动态无功补偿新型控制策略分析

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1、上海交通大学硕士学位论文whichhasthecapabilitytoinjectorabsorbreactivecurrents.Inthispaper,twotypesofSTATCOMtopologies,namely,threesingle-phaseSTATCOMandthree-phasefour-wireSTATCOMareinvestigated.Inordertoovercomethedeficienciesofthepoorharmonicdetectionprecisionandtheunsatisfactoryperformanceofthecon

2、ventionaldoubleclosed-loopproportional-integralcontrollers,anewcurrent-loopcontrollerisproposedforthethreesingle-phaseSTATCOMs,whichcombinestheconventionalPIregulatorsandtheresonantcontrollers.Extensivesimulationresultsundervariousloaddisturbancescenariosdemonstratethattheproposedcontrols

3、trategyhasexcellentperformanceswithimprovedharmonicrejectioncapabilityandperfectgrid-sidecurrents.Asforthethree-phasefour-wireSTATCOMtopologies,thethree-dimensionalpulse-widthmodulationschemeisadoptedandthemathematicalmodelinstationaryα-β-0coordinatesisderived.Besides,theperfectharmonicco

4、mpensation(PHC)strategyisproposedtoensurestableoperationoftheSTATCOMundergridvoltageunbalanceand/orharmonics.Thedecoupleddoublesynchronousreferenceframephase-lockedloop(DDSRF-PLL)isutilizedforphasesynchronizationoftheSTATCOM.Bydecouplingthevectorofgridvoltagesintopositive-andnegative-sequ

5、encecomponents,fastpositive-sequencecomponentestimationforthegridvoltagescanbeachieved,evenunderseveregridvoltageunbalanceand/harmonics.Thesimulationresultsdemonstratethatthethree-phasefour-wireSTATCOMwithDDSRF-PLLcanprovideaccuratecompensationperformancefortheunbalancedloadbycompensating

6、thezero-sequenceandAbstractnegative-sequencecomponentsofloadcurrents,andalsoprovidesatisfactoryperformanceundergridvoltagesunbalanceand/orharmonics.Finally,acost-effectivesoluationforreactivecompensationisproposedbythecombinedTSCandSTATCOMmethodology.Thecoordinatedoperationofthesetwodevic

7、esisrealizedbyproperlyselectionofthereferencecompensationcurrentsforindividualdevice.ThevalidityandeffectivenessoftheproposedcompensationschemeisverifiedbythesimulationresultsobtainedfromMatlab/Simulink.Keywords:reactivepowercompensation;thyristorswitchedcapacitor(T