高低压无功补偿方法High and low voltage reactive power compensation method.docx

高低压无功补偿方法High and low voltage reactive power compensation method.docx

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高低压无功补偿方法Highandlowvoltagereactivepowercompensationmethod

高低压无功补偿方法（Highandlowvoltagereactivepowercompensationmethod）

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Inordertominimizethetransmissionlossofreactivepowerandimprovetheefficiencyofpowertransmissionanddistributionequipment,theconfigurationofreactivepowercompensationequipmentshouldbeinaccordancewiththeprincipleof"gradingcompensation,balancinginplace",andreasonabledistribution.

A,

（1）thecombinationofoverallbalanceandlocalbalanceismainlylocal.

（2）thecompensationofthepowersectoriscombinedwiththeusercompensation.

Inthedistributionnetwork,thereactivepowerconsumedbytheuseraccountsforabout50%to60%,andtheremainingreactivepowerisconsumedinthedistributionnetwork.Therefore,inordertoreducethetransmissionofreactivepowerinthenetwork,itisnecessarytorealizelocalcompensationandlocalbalanceasmuchaspossible,sothecompensationmustbemadebythepowersectoranduserstogether.

（3）thecombinationofdecentralizedcompensationandcentralizedcompensationismainlydecentralized.

Centralizedcompensationistoinstallalargercapacitycompensationcapacitorinthesubstation.Distributedcompensationreferstoreactivepowercompensationindispersedloadareassuchasdistributionlines,distributiontransformersandpowerequipmentforusers.Centralizedcompensationismainlytocompensatethereactivepowerlossofthemaintransformeritself,andtoreducereactivepowerofthetransmissionlineabovethesubstation,therebyreducingthereactivepowerlossofthepowersupplynetwork.Butitcannotreducethereactivepowerlossinthedistributionnetwork.Thereactivepowerrequiredbytheuserisdeliveredtotheloadthroughthedistributionlinebelowthesubstation.Therefore,inordertoeffectivelyreducelineloss,wemustdoreactivepowerwhereitoccurs,whereshouldbecompensated?

.Therefore,themediumandlowvoltagedistributionnetworkshouldbemainlydistributedcompensation.

（4）combininglossreductionwithpressureregulationtoreduceloss.

Two,themainfactorsaffectingthepowerfactor

ThegenerationofpowerfactorismainlyduetotheACpowerequipmentinthecourseofitswork,inadditiontotheconsumptionofactivepower,butalsotheneedforreactivepower.WhentheactivepowerPisconstant,ifthereactivepowerQisreduced,thepowerfactorcanbeimproved.Intheextremecase,whenQ=0,therateof=1.Therefore,theessenceofimprovingthepowerfactorproblemistoreducethereactivepowerrequirementofthepowerequipment.

2.1、asynchronousmotorandpowertransformerarethemainequipmentstoconsumereactivepower

Theairgapbetweenstatorandrotorofasynchronousmotoristhemainfactorthatdeterminestheasynchronousmotorneedsmorereactivepower.

Thereactivepowerofasynchronousmotoriscomposedoftwoparts:

reactivepowerunderno-loadandaddedvalueofreactivepowerundercertainload.Therefore,toimprovethepowerfactorofasynchronousmotor,itisnecessarytopreventtheno-loadoperationofthemotorandtoincreasetheloadrateasmuchaspossible.Themaincomponentofthetransformer'sreactivepowerisitsno-loadreactivepower,whichisindependentoftheloadrate.Therefore,inordertoimprovethepowerfactorofthepowersystemandtheenterprise,thetransformershouldnotrunwithoutloadorbeinalowloadrunningstate.

2.2,thepowersupplyvoltagebeyondtheprescribedrangewillalsohaveagreatimpactonthepowerfactor

Whenthesupplyvoltageishigherthantheratedvalueof10%,duetotheinfluenceofmagneticsaturation,reactivepowerwillgrowveryfast,accordingtotherelevantstatistics,whenthesupplyvoltageis110%oftheratedvalue,theGeneralFactoryofreactivepowerwillincreasebyabout35%.Whenthesupplyvoltageislowerthantheratedvalue,thereactivepowerisreducedaccordingly,sothattheirpowerfactorisimproved.Butthereductionofthepowersupplyvoltagewillaffectthenormaloperationoftheelectricalequipment.Therefore,measuresshouldbetakentokeepthepowersupplyvoltageofthepowersystemasstableaspossible.

2.3,thefluctuationofpowernetworkfrequencywillalsoaffectthemagnetizingandreactivepowerofinductionmotorsandtransformers

Two

.4,discussessomemainfactorsinfluencingpowerfactorinelectricpowersystem,itisnecessarytoseeksomeeffectiveandabletomakesomepracticalmethodsoflow-voltagepowernetworktoimprovethepowerfactor,makediyawangcanrealizethebalanceofreactivepower,

Achievetheeffectofreducinglossandenergysaving.

Three、reactivepowercompensationmethodinlowvoltagedistributionnetwork:

A.stochasticcompensation

Therandomcompensationistoconnectthelowvoltagecapacitorsetwiththemotorandswitchitthroughthecontrol,protectiondeviceandmotoratthesametime.Therandomcompensationisapplicabletothereactivepowerconsumptionofthecompensatedmotor,andthereactivepowerismainlybasedontheexcitationexcitation.Thismethodcanrestrictthereactivepowerloadofthepowerunit.

Theadvantagesofrandomcompensation:

whenthepowerequipmentisrunning,thereactivepowercompensationisputintouse,andwhenthepowerequipmentisstopped,thecompensationequipmentisalsoexited,andthecompensationcapacityisnotfrequentlyadjusted.Theutilitymodelhastheadvantagesoflowinvestment,smalloccupation,easyinstallation,convenientandflexibleconfiguration,simplemaintenance,lowaccidentrate,etc..

B.followercompensation

Followercompensationmeansthatthelowvoltagecapacitorisconnectedtothetwosideofthedistributiontransformerthroughlow-voltageinsurance,soastocompensatetheno-loadreactivepowercompensationofthedistributiontransformer.Withchangeinlightloadorno-loadreactiveloadisthemainloadexcitationtransformerreactivepowerdistributiontransformerno-loadreactivepoweristhemainpartoftheelectricityunitreactiveload,forlightloaddistribution,thispartofthelossaccountedforalargeproportionofsupply,resultingintheincreaseofelectricityprice.

Withtheadvantagesofcompensation:

simplewiring,convenientmaintenanceandmanagement,caneffectivelycompensatethetransformerno-loadreactivepowerlimits,reactivepowerbaseload,sothatthepartialreactivepowerbalance,soastoimprovetheutilizationrateofdistributiontransformer,reducethelossofreactivepower,

Withhigheconomicefficiency,itisoneofthemosteffectivemethodstocompensatereactivepower.

C.trackingcompensation

Trackingcompensationmeansthatthereactivepowercompensationswitchingdeviceisusedasthecontrolandprotectiondevice,andthecompensationmethodofthelow-voltagecapacitorbankiscompensatedonthe0.4kVbusofthelargeuser.Theutilitymodelissuitableforusersofspecialdistributiontransformer100kVAormore,andcanreplacethetwocompensationmodesofrandomandfollower,andthecompensationeffectisgood.

Theadvantageoftrackingcompensationisthattherunningmodeisflexible,theoperationandmaintenanceworkissmall,andtheservicelifeislongerandtheoperationismorereliablethantheformertwokindsofcompensationmethods.Priorityshouldbepaidtotrackingcompensation.

Four、reactivepowercompensationofHVdistributionnetwork:

One

Thenationalpowercompanyissuedontheelectricpowerindustrytocreatefirst-classfile,10kVpowerfactorisnotlessthan0.9,thelossislessthan5%,andthequalityofvoltageandreactivepowercompensationoperationmanagement,oneofthekeyproblemsofthemainsolution,istheinputcapacitorsinthe10kVline,usingfixedorautomaticphaseaccordingtotheinputmodetorealizereactivepowercompensation.Ifthecapacitorisfixedonapowersupplylineisgenerallylow,accordingtolineloadcalculation,automaticcompensationamountiscalculatedinlinewiththefullloadvalue,alinewithfixedandautomaticcompensationintwoways,youcanachievethedesiredeffect.

Two

Theprincipleofreactivecompensationisinplacebalance,accordingtotheactualsituationofruralpowerdistributionnetworkismorecomplex,

Itcannotbeunifiedmode,soweshouldadoptthemethodofcombinationofdispersionandcentralization,fixedandautomatic,whichiscarriedoutinthreesteps.First,thefixedcompensationcapacitorbankisinstalledatabout15%ofthemaintransformercapacityinthesubstation.Thetwoistofixthefixedcapacitorbankatthelineloadcenterorsomewhereaccordingtothereactivedemandwhentheloadislow.Thethreeistoinstallanautomaticcompensationcapacitorbankontheuppersideofthelineloadcenter.

3.forthe10kVdistributionnetworksystemmainlyusedinruralpowernetwork,completereactivecompensationshouldincludecentralizedcompensationofsubstation,10

KVlinecompensationandusersidelowvoltagecompensation,plusrandom