简介:本文阐述了单周控制Buck—Boost电路的单相交流AC/AC电压转换的工作原理,并利用Maflab/Simulink软件对该转换电路建模并进行仿真,给出了稳态及负荷突变情况下的仿真结果,证明在原理上是可行的,静、动态性能良好。此外,通过分析认为,可将所使用全控型开关元件的一半,用半控型晶闸管替代,从而可能降低设备的成本。
简介:Inordertorealizethemodulardesignofthemicrogrid,thispaperproposedanewmodulartopologyfortheAC-DCmixedmicrogrid.Inthattopology,theACmicrogridunitandtheDCmicrogridunitwerepackagedtogetherbytheback-to-backconverter.Thebattery-supercapacitorhybridenergystoragesystemwasconnectedtotheDCbusofback-to-backconverter.Bythereasonabledesignonthebattery-supercapacitorhybridsystem,theenergystoragesystemcouldsupplytherapidpowerandenergysupportforthemicrogridspontaneously.Themathematicalmodelandthecontrolalgorithmofthatmicrogridtopologywerestudied.Bythesimulationanalysis,itcanbeconcludedthatAC-DCmixedmodularmicrogridtopologycouldoperatesteadilyonboththegrid-connectedmodeandtheisolatedmode.Furthermore,wecanconcludebythesimulationthatthedesignedmodularmicrogridcouldoperateuninterruptedwhenthemicrogridtopologyswitchedfromthegrid-connectedmodetotheisolatedmode.Theseamlessswitchingbecamethenaturalpropertyforthemodularmicrogrid.Asaresult,themodularmicrogridtopologycanbeconsideredasausualpower/loadmoduletorealizethefriendlypowerinteractionwiththepowergrid.
简介:Thispaperpresentsanoveltransformermagneticbiasingcontrolmethodforhigh-powerhigh-performanceACpowersupplies.Seriousconsequencesduetomagneticbiasingandseveralmethodstoovercomemagneticbiasingarefirstdiscussed.Thecausesofthetransformermagneticbiasingarethenanalyzedindetail.Theproposedmethodisbasedonahigh-passfilterinsertedintheforwardpathandthefeedforwardcontrol.Withouttestingmagneticbiasingoftransformer,thismethodcaneliminatemagneticbiasingoftransformercompletelyinreal-timewaveformfeedbackcontrolsystemsthoughtheaeroerroroftheHalleffectsensorsvarieswithtimeandtemperature.Themethodhasalreadybeenemployedina90KVAACpowersupply.Itisshownthatitoffersimprovedperformanceoverexistingones.Inthismethod,nosensorsareusedsuchthatthezeroerroroftheHalleffectsensorshasnotanyinfluenceonthesystem.Itissimpletodesignandimplement.Furthermore,themethodissuitableforvariouspowerapplications.
简介:Soft-switchingtechniquesareattractivetounity-power-factorAC/DCconverterintheviewofthesizereductionandEMIsuppression.Asoft-switchedboostPFCconverterhasbeenstudiedbasedonitstopologyanalysis,PSIMsimulationandcircuitexperiment.Aspeciallimitationofsoft-switchingtechniqueshasbeenfoundintheirAC/DCapplications.
简介:Thisletterstudiesandanalyzestheworkingfeaturesofmaincircuitoftri-levelboostPowerFactorCorrect(PFC)converterandtheadvantagesoftri-levelswitchconverterinaspectsofbearinghigh-voltageofpowercomponents,overallsystemlossandmagneticcomponentselectionbaseduponthesingle-levelboostPFCswitchconverter.Besides,relyingontheapplicationofmi-croprocessorinpowerconvertertechnologyandDSP(DigitalSignalProcessing)chip'sstrongcal-culatingcapacity,theletterpresentstheadoptionofmodifiedschemeoftri-levelboostPFCconverterunderthecontrolofpredictivecontrolalgorithm.Moreover,theoperatingprincipleandcontrolmethodarespecified,theresultsofcircuittestandanalysisareprovidedandtheadvantagesofpre-dictivecontroltechnology-basedmulti-levelboostPFCconverterisverified.