电力电子装置及系统 课件全套 Topic 1-Course Introduction and Power Semiconductor Devices-Topic 9-Modular multilevel converter

Topic1:IntroductionandSemiconductorDevicesCourseOutlinePowerSemiconductorDevices11.CourseOutlineCourseDescriptionAcourseontheanalysis,simulationanddesignofpowerelectronicssystems,whichisdesignedforthefourth-yearundergraduatestudents.CourseGoalsSelf-directedlearning.Studentsneedbuildandpracticeself-learningability.Academicreportwriting.Studentswouldbeabletomanageacademicwritingrules,basicreportstructure,andwritingskills.Professionalpresentationaddressing.Thatstudentsareinvitedtodeliverapublicspeechwouldprovideanopportunitytoforgetheirthoughtandbuildconfidence.21.CourseOutlineLectureTopicsPowerSemiconductorDevices(2hrs)Reviewofbasic4kindsofpowerconversion(2hrs)Reviewofdifferentapplications(2hrs)Multi-pulsedioderectifiers(3hours)Two-levelvoltagesourceinverter(4hrs)MultilevelcascadedH-bridgeinverter(4hrs)Multilevelneutralpointclampedinverter(4hrs)Pulse-width-modulationcurrentsourceinverter(3hrs)Modularmultilevelconverter(3hrs)Team-basedprojects(5hrs)31.CourseOutlineCourseOrganizationLecture:2hoursperweekSelf-learning:4hoursperweek(review,teamwork)ReferencebooksHigh-PowerConvertersandACDrives,byB.WuTransformerlessPhotovoltaicGrid-ConnectedInverters,byHuafengXiao,andXiaobiaoWangPowerConversionandControlofWindEnergySystems,byB.Wu,Y.Lang,N.ZargariandS.KouroHVDCTransmission:PowerConversionApplicationsinPowerSystems,byChan-KiKim,VijayK.Sood,Gil-SooJang,Seong-JooLim,Seok-JinLee41.CourseOutlineDesignProjects12-pulseand18-pulseDiodeRectifiersSpaceVectorModulationforTwo-levelVSIMultilevelCascadedH-BridgeInvertersMultilevelDiodeClampedInvertersPWMTechniquesforCurrentSourceConverters51.CourseOutlineSimulationTool-Matlab/SimulinkToinstallMatlab/Simulinkonyourlaptoporhomecomputer,pleasefollowtheinstructionpostedatwebsiteNote:ThiscoursedoesnotteachSimulink.InordertodotheDesignProjectssuccessfully,studentsneedasolidbackgroundandskillsinMatlab/Simulink.61.CourseOutlineProjectRequirementsTeam:groupof3or4studentsProjectreports:onereportperproject(withclearmarksofeachstudents’contribution)Projectpresentation:onespeakerperproject(Englishpreferred)ReportFormat:-Coverpage-Abstract-Introduction-Mainbody:Theoreticalanalysis,designandsimulation-Conclusions-Appendix:Simulinkdiagrams71.CourseOutlinePresentation(PPT)Format:-Coverpage-ApplicationBackground-RequirementsAnalysis-ProposedSolution-TheoreticalAnalysis-SimulationResultandDiscuss-Conclusion82.PowerSemiconductorDevicesPowerDiodeSiliconControlledRectifier(SCR)ThyristorGateTurn-OffThyristor(GTO)IntegratedGateCommutatedThyristor(IGCT)InsulatedGateBipolarTransistor(IGBT)SwitchSeriesOperation92.PowerSemiconductorDevicesDeviceRating10PowerDiode114500V/800Apresspackand1700V/1200AmodulediodesPowerDiodeHeatsinkAssemblyPresspackdevice:•Doublesidedcooling•Lowassemblycostandhighpowerdensity•Preferredchoiceforhighvoltagehighpowerapplications12PowerDiodeHeatsinkAssembly13SCRThyristor144500V/800Aand4500V/1500ASCRsSCRThyristorSwitchingCharacteristics15SCRThyristorMainSpecifications1612000V/1500ASCRThyristorGateTurn-Off(GTO)Thyristor174500V/800Aand4500V/1500AGTOsGateTurn-Off(GTO)ThyristorSymmetricalversusAsymmetricalGTOs18GateTurn-Off(GTO)ThyristorSwitchingCharacteristics19GateTurn-Off(GTO)ThyristorMainSpecifications204500V/4000AAsymmetricalGTOThyristorIntegratedGateCommutatedThyristor(GCT)216500V/1500ASymmetricalGCTGCT=ImprovedGTO+IntegratedGate+Anti-parallelDiode(optional)IntegratedGateCommutatedThyristorGCTClassifications22IntegratedGateCommutatedThyristorSwitchingCharacteristics23IntegratedGateCommutatedThyristorMainSpecifications246000V/6000AAsymmetricalGCTInsulatedGateBipolarTransistor(IGBT)251700V/1200Aand3300V/1200AIGBTInsulatedGateBipolarTransistor(IGBT)IGBTCharacteristics26StaticV-ICharacteristicsSwitchingcharacteristicsMainSpecificationsInsulatedGateBipolarTransistor(IGBT)273300V/1200AIGBTDeviceSeriesOperationCauseofVoltageImbalance28DeviceSeriesOperationEqualVoltageSharing29DeviceSeriesOperationActiveOvervoltageClamping(AOC)30•SuitableforseriesIGBTs•NotapplicabletoGCTs•Assumption:S1isturnedoffearlierthanS2•VCE1isclamedtoVmduetoactiveclamping.DeviceSeriesOperation31•PrototypeatSoutheastUniversity(High-powerIGBTdrivers)DCbusDriverboardInductorIGBTSummary3233Thanks3435363738Topic2:Reviewofbasic4kindsofpowerconversionAC-DCRectifiersDC-ACInvertersDC-DCConvertersAC-ACTransformers39WhatispowerelectronicsforAtypicalpowerconversionequipmentinmotordrivesystem40Fromapowerformtoanotherform,suchasDC,AC,amplitude,frequency.1.AC-DCRectifiers411.AC-DCRectifiers421.AC-DCRectifiers432.DC-ACInverters442.DC-ACInverters453.DC-DCConverters463.DC-DCConverters474.AC-ACTransformers484.AC-ACTransformers49Summary50Thepurposeofpowerelectronicsistoconvertapowerformtoanotherone.AC-DCrectifiersaretheearliestconversionneedDC-DCconvertershavethebiggestnumberoftopologiesDC-ACinvertersarethemostpopularneedinmodernindustry.Thiscourseisgoingtofocusonthiscategory.

51Topic3:ReviewofdifferentapplicationsVariableSpeedDriveRenewableEnergySystemPower/UtilityIndustryConclusion52ConverterPowerRating53•ElectricDriveSystems:100MW•RenewableEnergySystems:6MW•PowerSystemsFACTS:300MVAHVDC:3000MWFACTS-FlexibleACTransmissionSystemHVDC-HighVoltageDCTransmission1.VariableSpeedDriveApplications54ApplicationAreasSource:Robicon1.VariableSpeedDriveApplications55100MWWindTunneldriveSource:ABB-Application:NASAwindtunnel-Motor:Six-phase,synchronous-Load:Highpowerfan-SpeedRange:360-600rpm1.Supplysystem2.Transformer3.Converters4.Motor5.Excitationsystem6.Filter1.VariableSpeedDriveApplications56100MWWindTunneldriveSource:ABBOneofthe4convertersusedinthedrive•Invertertype:

currentsource•Switchingdevice:

SCRthyristor•#ofdevicesinseries:

12•Total#ofdevices:

(12x6)x4=288•Converterefficiency:

>99%1.VariableSpeedDriveApplications57100MWWindTunneldriveSource:ABBSix-phasesynchronousmotor(100MW,12.5KV,2.8KA)1.VariableSpeedDriveApplications58Source:FujiElectricHighSpeedTrain1.VariableSpeedDriveApplications59Source:FujiElectricHighSpeedTrainRectifier:Single-phasethree-leveldiodeclampedInverter:Three-phasethree-leveldiodeclampedRatings:1.1MW,1850V1.VariableSpeedDriveApplications60Source:KinderMorganCanadaInc.MegawattDriveforPipelinePumpsLength:1,150kmPipeSize:24”and30”Capacity:225,000bpdPumpstations:102.ApplicationsinWindEnergySystems61WindTurbineConfiguration2.ApplicationsinWindEnergySystems62WindGeneratorPowerRatingSource:NationalRenewableEnergyLaboratory2.ApplicationsinWindEnergySystems63WindGeneratorSize2.ApplicationsinWindEnergySystems64PermanentMagnetSG•Nogearbox,directdriven•CompletelydecoupledfromgridSource:ABBMotors&Drives,Finland2.ApplicationsinWindEnergySystems65Examples–MultibridM5000(5MWPMSG)Converter:ALSPAVDM7000Source:Alstom3.ApplicationsinPower/UtilityIndustry66FACTS-FlexibleACTransmissionSystems-StaticSynchronousCompensator(STATCOM)-StaticSynchronousSeriesCompensator(SSSC)-UnifiedPowerFlowController(UPFC)CustomPowerDevices-DynamicVoltageRestorer(DVR)-DistributionStaticSynchronousCompensator(D-STATCOM)-ActivePowerFilter(APF)HVDC–HighVoltageDCTransmission3.ApplicationsinPower/UtilityIndustry67STATCOM:StaticSynchronousCompensatorDVR:DynamicVoltageRestorerActiveFiltersSSTS:Solid-StateTransferSwitchSSCB:Solid-StateCircuitBreakerBESS:BatteryEnergyStorageSystem3.ApplicationsinPower/UtilityIndustry68STATCOMSource:ToshibaElectricPurpose:Toprovidereactivepowerforvoltageregulation3.ApplicationsinPower/UtilityIndustry6950MVASTATCOMSource:ToshibaElectricCapacity:50MVA(12.5MVA×4)DCVoltage:16.8kVConverterType:3phase3-pulsePWMGTO:6kV/2.5kAInsulating:Air;Cooling:Water3.ApplicationsinPower/UtilityIndustry70Example–100MVAGCTSTATCOMTalega±100MVA,138kVSTATCOMsystem3.ApplicationsinPower/UtilityIndustry71UPFCCombinesSTATCOMandSSSCwhicharecoupledviaacommonDClinkAllowsbi-directionalflowofrealpowerbetweentheSTATCOMandSSSCwithoutexternalenergysourceControlspowerflow,voltageandpowerfactor,allowingoptimaluseofexistinglines3.ApplicationsinPower/UtilityIndustry72Example–320MVA138kVUPFC(GTOBased)UPFCEquipmentGTOvalvehallSource:AEPInezUPFCProject3.ApplicationsinPower/UtilityIndustry73DynamicVoltageRestorer(DVR)Source:ABB3.ApplicationsinPower/UtilityIndustry74DynamicVoltageRestorer(DVR,4MVA)Source:ABB3.ApplicationsinPower/UtilityIndustry75HVDCSource:ABBMainBenefitsofHVDC•Longdistance•Networkstability•Lowlosses•Environmentalconcerns3.ApplicationsinPower/UtilityIndustry76HVDCSource:ABBHVDCConverterStation3.ApplicationsinPower/UtilityIndustry77HVDCTransmissionQuébec-NewEnglandSource:ABBMAINDATACommissioningyear:1990-1992Powerrating:2000MWDCvoltage:±450kVLengthofoverheadDCline:1,480kmMainreasonforchoosingHVDC:Longdistanceasynchronousnetworks3.ApplicationsinPower/UtilityIndustry78HVDCTransmissionQuébec-NewEnglandSource:ABBRadissonConverterStation3.ApplicationsinPower/UtilityIndustry79HVDCProjectinChina(1)Source:ABB3.ApplicationsinPower/UtilityIndustry80HVDCProjectinChina(1)Source:ABB3000MWHVDCfromThreeGorgestoGuangdong3.ApplicationsinPower/UtilityIndustry81HVDCProjectinChina(1)Source:ABB3000MWHVDCfromThreeGorgestoGuangdongOverviewThyristorvalvehallLengthofoverheadDCline:940km3.ApplicationsinPower/UtilityIndustry82HVDCProjectinChina(2)3-TerminalProjectinNanAoIslandCommissionedinDecember2013Summary83Powerelectronicsequipmentsarewidelyusedindifferentareas,whichisthecoreofelectrization.Chinaisthebiggestmarketforpowerelectronicsequipmentsnextdecades.

84Topic4:Multi-pulsedioderectifiersSix-pulseDiodeRectifierSeries-type12-,18-and24-pulserectifiersSeparate-type12-,and18-pulserectifiers85Multi-pulseDiodeRectifiers86WhyUseMultipulseDiodeRectifiers?•ToreducelinecurrentTHD;•Toimproveinputpowerfactor;and•Toavoidsemiconductordevicesinseries.Six-pulseDiodeRectifier87ResistiveLoadSupplyVoltages:Six-pulseDiodeRectifier88WaveformsSix-pulseDiodeRectifier89CapacitiveLoadAssumption:Six-pulseDiodeRectifier90Waveforms—DiscontinuousdccurrentSix-pulseDiodeRectifier91Waveforms—ContinuousdccurrentQ:Howtomakedccurrentcontinuous?A:1)IncreaseLs,2)Increaseloadcurrent.Why?Six-pulseDiodeRectifier92DefinitionofTotalHarmonicDistortion(THD)Phasevoltage(puresine):Linecurrent(distorted):RMSlinecurrent:LinecurrentTHD:Six-pulseDiodeRectifier93Per-phaseaverage(real)power:Per-phaseapparentpower:Totalpowerfactor(PF):Distortionfactor(DF):Displacementpowerfactor(DPF):PF=f(THD)DefinitionofPowerFactor(PF)Six-pulseDiodeRectifier94PerUnitSystemRatedpower,ratedlint-to-linevoltage:Basevoltageandfrequency:Basecurrentandimpedance:Baseinductanceandcapacitance:ExampleRectifierratings:4160V,60Hz,2MVA.Basecurrent=277.6A,Baseinductance=22.9mH.Lineinductance=2.29mH=0.1puLinecurrent=138.8A=0.5puSix-pulseDiodeRectifier95TypicalWaveforms/HarmonicContentSix-pulseDiodeRectifier96THDandPF12-pulseSeries-typeDiodeRectifier97RectifierTopologySeriestype:Twosix-pulserectifiersareinseriesattheoutput.Phaseshiftingtransformer:Secondaryline-to-linevoltage:Turnsratio:12-pulseSeries-typeDiodeRectifier98SimplifiedBlockDiagram12-pulsedioderectifiersimplifieddiagram12-pulseSeries-typeDiodeRectifier99WaveformsandFFT•No5thor7thharmonicsinthelinecurrent.•PrimarylinecurrentTHD:8.38%12-pulseSeries-typeDiodeRectifier100THDandPFComparisonwithsix-pulserectifier:THDisreduced;and

PFisimproved.18-pulseSeries-typeDiodeRectifier101RectifierTopologyPhase-Shifting(Zigzag)Transformer18-pulseSeries-typeDiodeRectifier102SimulatedWaveforms•No5th,7th,11th,or13thharmonicsinthelinecurrent.•Lowestharmonic:17th•LinecurrentTHD:3.06%18-pulseSeries-typeDiodeRectifier103MeasuredWaveforms18-pulseSeries-typeDiodeRectifier104THDandPFComparisonwith12-pulserectifier:improvedTHD24-pulseSeries-typeDiodeRectifier105RectifierTopologyPhase-Shifting(Zigzag)Transformer24-pulseSeries-typeDiodeRectifier106TypicalWaveforms•Lowestlinecurrentharmonic:23th•THD:1.49%24-pulseSeries-typeDiodeRectifier107THDandPF12-pulseSeparate-typeDiodeRectifier108RectifierTopology•SeparateTypeEachsix-pulserectifierfeedsaseparatedcload.12-pulseSeparate-typeDiodeRectifier109ApplicationExamplePhaseShiftingTransformerMultilevel(5-level)CascadeH-bridgeInverterFedDrive12-pulseSeparate-typeDiodeRectifier110ApplicationExample6kV11-levelCascadeH-bridgeInverterFedDrive12-pulseSeparate-typeDiodeRectifier111ApplicationExample11-levelCascadeH-bridgeInverterFedDrive(4160V,7.5MW)12-pulseSeparate-typeDiodeRectifier112TypicalWaveforms•Comparisonwithseries-type: -DCcurrentripple:higher -LinecurrentTHD:close12-pulseSeparate-typeDiodeRectifier113MeasuredWaveforms12-pulseSeparate-typeDiodeRectifier114LineCurrentTHDandInputPF18-pulseSeparate-typeDiodeRectifier115RectifierTopology18-pulseSeparate-typeDiodeRectifier116SimulatedWaveforms18-pulseSeparate-typeDiodeRectifier117LineCurrentTHDandInputPF24-pulseSeparate-typeDiodeRectifier118LineCurrentTHDandInputPF119Thanks120121Topic5:Two-levelvoltagesourceinverter122VDM5000Two-levelVSITopic5:Two-levelvoltagesourceinverter123•SinusoidalPWM•SpacevectormodulationLectureContentsBipolarSPWMforFullBridgeInverters124Topic5:Two-levelvoltagesourceinverter125WhyUsePWMTechniques?•Tocontrolinverteroutputfrequency(fundamental)•Tocontrolinverteroutputvoltage(fundamental)•TominimizeharmonicdistortionSinusoidalPWM126InverterConfigurationAssumption:dccapacitorverylargedcvoltageripplefreeSinusoidalPWM127ModulatingandCarrierWaves•vcr–Carrierwave(triangle)•vm–Modulatingwave(sine)•Amplitudemodulationindex•FrequencymodulationindexSinusoidalPWM128GateSignalGenerationvg1andvg4arecomplementary.SinusoidalPWM129Line-to-LineVoltagevABSinusoidalPWM130WaveformsandFFT•ma=0.8,mf=15,fm=60Hz,fcr=900Hz•Switchingfrequencyfsw=fcr=900HzSinusoidalPWM131HarmonicContent•Loworderharmonicsn<(mf-2)areeliminated•VAB1versusmaislinear•VAB1,max=0.612

VdSinusoidalPWM132Over-Modulation•Fundamentalvoltage↑•Low-orderharmonics↑SinusoidalPWM133ThirdHarmonicInjectionPWM•-Fundamentalvoltageincreased•-Noloworderharmonicsproduced•3rdharmonic–zerosequence(toappearinvANandvBN)•NotriplenharmonicsinvAB(vAB=vAN-vBN)SpaceVectorModulation134SwitchingStatesSpaceVectorModulation135SwitchingStates(Three-Phase)•EightswitchingstatesSpaceVectorModulation136SpaceVectorDiagram•Activevectors:to(6,stationary,notrotating)•Zerovector:(2)•Sixsectors:ItoVISpaceVectorModulation137SpaceVectors•Three-phasevoltages(1)•Two-phasevoltages(2)•Spacevectorrepresentation(3)

(2)(3)(4)whereSpaceVectorModulation138SpaceVectors(example)•Switchingstate[POO]S1,S6andS2

ON

and(5)(5)(4)(6)Similarly,

(7)

SpaceVectorModulation139ActiveandZeroVectors•ZeroVector:1•Redundantswitchingstates:[PPP]and[OOO]SpaceVectorModulation140ReferenceVectorVref•Definition

•Rotatinginspaceatω(8)•Angulardisplacement

(9)

SpaceVectorModulation141RelationshipBetweenVrefandVAB•Vrefisapproximatedbytwoactiveandazerovectors•Vrefrotatesonerevolution,VABcompletesonecycle•LengthofVrefcorrespondstomagnitudeofVABSpaceVectorModulation142DwellTimeCalculation•Volt-SecondBalancing

(10)•Ta,TbandT0–dwelltimesforand•Ts–samplingperiod•Spacevectors

and(11)(11)(10)(12)

SpaceVectorModulation143DwellTimeSolve(12)

(13)

SpaceVectorModulation144VrefLocationversusDwellTimesSpaceVectorModulation145ModulationIndex(15)

(16)

SpaceVectorModulation146ModulationRange•Vref,max

(17)(17)(16)•ma,max=1

•Modulationrange:

0

≤ma≤

1(18)SpaceVectorModulation147SwitchingSequenceDesign•BasicRequirement:Minimizethenumberofswitchings

persamplingperiodTs•Implementation:Transitionfromoneswitchingstatetothenextinvolvesonlytwoswitchesinthesameinverterleg.SpaceVectorModulation148Seven-segmentSwitchingSequence•Selectedvectors:

V0,V1andV2•Dwelltimes:

Ts=T0+Ta+Tb•Totalnumberofswitchings:6SpaceVectorModulation149UndesirableSwitchingSequence•VectorsV1andV2

swapped•Totalnumberofswitchings:10SpaceVectorModulation150SwitchingSequenceSummary(7–segments)Note:Theswitchingsequencesfortheoddandevensectorsaredifferent.SpaceVectorModulation151SimulatedWaveformsf1=60Hz,fsw=900Hz,ma=0.696,Ts=1.1msSpaceVectorModulation152WaveformsandFFTSpaceVectorModulation153WaveformsandFFT(Measured)SpaceVectorModulation154WaveformsandFFT(Measured)(f1=60Hzand

Ts=1/720sec)SpaceVectorModulation155Even-OrderHarmonicEliminationType-Asequence(startsandendswith[OOO])Type-Bsequence(startsandendswith[PPP])SpaceVectorModulation156Even-OrderHarmonicEliminationSpacevectorDiagramSpaceVectorModulation157Even-OrderHarmonicEliminationMeasuredwaveformsandFFTSpaceVectorModulation158Even-OrderHarmonic(f1=60Hzand

Ts=1/720sec)SpaceVectorModulation159Five-segmentSVMSpaceVectorModulation160SwitchingSequence(5-segment)SpaceVectorModulation161SimulatedWaveforms(5-segment)

f1=60Hz,fsw=600Hz,ma=0.696,Ts=1.1ms•Noswitchingfora120°periodpercycle.•Lowswitchingfrequencybuthighharmonicdistortion162ThanksTopic6:MultilevelcascadedH-bridgeinverter163CHBInverterFedDriveH-bridepowercellsSource:Toshiba-GeneralElectricTopic6:MultilevelCHBinverterH-BridgeInverterCHBInverterTopologiesPhaseShiftedPWMLevelShiftedPWMPWMSchemeComparison164Topic6:MultilevelCHBinverter165WhyUseMultilevelInverters?•Toincreaseinverteroperatingvoltagewithoutdevicesinseries•TominimizeTHDwithlowswitchingfrequenciesfsw•ToreduceEMIduetolowervoltagestepsSwitchingfrequencyforhighpowerconverters:fsw=60Hz~1000HzMultilevelInverterTopologies166Per-PhaseDiagramH-BridgeInverter167H-bridgePowerCellH-BridgeInverter168TypicalIndustrialApplicationsFive-levelCHBinverterH-bridgePowerCellH-BridgeInverter169BipolarModulationBipolarPWM:vABfrom-Vdto+Vdorfrom+Vdto-VdH-BridgeInverter170BipolarModulation(FFT)H-BridgeInverter171UnipolarModulation(1)•Twomodulationwavesvmandvm-•Onecarrierwavevcr•UnipolarPWM:vABfrom0to+Vdorfrom0to-VdH-BridgeInverter172UnipolarModulation(2)•Onemodulationwaves:vm•Twocarrierwave:vcr

andvm-CHBInverterTopologies173Five-LevelCHBInverterComplementarySwitchpairs:S11andS41;S31andS21;S12andS42;S32andS22;Note:Convertersincascade,butnoswitchingdevicesinseries.CHBInverterTopologies174OutputVoltageandSwitchingStatus(five-level)WaveformofvANiscomposedoffivevoltagelevels:2E,E,0,-E,and-2E.CHBInverterTopologies175Seven-andNine-LevelInverters(Perphasediagram)CHBInverterTopologies176UnequaldcBusVoltagesCHBInverterTopologies177UnequaldcBusVoltages(Two-cellseven-leveltopology)PhaseShiftedPWM178CarrierBasedPWM–PhaseShifted•#ofvoltagelevels:m=7•#ofcarriers:mc=m-1=6•Phaseshift:360°/mc=60°CarriersforH1bridge: vcr1andvcr1-CarriersforH2bridge: vcr2andvcr2-CarriersforH3bridge: vcr3andvcr3-m=7PhaseShiftedPWM179InverterWaveforms(7-level,phaseshifted)•Switchingoccursatdifferenttimes•fsw(device)=60mf=600Hz•Inverterphasevoltagelevels:7•LowEMI•Line-to-linevoltagelevels:13•Closetoasinusoid•LowTHDPhaseShiftedPWM180FFT(7-level,phaseshifted)•Lowestharmonics:around2mf•Lowestharmonics:around6mf•ContainingtriplenHarmonics•Notriplen

harmonics•Equivalentfsw(inverter)=60(6mf)=3600HzPhaseShiftedPWM181HarmonicContent(7-level,phaseshifted)LevelShiftedPWM182CarrierBasedPWM–LevelShifted•#ofvoltagelevels:

m=5•#ofcarriers:

mc=m-1=4Note:IPDprovidesthebestharmonicprofile.IPD:APOD:POD:LevelShiftedPWM183GatingArrangement(7-level)•#ofvoltagelevels:m=7•#ofcarriers:mc=m-1=6•fsw(device):-notequaltofcr,and-notthesameforallswitches.•Deviceconductionangle:-notequal.•Necessarytoswapswitchingpattern.LevelShiftedPWM184InverterOutputVoltages(7-level)•m=7•Switchingoccursatdifferenttimes•fsw(device)=fcr/mc=600Hz(avg)•vABclosetoasinusoid•LowTHD,lowEMI•fsw(inv)=fc=3600HzLevelShiftedPWM185PrototypeatRyerson(7-levelCHB)LevelShiftedPWM186MeasuredWaveforms(IPD,7-levelCHB)InverterphasevoltagevANLine-to-linevoltagevABPWMSchemeComparison187PWMatLowma•Atma=0.2:-PhaseshiftedPWM:THD=96.7%-LevelshiftedPWM:THD=48.8%PWMSchemeComparison188TotalHarmonicDistortion(THD)PWMSchemeComparison189SummaryTopic7:MultilevelNeutralPointClampedInverter190Three-LevelNPCInverterBasedMVDriveSource:ABB(ACS1000)Topic7:MultilevelNPCInvertersThree-levelNPCInverterSpaceVectorModulationNeutralPointVoltageControlHigh-levelNPCInverters191MultilevelInverterTopologies192Per-PhaseDiagramMultilevelNPCInverters193InverterConfigurationClampingdiodes:DZ1andDZ2(PhaseA)MultilevelNPCInverters194SwitchingStateComplementarySwitchpairs:S1andS3;S2andS4;MultilevelNPCInverters195GateSignalArrangementsInverterphasevoltagevAZhasthreelevels:E,0and–EMultilevelNPCInverters196InverterOutputWaveformsSpaceVectorModulation197SpaceVectors•Three-phasevoltages

(1)•Two-phasevoltages(2)•Spacevectorrepresentation(3)(2)(3)

(4)whereSpaceVectorModulation198SpaceVectors(Example)Switchingstate[POO]on-stateswitches:PhaseA:uppertwoswitches[P]PhaseB:middletwoswitches[O]PhaseC:middletwoswitches[O]Fromwhich

and

(5)•Substituting(5)to(4)givesaspacevector(6)Totalswitchingstates:27Totalspacevectors:19SpaceVectorModulation199SpaceVectorsDiagram19spacevectors:Zerovector:V0Smallvectors:V1–V6Mediumvectors:V7–V12Largevectors:V13–V18SpaceVectorModulation200SwitchingStatesandSpaceVectorsRedundancy:Zerovector–threeswitchingstatesSmallvectors–twostatespervectorSpaceVectorModulation201SwitchingStatesandSpaceVectorsNoredundantswitch