High-frequencyswitchingpowerSupplycircuitofhighfrequencyswitchingpowersupplyfromthefollowingcomponents:first.amaincircuitfromtheexchangenetworkinput,DCoutputoftheentireprocess,including:animportfilter:itsroleistonetworktheclutterfiltration,butalsohinderedtheplaneoftheclutterfeedbacktothepublicgrid.2,rectifierandfilter:directACpowerrectifierforsmootherDC,forunderatransformation.3,theinverter:Rectifierthehighfrequencyalternatingcurrentintodirectcurrent,high-frequencyswitchingpowersupplyisthecorecomponentofthehigherfrequency,size,weightandoutputratiosmaller.4,andtherectifieroutputfilter:UnderloadtheneedtoprovidestableandreliableDCpowersupply.Second,thecontrolcircuitwhileoutputfromthesample,withthesetstandards,thencontrolledinverter,changeitsfrequencyorpulsewidthoutputachievestability,ontheotherhand,accordingtotestdataprovidedbythecircuitbycircuitprotectionidentification,Controlcircuitfortheunitforvariousprotectionmeasures.Third,inadditiontoprovidingdetectioncircuitprotectioncircuitisrunningvariousparameters,butalsoprovideinformationdisplayinstruments.Fourth,theauxiliarypowersupplycircuitforthesinglepowersupplytothedifferentrequirements.SwitchingregulatorcontrolprincipleSwitchingControlSwitchingRegulatorsKprincipletoacertaintimeintervalrepeatedlyconnectedanddisconnected,connectedtotheswitchK,InputvoltageEandKthroughswitchingcircuitfiltertoloadRL,theentireswitchconnected,PowerEtoprovideenergyload；WhenKdisconnectswitch,theinputpowerisinterruptedE.energydelivery.Thisshowsthattheimportationofpowertoprovideenergyloadisintermittent,fortheloadcanbeprovidedfortheenergy,Switchingpowersupplymustbeasetofstoragedevices,theswitcheswillbeconnectedtoapartoftheenergystoredintheswitchdisconnected.Loadtotherelease.MapfromtheinductanceL,capacitancediodeDandC2componentsofthecircuit,itissuchafunction.InductorLforenergystorageinswitchdisconnected,storedintheinductorLofenergyreleasethroughdiodesDtoload,sothatloadiscontinuousandstableenergy,diodeDenablecontinuousloadcurrent,knownasthecontinuedflowdiode.ABintheaveragevoltageEABcanbegivenby:EAB=TON/T*EwhereTONconnectedtotheswitcheachtime,T-offswitchforthecycle(thatis,accesstimeTONswitchandturn-offtimeandTOFFs).-WecanseefromthechangeswitchconnectedtotheworkcycletimeandtheratioofthevoltagebetweentheABaveragechangealso,therefore,WiththeloadandinputsupplyvoltagechangesandautomaticallyadjustTONTratio,itwillcausetheoutputvoltageV0unchanged.ChangetheaccesstimeandcycleTONpercentagechangeisthepulsedutycycle.Thismethod,knownastimeratiocontrol(TimeRatioControl,fortheinitialsTRC).TRCundercontrolprinciple,therearethreeways:1.Pulsewidthmodulation(PulseWidthModulation,acronymforPWM)switchingconstantcyclebychangingthepulsewidthtochangethedutycycleapproaches.2,pulsefrequencymodulation(PulseFrequencyModulation,acronymforthePFM)conductionpulsewidthconstantbychangingtheswitchingfrequencytochangethedutycycleapproaches.3,mixedconductionmodulationandpulsewidthswitchingfrequencynotfixedare,theychangethewayItismorethantwohybridmodels.SMPSdevelopmentsandtrendsintheUnitedStatesin1955Roje(GH.Roger)inventionoftheself-excitedoscillationpushredeemtransistorsingletransformerDCconverters,high-frequencyconversionisthebeginningofcontrolcircuit,1957UnitedStatesinvestigationtournament(JenSen)sincetheinventionofthepush-pulldoubleFlybacktransformers,1964Americanscientistsproposestoabolishthefrequencytransformerseriesswitchingpowersupplyscenario,Thispowertotherightsizeandweightofthedeclinewasafundamentalway.Tothe1969high-powersilicontransistorbecausethepressureincreasediodereverserecoverytimeshortened,andothercomponentsimprove,andfinallyturnedintoa25kHzswitchingpowersupply.Currently,switchingpowersupplytosmall,Lightvolumeandthecharacteristicsofhighefficiencyhasbeenwidelyusedinelectroniccomputer-drivenvarietyofterminalequipment,Communicationsequipmentalmostallelectronicequipment,theelectronicinformationindustryindispensabletotherapiddevelopmentofapowermode.Currentlythemarketforsaleintheswitchingpowersupplyusingbipolartransistorsmadeof100kHz.usemadeof500kHzMOSpower,thoughpractical,butitsfrequencytobefurtherenhanced.Toimprovetheswitchingfrequency,itisnecessarytoreducetheswitchingloss,andtoreducetheswitchingloss,youneedtohavehigh-speedswitchingdevices.However,theswitchingspeed,willbeaffectedbythecircuitinductanceandcapacitancediodeorstoredchargearisingfromtheimpactofthesurgeornoise.Thiswillnotonlyaffectthesurroundingelectronicequipment,butalsogreatlyreducethereliabilityofthepowersupplyitself.Amongthem,withtheswitchtopreventKai-closedbythevoltagesurge,itisR-CorL-CCompositebumpers,andthestoragechargebythediodecurrentsurgecausedbytheusemadeofamorphouscoressuchasmagneticbumper.However,thehighfrequencyof1MHzandabove,usingresonantcircuit,Switchtoenablethevoltageorcurrentthroughtheswitchwasasine,whichcouldreducetheswitchingloss,Thiscanalsocontrolthesurgeoccurred.Switchessuchasresonantmodeswitching.CurrentlysuchSMPSofveryactive,becausethismeansnosignificantincreaseswitchingspeedcantheoreticallyputswitchinglossfalltozero.andthenoiseissmall,isexpectedtobecomehigh-frequencyswitchingpowersupplyofoneofthemainways.Atpresent,manycountriesintheworldareworkingonseveraltrillionHzconverterpracticalresearch.高頻開關(guān)電源電路原理高頻開關(guān)電源由以下幾個(gè)部分組成：一、主電路從交流電網(wǎng)輸入、直流輸出的全過程，包括：1、輸入濾波器：其作用是將電網(wǎng)存在的雜波過濾，同時(shí)也阻礙本機(jī)產(chǎn)生的雜波反饋到公共電網(wǎng)。2、整流與濾波：將電網(wǎng)交流電源直接整流為較平滑的直流電，以供下一級變換。3、逆變：將整流后的直流電變?yōu)楦哳l交流電，這是高頻開關(guān)電源的核心部分，頻率越高，體積、重量與輸出功率之比越小。4、輸出整流與濾波：根據(jù)負(fù)載需要，提供穩(wěn)定可靠的直流電源。二、控制電路一方面從輸出端取樣，經(jīng)與設(shè)定標(biāo)準(zhǔn)進(jìn)行比較，然后去控制逆變器，改變其頻率或脈寬，達(dá)到輸出穩(wěn)定，另一方面，根據(jù)測試電路提供的資料，經(jīng)保護(hù)電路鑒別，提供控制電路對整機(jī)進(jìn)行各種保護(hù)措施。三、除了提供保護(hù)電路中正在運(yùn)行中各種參數(shù)外，還提供各種顯示儀表資料。四、輔助電源提供所有單一電路的不同要求電源。開關(guān)控制穩(wěn)壓原理開關(guān)K以一定的時(shí)間間隔重復(fù)地接通和斷開，在開關(guān)K接通時(shí)，輸入電源E通過開關(guān)K和濾波電路提供給負(fù)載RL，在整個(gè)開關(guān)接通期間，電源E向負(fù)載提供能量；當(dāng)開關(guān)K斷開時(shí)，輸入電源E便中斷了能量的提供?？梢?，輸入電源向負(fù)載提供能量是斷續(xù)的，為使負(fù)載能得到連續(xù)的能量提供，開關(guān)穩(wěn)壓電源必須要有一套儲能裝置，在開關(guān)接通時(shí)將一部份能量儲存起來，在開關(guān)斷開時(shí)，向負(fù)載釋放。圖中，由電感L、電容C2和二極管D組成的電路，就具有這種功能。電感L用以儲存能量，在開關(guān)斷開時(shí)，儲存在電感L中的能量通過二極管D釋放給負(fù)載，使負(fù)載得到連續(xù)而穩(wěn)定的能量，因二極管D使負(fù)載電流連續(xù)不斷，所以稱為續(xù)流二極管。在AB間的電壓平均值EAB可用下式表示：EAB=TON/T*E式中TON為開關(guān)每次接通的時(shí)間，T為開關(guān)通斷的工作周期（即開關(guān)接通時(shí)間TON和關(guān)斷時(shí)間TOFF之和）。由式可知，改變開關(guān)接通時(shí)間和工作周期的比例，AB間電壓的平均值也隨之改變，因此，隨著負(fù)載及輸入電源電壓的變化自動(dòng)調(diào)整TON和T的比例便能使輸出電壓V0維持不變。改變接通時(shí)間TON和工作周期比例亦即改變脈沖的占空比，這種方法稱為“時(shí)間比率控制”（TimeRatioControl,縮寫為TRC）。按TRC控制原理，有三種方式：一、脈沖寬度調(diào)制（PulseWidthModulation,縮寫為PWM）開關(guān)周期恒定，通過改變脈沖寬度來改變占空比的方式。二、脈沖頻率調(diào)制（PulseFrequencyModulation,縮寫為PFM）導(dǎo)通脈沖寬度恒定，通過改變開關(guān)工作頻率來改變占空比的方式。三、混合調(diào)制導(dǎo)通脈沖寬度和開關(guān)工作頻率均不固定，彼此都能改變的方式，它是以上二種方式的混合。開關(guān)電源的發(fā)展和趨勢1955年美國羅耶（GH.Roger)發(fā)明