開關(guān)電源拓?fù)浣Y(jié)構(gòu)詳述課件

PowerSupplyTopologies

電源拓?fù)浣Y(jié)構(gòu)AMOI家用系統(tǒng)設(shè)計部

PowerSupplyTopologies

電源拓?fù)浣Y(jié)構(gòu)AMOI家用系統(tǒng)設(shè)計部

TheMostPopularTopologies

最常見的拓?fù)浣Y(jié)構(gòu)Buck

降壓Boost

升壓Buck-Boost

降壓-升壓Flyback

反激Forward

正激Two-TransistorForward

雙晶體管正激Push-Pull

推挽HalfBridge

半橋FullBridge

全橋SEPICC’ukDetailsoftheCircuitOperatio

電路工作的細(xì)節(jié)Buck

降壓Buckstheinputdowntoalowervoltage.

把輸入降至一個較低的電壓。Perhapsthesimplestofall.

可能是最簡單的電路。Theinductor/capacitorfilteraveragestherectangularwavefromtheswitch.

電感/電容濾波器濾平開關(guān)后的方波。Outputisalwayslessthanorequaltotheinput.

輸出總是小于或等于輸入。Inputcurrentisdiscontinuous(chopped).

輸入電流不連續(xù)(斬波)。Outputcurrentissmooth.

輸出電流平滑。負(fù)載Boost

升壓Booststheinputtoahighervoltage.

把輸入升至一個較高的電壓。Likethebuck,butinductor,switchanddiodearerearranged.

與降壓一樣，但重新安排了電感、開關(guān)和二極管。Outputisalwaysgreaterthanorequaltotheinput.

輸出總是比大于或等于輸入。(neglectingtheforwardvoltagedropofthediode).

(忽略二極管的正向壓降)。Inputcurrentissmooth.

輸入電流平滑。Outputcurrentisdiscontinuous(chopped).

輸出電流不連續(xù)(斬波)。負(fù)載Buck-Boost

降壓-升壓Anotherarrangementoftheinductor,switchanddiode.

電感、開關(guān)和二極管的另一種安排方法。Combinesnegativecharacteristicsofboththebuckandtheboost.

結(jié)合了降壓和升壓電路的缺點(diǎn)。Inputcurrentisdiscontinuous(chopped).

輸入電流不連續(xù)(斬波)。Outputcurrentisalsodiscontinuous(chopped).

輸出電流也不連續(xù)(斬波)。Outputisalwaysinvertedfromtheinput(notecapacitorpolarity),butcanbeoflessorgreatermagnitude.

輸出總是與輸入反向(注意電容的極性)，但是幅度可以小于或大于輸入。The“flyback”converterisactuallyanisolated(transformercoupled)versionofthebuck-boost.

“反激”變換器實(shí)際是降壓-升壓電路隔離（變壓器耦合）形式。負(fù)載Forward

正激Thetransformer-coupledversionofthebuck.

降壓電路的變壓器耦合形式。Discontinuousinputcurrent;smoothoutputcurrent.

不連續(xù)的輸入電流，平滑的輸出電流。Becauseofthetransformer,theoutputcanbelessorgreaterthantheinputandofeitherpolarity.

因?yàn)椴捎米儔浩鳎敵隹梢源笥诨蛐∮谳斎?，可以是任何極性。Multipleoutputsarepossiblebeaddingsecondarywindingsandcircuits.

增加次級繞組和電路可以獲得多個輸出。Thetransformercoremustberesetduringeachswitchingcycle.Apopularwaytodothisistoaddanotherwindingwiththesamenumberofturnsastheprimary.

在每個開關(guān)周期中必須對變壓器磁芯去磁。常用的做法是增加一個與初級繞組匝數(shù)相同的繞組。Energystoredintheprimaryinductanceduringthe“on”timeoftheswitchisdischargedthroughtheextrawindinganddiodeduringthe“off”time.

在開關(guān)接通階段存儲在初級電感中的能量，在開關(guān)斷開階段通過另外的繞組和二極管釋放。負(fù)載復(fù)位Two-TransistorForward

雙晶體管正激Thetwoswitchesoperatesimultaneously.

兩個開關(guān)同時工作。Whentheyturnoff,theenergystoredinthetransformerreversesthepolarityoftheprimary,causingthediodestoconduct.

開關(guān)斷開時，存儲在變壓器中的能量使初級的極性反向，使二極管導(dǎo)通。Majoradvantages:

主要優(yōu)點(diǎn)：Thevoltageoneachswitchneverexceedstheinputvoltage.

每個開關(guān)上的電壓永遠(yuǎn)不會超過輸入電壓。Noresetwindingisneeded.

無需對繞組磁道復(fù)位。負(fù)載Push-Pull

推挽Theswitches(FETs)aredrivenoutofphaseandpulse-widthmodulated(PWM)toregulatetheoutputvoltage.

開關(guān)（FET）的驅(qū)動不同相，進(jìn)行脈沖寬度調(diào)制（PWM）以調(diào)節(jié)輸出電壓。Goodtransformercoreutilization---poweristransferredonbothhalf-cycles.

良好的變壓器磁芯利用率---在兩個半周期中都傳輸功率。Full-wavetopology,sooutputripplefrequencyistwicethetransformerfrequency.

全波拓?fù)浣Y(jié)構(gòu),所以輸出紋波頻率是變壓器頻率的兩倍。VoltagestressontheFETsistwicetheinputvoltage.

施加在FET上的電壓是輸入電壓的兩倍。負(fù)載Mostpopulartopologyforhigh-powerconverters.

較高功率變換器最為常用的拓?fù)浣Y(jié)構(gòu)。Theswitches(FETs)aredrivenindiagonalpairsandpulse-widthmodulated(PWM)toregulatetheoutputvoltage.

開關(guān)（FET）以對角對的形式驅(qū)動，進(jìn)行脈沖寬度調(diào)制（PWM）以調(diào)節(jié)輸出電壓。Goodtransformercoreutilization---poweristransferredonbothhalf-cycles.

良好的變壓器磁芯利用率---在兩個半周期中都傳輸功率。Full-wavetopology;outputripplefrequencyistwicethetransformerfrequency.

全波拓?fù)浣Y(jié)構(gòu)，所以輸出紋波頻率是變壓器頻率的兩倍。VoltagestressontheFETsisequaltotheinputvoltage.

施加在FETs上的電壓與輸入電壓相等。Foragivenpower,primarycurrentishalfthatofthehalf-bridge.

在給定的功率下，初級電流是半橋的一半。負(fù)載Full-Bridge

全橋SEPIC

(Single-EndedPrimaryInductorConverter)

（單端初級電感變換器）Outputvoltagecanbeeitherlessthanorgreaterthantheinput.

輸出電壓可以大于或小于輸入電壓。Liketheboost,theinputcurrentissmoothandoutputcurrentisnot.

與升壓電路一樣，輸入電流平滑，但是輸出電流不連續(xù)。Energyistransferredfrominputtooutputthroughacapacitor.

能量通過電容從輸入傳輸至輸出。Requirestwoinductors.

需要兩個電感。負(fù)載C’uk

(BySlobodanC’uk)

(SlobodanC’uk的專利)Outputisinverted.

輸出反相。Magnitudeofoutputvoltagecanbelessorgreaterthantheinput.

輸出電壓的幅度可以大于或小于輸入。Inputcurrentandoutputcurrentarebothsmooth.

輸入電流和輸出電流都是平滑的。Energyistransferredfrominputtooutputthroughacapacitor.

能量通過電容從輸入傳輸至輸出。Requirestwoinductors.

需要兩個電感。Inductorscanbecoupledtoachievezero-rippleinductorcurrent.

電感可以耦合獲得零紋波電感電流。負(fù)載Inductorcurrentiscontinuous.

電感電流連續(xù)。Voutistheaverageofthevoltageatitsinput(V1).

Vout是其輸入電壓(V1)的均值。Outputvoltageistheinputvoltagetimesthedutyratio(D)oftheswitch.

輸出電壓為輸入電壓乘以開關(guān)的負(fù)荷比(D)。Whenswitchinon,inductorcurrentflowsfromthebattery.

接通時，電感電流從電池流出。Whenswitchisoff,itflowsthroughthediode.

開關(guān)斷開時電流流過二極管。Neglectinglossesintheswitchesandinductor,Disindependentofloadcurrent.

忽略開關(guān)和電感中的損耗,D與負(fù)載電流無關(guān)。Acharacteristicofbuckregulatorsanditsderivatives:

降壓調(diào)整器和其派生電路的特征是：Inputcurrentisdiscontinuous(chopped),andoutputcurrentiscontinuous(smooth).

輸入電流不連續(xù)(斬波),輸出電流連續(xù)(平滑)。BuckRegulator

降壓調(diào)整器

(ContinuousConduction)

(連續(xù)導(dǎo)電)負(fù)載時間Inductorcurrentisstillcontinuous,butjust“touches”zeroastheswitchturnsonagain.

電感電流仍然是連續(xù)的，只是當(dāng)開關(guān)再次接通時“達(dá)到”零。Thisiscalled“criticalconduction.”

這被稱為“臨界導(dǎo)電”。OutputvoltageisstillequaltotheinputvoltagetimesD.

輸出電壓仍等于輸入電壓乘以D。BuckRegulator

降壓調(diào)整器

(CriticalConduction)

(臨界導(dǎo)電)負(fù)載時間BuckRegulator

降壓調(diào)整器

(DiscontinuousConduction)

（不連續(xù)導(dǎo)電）Inthiscase,thecurrentintheinductoriszeroduringpartofeachperiod.

在這種情況下，電感中的電流在每個周期的一段時間中為零。Outputvoltageisstill(asalways)theaverageofv1.

輸出電壓仍然(始終)是v1的平均值。OutputvoltageisNOTtheinputvoltagetimesthedutyratio(D)oftheswitch.

輸出電壓不是輸入電壓乘以開關(guān)的負(fù)荷比(D)。Whiletheloadcurrentisbelowthecriticalvalue,Dvarieswithloadcurrent(whileVoutremainsconstant).

當(dāng)負(fù)載電流低于臨界值時，D隨著負(fù)載電流而變化(而Vout保持不變)。負(fù)載時間TransformerOperation

變壓器工作

IncludingEffectofPrimaryInductance

包括初級電感的作用Transformerisshownasanidealtransformer,withitsprimary(magnetizing)inductanceasaninductorinparallel