesa 

tocontrolthespeedofthemotorandthusthecompressor.

Electroshockweapons[editsource 

Electroshockweapons 

tasers 

haveaDC/ACinvertertogenerateseveraltensofthousandsofVACoutofasmall9VDCbattery.Firstthe9VDCisconvertedto400–2000VACwithacompacthighfrequencytransformer,whichisthenrectifiedandtemporarilystoredinahighvoltagecapacitoruntilapre-setthresholdvoltageisreached.Whenthethreshold（setbywayofanairgaporTRIAC）isreached,thecapacitordumpsitsentireloadintoa 

pulsetransformer 

whichthenstepsituptoitsfinaloutputvoltageof20–60kV.Avariantoftheprincipleisalsousedin 

electronicflash 

bugzappers,thoughtheyr