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1、Copeland9-124921-12229-1249ApplicationEngineeringBulletinAE-1249-R9RevisedDecember,1994POWERFACTORCORRECTIONFormanyyearselectricutilitiesandlargeindustrialschematicallyinFigures1and2.Thenumberofplantshavereducedelectricalcurrentdemandsbycyclespersecondisreferredtoasthefrequencytheuseofcapaci
2、torstoincreasethepowerfactoron(hertz).largeelectricalloads.WiththegrowingemphasisonThevalueswhichwemeasureforvoltageandtheneedtoconserveelectricalenergy,thereisamperageinacircuitareactuallymeanvaluesoccur-increasinginterestinpowerfactorcorrectionforringduringthecycle.three-phasemotors,evenon
3、smallinstallations.Ifthevoltageandamperageareinphase,asinElectricalFundamentalsFigure3,thepowerconsumed(watts)isequaltotheThestudyofelectricalengineeringtheoryisproductofthevoltstimesamps.If,however,thevolt-extremelycomplex.Fortunately,thepracticalappli-ageandamperageareoutofphase,asinFigure
4、4,thecationofelectricityinvolvesexactscientificrelation-productofvoltstimesampsisonly“apparentpower”shipsthatfollowprecisephysicallaws,sotheapplica-(volt-amperes),andtheactualpower(watts)issometionengineerneedsbeconcernedonlywithbasiclesservalue,thereductionbeingdeterminedbytheformulasandrel
5、ationships.degreetowhichcurrentandvoltageareoutofphase.Tounderstandpowerfactor,areviewofelectricalPowerfactorisdefinedastheratioofthepowerfundamentalsmaybehelpful.consumeddoingwork(watts)dividedbytheappar-entpower(volts-amperes).Indirectcurrentcircuits,Voltistheelectricalunitofmeasurementuse
6、dtosincethereisnoreversalofvoltageorcurrent,theexpresstheelectricalpotentialorforcewhichcausespowerfactorineffectisalwaysunity.Inalternatingcurrentflow.currentcircuitswithlaggingcurrent(causedbyinductiveloads),theactualpoweravailableforworkisAmpereisthetermusedtoexpresstherateoftheproductoft
7、hevoltstimesamperestimestheelectricalfloworcurrent.powerfactor.Wattisusedtoexpressthepowerconsumed.ElectricalFormulasOhmisusedtoexpresstheresistancetoflowofThefollowingbasicformulasgoverntherelation-currentinacircuit.shipofvoltage,amperage,andpower