Switching Power Supply开关电源外文翻译资料Word下载.docx
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Switchingpowersupplyisavoltageconversioncircuit,themainworkisthestep-upandstep-down,arewidelyusedinmodernelectronicproducts.Alwaysworkbecausetheswitchingtransistorinthe"
on"
and"
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state,socalledswitchingpowersupply.Switchingpowersupplyinrealtermsisanoscillatorcircuit,theconversionofelectricalenergynotonlyusedinpowercircuit,thecircuitinotherapplicationsarealsocommon,suchasLCDbacklightcircuits,suchasfluorescentlamps.Switchthesourcecomparedwiththetransformerhighefficiency,goodstability,smallsizeandotheradvantages,disadvantagesistherelativelysmallpower,andhigh-frequencyinterferenceonthecircuit,circuitcomplexity,suchaseasymaintenance.
Talkingaboutswitchingpowersupplybeforeyoufamiliarwiththefeedbackoscillatorcircuittransformer,canproducearegularpulsecurrentorvoltageofthecircuitiscalledoscillationcircuit,transformerfeedbackoscillatorcircuitisabletomeettheseconditionsthecircuit;
itinthebasicamplifiercircuitwithafeedbackloopcomposedofC2,L1electiontoformaparallelresonantfrequencycircuit,theinstantaneouspowerinthecircuitturn-VT,thistimeintheC2,L1,composedofparallelresonantcircuitshaveaveryrichharmonic,whentheplusparallelresonancefrequencyandthenaturalfrequencyofthesamecircuit,thecircuittoenterastateofoscillation,andVTthroughL3feedbacktofurtherenlargethebase,andultimatelytheformationofaregularpulsecurrentorvoltageoutputtotheloadRL.Switchingpowersupplyisaroundthetransformerandthefeedbackoscillatorcircuitdesign,butthebasisoftheoriginalincreaseinthenumberofprotectionandcontrolcircuits,analysisofouroscillationcircuitcanbeusedtoanalyzethemethodofswitchingpowersupply.
SwitchingPowerSupplyvibrationbywayofsub-swingcanbedividedintoself-excitedanditexcitedthetwo,sincethereisnoneedforplus-excitedself-oscillationsignalsource,sincetheexcitationcanseeitasafeedbackoscillatorcircuittransformer,anditisexcitedistotallydependentontheoutsidetomaintaintheoscillation,inthepracticalapplicationofself-excitationofacomprehensiverangeofapplications.Accordingtothestructureofincentivessignalclassification;
canbedividedintopulse-width-modulatedpulseamplitudemodulationandtwopulse-width-modulatedsignaltocontrolthewidth,thatis,frequency,pulseamplitudemodulationcontrolsignalofthemagnitudeoftheroleofthetwothesamesothatoscillationfrequencyismaintainedatwithinacertainrange,totheeffectofvoltagestability.Windingtransformercanbedividedintothreetypesingeneral,agroupinvolvedintheprimarywindingoftheoscillation,agroupistomaintaintheoscillationofthefeedbackwinding,thereisagroupoftheloadwindings.Householdappliancesusedinswitchingpowersupply,aftertheACto220Vbridgerectifier,convertedintoabout300VDC,filterintothetransformerisaddedaftertheswitchtohigh-frequencyoscillationsofthecollector,feedbackwindingbacktothebasetomaintaintheoscillationcircuit,loadsensorwindingsoftheelectricalsignal,byrectification,filtering,theDCvoltageregulatorhasbeentoprovidepowertotheload.Windingintheprovisionofelectricpowerload,butalsotakeupthecapacityofvoltagestability,thetheoryisthenacircuitvoltageoutputvoltagesamplingdevicestomonitortheoutputvoltagechanges,timelyfeedbacktoadjusttheoscillationfrequencyoscillatorcircuittoachievethevoltagestabilityThepurposeofthecircuitinordertoavoidinterference,thefeedbackvoltagetotheoscillatorcircuitwillbeisolatedoptocoupler.Mostswitcheshaveastandbypowercircuit,switchingpowersupplyinstandbymodestilloscillating,butthefrequencyofnormalworkinghoursthanlower.
Someswitchingpowersupplyarecomplex,numerouscomponents,manyprotectionandcontrolcircuit,intheabsenceoftechnicalsupport,maintenanceisaheadachewiththematter.Ifacethiskindofsituationis,firstofall,Iwillfindtheswitchanditsparticipationintheexternaloscillationcircuit,itseparatedfromthecircuittoseeifitmettheconditionsforoscillation,suchasdetectionbiasandwhetheritisnormal,whetherpositivefeedbackfailure,aswellasitsownswitches,switchingpowersupplyhasverylargeprotection,afterexclusionoftheprosecutionandloadcontrolandprotectioncircuit.thecontrolcircuitwhileoutputfromthesample,withthesetstandards,thencontrolledinverter,changeitsfrequencyorpulsewidthoutputachievestability,ontheotherhand,accordingtotestdataprovidedbythecircuitbycircuitprotectionidentification,Controlcircuitfortheunitforvariousprotectionmeasures.
Improvethepowerdensityoftheswitchingpowersupply,makeitsmall,lightweight,peopleconstantlystriveforthegoal.Thehigh-frequencypowersupplyisoneofthehotspotsofinternationalpowerelectronicssector.Theminiaturizationofthepower,toreducetheweightofportableelectronicdevices(suchasmobilephones,digitalcameras,etc.)isparticularlyimportant.Thespecificmeasurestoenabletheminiaturizationoftheswitchingpowersupply:
First,highfrequency.Inordertorealizethepowerofhighpowerdensity,wemustimprovetheoperatingfrequencyofthePWMconverter,whichreducesthesizeoftheweightofenergystoragecomponentsinthecircuit.
Thesecondistheapplicationofpiezoelectrictransformer.Theapplicationofpiezoelectrictransformerenableshigh-frequencypowerconverterstoachievealight,small,thinandhighpowerdensity.Piezoelectrictransformerusingpiezoelectricceramicmaterialsuniquevoltagetransform-Vibration"
and"
vibration-voltagetransformthenatureofthetransmissionenergy,theequivalentcircuitasaseriesandparallelresonantcircuit,isoneofthefocusesoftheresearchinthefieldofpowerconversion
Third,usingthenewcapacitor.Inordertoreducethesizeandweightofpowerelectronicsequipment,mustfindwaystoimprovethecapacitorperformance,increaseenergydensity,andresearchanddevelopmentofnewcapacitorsaresuitableforuseinpowerelectronicsandpowersystemsrequirelargeamountofcapacitance,equivalentseriesresistanceESRsmallvolumeandsmall.
Powersystemalargenumberofmagneticcomponents,materials,structureandpropertiesofhigh-frequencymagneticcomponentsaredifferentfromthepowerfrequencymagneticcomponents,therearemanyissuesneedtobestudied.High-frequencymagneticcomponentsusedinmagneticmaterialshavethefollowingrequirements:
loss,goodthermalperformance,superiormagneticproperties.Inthemegahertzfrequencymagneticmaterialofconcernforpeople,thenano-crystallinesoftmagneticmaterialsdevelopmentandapplicationofall.
Highfrequency,inordertoimprovetheefficiencyofswitchingpowersupplymustbedevelopedandtheapplicationofsoft-switchingtechnology.Itisahotresearchtopicintheinternationalpowersectorinthepastfewdecades.
Thesoft-switchingconverterforlowvoltage,highcurrentoutputtofurtherimprovetheefficiencyofthemeasureistryingtoreducetheswitchon-stateloss.SuchassynchronousrectifierSRtechnology,thepowerMOStubereversediodeasarectifierwithswitch,insteadoftheSchottkydiode(SBD),canreducethepipepressuredrop,soastoimproveefficiency.
Suitablefordistributedpowersystemsusedforhighspeedintegratedcircuitcomposedofalargeworkstation(suchasimageprocessingstation),thelargepowerofdigitalelectronicexchangesystems,etc.,theadvantagesare:
thecomponentsofmodularDC/DCconverter;
easytoachieveN+1powerredundancy,easyamplificationofloadcapacity;
canreducecurrentandvoltageonthe48Vbusdrop;
easytoachieveuniformthermaldistribution,easeofthermaldesign;
transientresponse;
availableonlinetoreplacetheinvalidmodule.
Distributionpowersystem,therearetwotypesofstructure,oneoftwostructure,andtheotherisatertiarystructure.
AC/DCconversioncircuitinputrectifiercomponentsandfiltercapacitorintheinputsinusoidalvoltage,single-phaserectifierpowersupplyofelectronicequipment,powerfactorofthegridside(ACinput)isonly0.6to0.65.PFC(PowerFactorCorrection)converter,theline-sidepowerfactorto0.95and0.99,theinputcurrentTHDislessthan10%.Bothgovernanceharmonicpollution,butalsoimprovestheoverallefficiencyofthepowersupply.ThistechniqueisknownasactivepowerfactorcorrectiontheAPFCsingle-phasetheAPFCdomesticandinternationaldevelopmentearlier,thetechnologyismoremature;
three-phasetypeoftopologyandcontrolstrategyofAPFCAlthoughtherearemany,buthaveyettocontinueresearchanddevelopment.
GenerallyhighpowerfactorAC/DCswitchingpowersupply,composedbythetwotopologyforlow-powerAC/DCswitchingpowersupply,twotopologyoverallefficiencyofthelowandhighcost.
Inputpowerfactorrequirementsarenotparticularlyhigh,thecombinationofthePFCconverterandafter-classDC/DCconverterintoatopology,constitutesasingle-stagehighpowerfactorAC/DCswitchingpowersupply,onlyoneofthemainswitch,canPowerFactorCorrectiontoabove0.8,andadjustableoutputDCvoltage,thistopologyiscalledthesingle-tubesingle-stageS4PFCconverter.
Thevoltageregulatormoduleisalowvoltage,highcurrentoutputDC-DCconvertermoduleprovidespowertothemicroprocessor.
Thespeedandefficiencyofdataprocessingsystemsisincreasing,andthelogicvoltagemustbereducedinordertoreducetheelec