3Phase Power Factor Correction Using Vienna Rectifier Approach and Modular Construction for Improv.docx
- 文档编号:8195523
- 上传时间:2023-01-29
- 格式:DOCX
- 页数:13
- 大小:297.96KB
3Phase Power Factor Correction Using Vienna Rectifier Approach and Modular Construction for Improv.docx
《3Phase Power Factor Correction Using Vienna Rectifier Approach and Modular Construction for Improv.docx》由会员分享,可在线阅读,更多相关《3Phase Power Factor Correction Using Vienna Rectifier Approach and Modular Construction for Improv.docx(13页珍藏版)》请在冰豆网上搜索。
3PhasePowerFactorCorrectionUsingViennaRectifierApproachandModularConstructionforImprov
3-PhasePowerFactorCorrection,UsingViennaRectifierApproachandModularConstructionforImprovedOverallPerformance,EfficiencyandReliability
Mr.AbhijitD.Pathak,Mr.RalphE.Locher,Prof.HimanshuS.Mazumdar,
SeniorApplicationsEngineer,Director,ApplicationsEngineering,Head,ComputerScienceLab.,
IXYSCorp.,SantaClara,CAIXYSCorp.,SantaClara,CAPhysicalResearchLaboratory,
U.S.A.U.S.A.Ahmedabad-380009,INDIA
1.0Abstract:
Whileapplicationsfor1-PhasePFCarenowfamiliarandprevalent,thesameisnotthecasewith3-PhasePFC.Manyequipmentsusingkilowattsofpowerfrom3-Phasemainsshouldbecandidatesof3-Phasepowerfactorcorrection,becauseseveraladvantagesensue,bothtotheuseroftheequipmentandtotheutility.TheViennaRectifierapproachtoachieve3-Phasepowerfactorcorrectionoffersmanyadvantagesandconvenient,user-friendlyfeaturesascomparedtothetwo-level,six-switchboostPWMRectifier.Amongstthemare:
continuoussinusoidalinputcurrentswithunitypowerfactorandextremelylowdistortion;noneedforaneutralwire;reductioninvoltagestressandswitchinglossesofpowersemiconductorsbyalmost40%;immunitytowardsvariationorunbalanceinmains3-Phasevoltagesorabsenceofoneofthephases;widemainsvoltagerange:
320VACto575VAC;verylowconductedcommon-modeEMI/RFI;veryhighefficiencyoftheorderof97.5%,say,forpowerlevelsof10KWandinputlinevoltageof400VACandshortcircuitimmunitytofailureofcontrolcircuit.ThepaperdescribestheViennaRectifier’spowerstageandcontroltechniques,withparticularemphasisonmodularconstruction.WhatisproposedinthispaperisanewapproachofemployingFuzzyLogicforbuildingcontrollerforViennaRectifierDCBModulesfor3-PhaseACtoDCpowerconversion.
2.0Overview
Inthepastdecade,thereisgrowingawarenessaboutlinepollutionanddeterioratingpowerfactorduetoallpervadinginductiveandnon-linearloads.Utilitiesareasmuchconcernedastheusers.Passivepowerfactorcorrectiontechniquesareneitherconvenientnoreconomical;theyneedbulkycomponentsandarenotadaptivetochangingneeds.Althoughmanysolutionswereofferedfor1-Phasepowerfactorcorrection,3-Phaseactivepowerfactorcorrectionwasseldomconsidered.Asallhighpowerequipmentsderiveelectricalpowerfrom3-Phasemains,incorporatinganactive3-PhasePFCfrontendcancontributesignificantlyinimprovingoverallpowerfactorandreducinglinepollution.
Inadditiontoloweringpowerbilltotheconsumers,improvedpowerfactoralsocontributestowardsconservationofenergyandhelpsinreducingairpollution,byvirtueoflessfossilfuelrequiredforgeneratingsameamountofelectricalpower.OtherresultanteffectsarelowerI2Rlosses,steadierterminalVoltages,releasedsystemcapacityandreducedcable&switchgearsizes.ActivePFCfrontendsalsohelpmeettheIEEE519-92,IEC-555andEuropeanEN61000-3-2standardsforallowableharmoniccontentsofmains.
2.1Advantages
Althoughtherearesomepassiveandactive3-PhasePFCsolutions,ViennaRectifierisuniquebyvirtueofitsembodimentofseveraladvantages:
1.Itisa3-Phase,threelevelPWMrectifier,utilizingthreeMOSFETS,withcontrolledoutputVoltage;threewireinput,notrequiringanyconnectiontoNeutral.
2.ItisadualboosttypePFCwithcontinuoussinusoidalinputcurrentandunidirectionalpowerflow
3.Itneedsonlythreeactiveswitches,i.e.MOSFETS
4.ItisOperationaleveninpresenceofunbalancedmainsoronlytwophases.
5.Totalswitchinglossesarereducedbyafactorofsix,assumingswitchingfrequencybelow50KHz.
6.AnymalfunctionincontrolcircuitdoesnotmanifestitselfinshortcircuitofoutputorPFCfrontend.
7.SinusoidalinputcurrentswithPowerFactor=0.997,THD<5%andoverallefficiency>97%areobtainablewithcurrentdesigns.
Ascanbeseen,ViennaRectifieristhe3-PhasePFCsolutionthatneedstobefullyexploited.ReadymadeViennaPowerSemiconductormodules,embodyingMOSFETS+FREDStomakeastandaloneDirectCopperBondedPowerCircuit,makeitquiteconvenientanduser-friendly.Powerful,yetinexpensive,microcomputersandDSPsmakeitattractivetodesigncompactcontrollersfortheViennaRectifiers.
AnewapproachofemployingFuzzyLogicforbuildingembeddedcontrollerforViennarectifierfor3-PhaseACtoDCpowerconversionisproposedhere.
3.0Applications
Alargenumberofindustrial,telecomandcomputingequipmentsnowuse3-Phasemainspower.Salientamongstthemare:
1.A.C.andD.CDrives
2.TelecommunicationPowerSupplies
3.UninterruptiblePowerSupplies
4.AirConditioningUnits
5.LargeComputerInstallations
6.Powersuppliesforallindustrialusessuchaswelding,surfacetreating,motioncontrol,largeappliancesandprocesscontrol
7.R.F.TransmittersandRadarTransmittersandrepeaterstations
8.Regulatedandtracking+350Vand–350VDC,forhighpowerbidirectionalservoamplifiersfordrivingheavy-dutycriticalloadssuchasAntennaTrackingandPositioningsystems.
AlltheaboveandmanymoresuchsystemsaregoodcandidatesforusingViennaRectifiersforachievingperformanceimprovementsaspertheadvantageslistedin2.1.
4.0ViennaRectifier
4.1ModusOperandi
ViennaRectifierasshowninFigure1,wasoriginallydevelopedattheTechnicalUniversityVienna.Itcomprisesasemiconductorswitch,say,aMOSFETineachphaselegofa3-Phasediodebridge.ByadjustingthewidthofthepulsethatturnsONtheMOSFET,correspondinglinecurrentisforcedtobesinusoidalandinphasewiththeVoltage.WhentheMOSFETisturnedONthecorrespondingphaseisconnected,viathelineinductor,tothecenterpointbetweenthetwooutputcapacitors.Thephasecurrentrises,throughtheMOSFET,duringthatpulseperiod,chargingthecapacitor.WhentheMOSFETisturnedoff,currenttapersthroughthediodehalfbridge(upperorlowerdependingondirectionofthecurrentflow).
4.2ObjectiveofViennaRectifier
Itisahighlyefficientmethodofhighcurrent,3-PhaseACtoDCconversionandisparticularlyattractiveforachievingunitypowerfactoroperation.Infigure-1ACR,ACYandACBare440V,50Hz,3-PhasesinusoidallineVoltages.-Vdcand+VdcaretheDCoutputsconnectedtoload.Therearethreesemiconductorswitches,correspondingtoeachphaseT1,T2andT3.Theseareswitchedcontinuouslyataround25KHz.Theduty
Figure13-PhaseViennaRectifierConfiguration
CycleofthepwmswitchingissoprogrammedthatthecurrentdrawnfromeachphaseissinusoidalandinphasewiththecorrespondinglineVoltage,thusensuringnearunitypowerfactorandminimumtotalharmonicdistortion.
4.3Description
InViennaRectifierconfiguration,asshowninfigure-1,theoutputcapacitorissplitintwopartsastwoequalvaluecapacitors,C1andC2,connectedinseries.Acrosstheoutputcapacitorsthe–Vdcand+Vdcaredevelopedas3-Phasepeakdetectedoutputs.Aswitchforeachphaseisconnected,suchthatwhen“ON”,itconnectsthelinephasetothecenternodeofC1andC2throughaseriesinductance.Forashortswitchingperiod,(assuming10microseconds),thecapacitorschargelinearly.Thisoffsets-Vdcand+Vdc.Theoffsetdependsonthecorrespondingphasevoltageandtheswitch“ON”timeduration.ThecommonnodeofC1andC2willhaveVoltagewithtriangularwaveshape,havingthreetimesthemainsfrequencyanditsamplitudewillbeonequarterofthephasevoltage.
Figure23-Phaselinevoltagesred,yellowandbluewith12timesegments
From0through11
4.4ViennaRectifierModules
LookingatFigure1,itbecomesapparentthatifoneweretoassembletheentire3-PhaseViennaRectifierPFCcircuitusingdiscretecomponents,manydifferentpowersemiconductorshavetobeconnectedtogether.Thisisnotonlyinconvenientandcostly,butalsoinvolvesadegreeofvariationinperformancefromunittounit.Theleadinductancesandparasiticcapacitancemaytendtooscillate,makingitsoperationathighenoughswitchingfrequencyataskbyitself.
Fortunately,readymadeViennaRectifierpowermodulesareavailableinDCB(DirectCopperBonding)ceramicbaseplate.Thesehaveanumberofusefulattributes:
1.Thesemoduleshaveisolationvoltageof3600VoltsAC,ensuringpersonalandequipmentsafetyandareU/Lrecognized.Thereisnoneedforexternalisolation.
2.Extremelylowpackageinductance,facilitatinghighspeedswitching
3.Easytomountonaprintedcircuitboardforeitherwavesolderingormanualsoldering
4.KelvinsourceforreliabledriverconnectionsfortheMOSFETS
5.TheMOSFET,builtusingHDMOSprocesshaslowRDS(on)andRGintandlowRthJSandlowinputandoutputcapacitancesandlowgatechargeandrisefalltimesforlowconductionandswitchinglosses
6.FREDS(FastRecoveryEpitaxialDiodes)havelowVFandextremelylowtrr
7.Consistentandpredictableperformancefromunittounit
4.5AdvantagesofDCB
TheDirectCopperBondedsubstrateshaveanumberofveryattractivefeaturesasgivenbelow:
1.Theyhaveverygoodmechanicalstrength,holdstableshapewithgoodadhesionandarecorrosionresistant
2.Theyhaveverygoodthermalconductivity,enhancingheatdissipationtoheatsink.Thisallowsveryclosepackagingofchips,furtherreducingleadinductancesandtranslatingmorepowerperunitvolume.
3.Verygoodthermalcyclingcapability,givingreliableperformanceovermanyyears
4.Thethermalexpansioncoefficientisclosetothatofsiliconsonointerfacelayersarerequired
5.Theyfeaturegoodheatspreadingthusleavingnohotspotsduringactualoperati
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 3Phase Power Factor Correction Using Vienna Rectifier Approach and Modular Construction for Improv P
链接地址:https://www.bdocx.com/doc/8195523.html