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IPWMPWMPWMDSPBUCKBOOSTBUCK-BOOSTMATLABBUCKPWMSaberTMS320F2812DSPPWMDSPIIABSTRACTTheburn-intesthasbeenregardedasafeasibleapproachforqualitycertificationofnewACSourceproducts.Apassiveloadbankisgenerallyused,andsignificantenergyiswasted.Fromtheviewpointofenergyconservation,aloadconsumption-freemethodisneed.Withthedevelopmentofpowerelectronictechnology,anewACElectronicLoadbyreplacingtheconsumptionloadbankwithapulsewidthmodulation(PWM)converterispresent.Implementingthisnewidea,thetestingpowercanbesentbacktotheutilitysystemforreuse,andoffersmoreflexibility,enhancedreliability,lessspaceandlowercostthananassortmentofpassiveloads.ThearchitectureofACElectronicLoadstudiedinthisthesisconsistsoftwopowerstages.TheinputstagewhereavoltagesourcePWMrectifierisusedtoimitatetherequiredloadcharacteristic,suchasR,RLandRCloadcharacteristic.TheoutputstageisaPWMinverterwhichsendsbacktherecyclingenergytotheutility.DigitallycontrolledPWMconvertershavegainedincreasingattentionbecauseofanumberofpotentialadvantages.Oneofthemajorchallengingissuesindigitalcontrolistheundesiredlimit-cycleoscillationsduetothelackoftimeresolutioninthedigitalpulse-widthmodulator(DPWM)tosatisfyspecifiedoutputvoltageregulationaccuracy.TherelationshipbetweenDPWMresolutionandoutputvoltageregulationaccuracyisanalyzedforseveralbasicconvertersoperatingincontinuousconductionmode(CCM).TheminimumDPWMresolutionrequiredtopreventlimit-cycleoscillationisderived.TheconclusionsareverifiedbysimulationandexperimentalresultsbasedonadigitallycontrolledBUCKconverter.AnovelsolutionofconsumptiveACElectronicLoadsuitforfunctiontestofACSourceproductsisproposed.ThecontrolstrategyoftheACElectronicLoadwithenergyrecyclecapabilityisanalyzedandsimulatedwithSaber.Thedesignofpassivecomponentsinthepowerstageisstudied,especiallytheinductorintheinputstage.ATMS320F2812DSPbasedprototypeofACElectronicLoadisdesignedandimplemented.Simulationandexperimentalresultsconfirmthevalidityandeffectivenessofthepresentedsolution.Sincetheislandingofthegrid-connectedsystemscancausealossoflivesanddamagetoequipments,ithastobeavoidedbyaIIIreliabledetectionsystem.Ananti-islandingmethodbasedonpositivefeedbackconceptisdiscussedandvalidatedbysimulation.Keywords:ACElectronicLoad,VoltagesourcePWMRectifier,Burn-intest,DigitalControl,Limit-CycleOscillation,Anti-islandingDSPVIII1.1..................................................................................21.2[7]UPS................................................................31.3..................................................41.4..................................................41.5..........................................................52.1.....................................................................112.2PWM.............................................................................122.3ADC................................................132.4............................................................................142.5................................................................................152.6BUCK...................................................................162.7....................................................................................172.8....................................................................................172.9DPWMBUCK.....................................182.10DPWMBOOST.............................192.11DPWMBUCK-BOOST.........................192.12DPWM..........................................202.13BUCKMATLAB...........................................222.14BUCK.........................................................222.15..................................................................................232.16BUCK.................................................................243.1PWM.....................................................................................253.2PWM...............................................................263.3VSR.................................................................................273.4....................................................................283.5R........................................................................................283.6............................................................................293.7................................................................303.8............................................................30IX3.9....................................................................313.10..........................................................................323.1150Hz....................................333.12400Hz..................................344.1PWM.....................................................................................354.2VSR.......................................................364.3........................................................................374.490......................................................................374.5............................................................