3.1.2单相半波可控整流电路 Single phase half wave controllable rectifier circuit 中英版

Powerelectronicstechnology电力电子技术3.1.2Single-phasehalf-wavecontrollablerectifiercircuit3.1.2单相半波可控整流电路Item3Rectifiercircuit项目三整流电路TeachingResourcesDatabaseof

NationalVocationalEducationPowerSupplyTechnologyBilingualcourses.图1单相半波可控整流

Figure1Single-phasehalfwavecontrollablerectifier

1.电阻性负载Resistantload(1)电路图

Circuitdiagram带电阻负载的工作情况Workingconditionofresistiveload变压器T起变换电压和电气隔离的作用。TransformerTplaystheroleofswitchingvoltageandelectricalisolation.电阻负载的特点：电压与电流成正比，两者波形相同。Characteristicofresistanceload:voltageisproportionaltocurrent,bothwaveformsarethesame.3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wwwwtTVTR0a)u1u2uVTudidwt1p2ptttu2uguduVTaq0b)c)d)e)00

在单相相控整流电路中，定义晶闸管从承受正向电压起到触发导通之间的电角度α称为控制角(或移相角)，晶闸管在一个周期内导通的电角度称为导通角，用θ表示。

Inasingle-phasephase-controlledrectifiercircuit,thecontrolAngle(orphase-shiftingAngle)isdefinedastheelectricalAngleαbetweenthethyristorbearingtheforwardvoltageandthetriggerconduction.TheconductionAngleofthethyristorinonecycleiscalledtheconductionAngle,whichisdenotedbyθ.图.1单相半波可控整流Figure1Single-phasehalfwavecontrollablerectifier

1.电阻性负载Resistantload(1)电路图

Circuitdiagram带电阻负载的工作情况Workingconditionofresistiveload3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wwwwtTVTR0a)u1u2uVTudidwt1p2ptttu2uguduVTaq0b)c)d)e)00

上式表明，只要改变控制角α(即改变触发时刻)，就可以改变整流输出电压的平均值，达到相控整流的目的。TheaboveequationshowsthattheaverageoutputvoltageoftherectifiercanbechangedaslongasthecontrolAngleαischanged(thatis,thetriggertimeischanged)toachievethepurposeofphasedrectifier.

(2)电阻性负载时参数计算：

Parametercalculationforresistiveload根据波形图2.2.1(b)，可求出整流输出电压平均值为：Accordingtowaveformfigure2.2.1(b),theaverageoutputvoltageofrectifiercanbecalculatedas移相范围：整流输出电压Ud的平均值从最大值变化到零时，控制角α的变化范围为移相范围。Phase-shiftingrange:WhentheaveragevalueoftherectifieroutputvoltageUd

changesfromthemaximumvaluetozero,thecontrolangleαchangeswithinthephase-shiftingrange当α=0时，Ud=0，当α=π时，Ud=0.45U2为最大值。Whenα=0,Ud

=0,andwhenα=π,Ud

=0.45U2isthemaximumvalue

这种通过控制触发脉冲的相位来控制直流输出电压大小的方式称为相位控制方式，简称相控方式。Bycontrollingthephaseofthetriggerpulsetocontrolthesizeofthedirectcurrentoutputvoltageiscalledphasecontrolmode.单相半波相控整流电路带电阻性负载时移相范围为π。Thesingle-phasehalf-wavephase-controlledrectifiercircuitwitharesistiveloadhasaphaseshiftrangeofπ.图1单相半波可控整流波形图Figure.1Waveformdiagramofsingle-phasehalf-wavecontrollablerectification

3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wwwwtTVTR0a)u1u2uVTudidwt1p2ptttu2uguduVTaq0b)c)d)e)00

(2)电阻性负载时参数计算（续）：Parametercalculationforresistiveload(continued)图1单相半波可控整流波形图Figure.1Waveformdiagramofsingle-phasehalf-wavecontrollablerectification

根据有效值的定义，整流输出电压的有效值为Accordingtothedefinitionofeffectivevalue,theeffectivevalueoftherectifieroutputvoltageis

那么，整流输出电流的平均值Id和有效值I分别为Then,theaveragevalueId

andeffectivevalueIoftherectifieroutputcurrentarerespectively电流的波形系数Kf为ThewaveformcoefficientofthecurrentKfis

上式(2.2.7)表明，控制角α越大，波形系数Kf越大。Equation(2.2.7)aboveindicatesthatthelargerthecontrolAngleαis,thelargerthewaveformcoefficientKf

is.

3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wwwwtTVTR0a)u1u2uVTudidwt1p2ptttu2uguduVTaq0b)c)d)e)00

(2)电阻性负载时参数计算（续）：Parametercalculationforresistiveload(continued)

如果忽略晶闸管T的损耗，则变压器二次侧输出的有功功率为IfthelossofthyristorTisignored,theactivepoweroutputofthesecondarysideofthetransformeris电源输入的视在功率为Apparentpowerinputis从上式可知，功率因数是控制角α的函数，且越α大，相控整流输出电压越低，功率因数PF越小。Fromtheaboveequation,itcanbeseenthatthepowerfactorisafunctionofthecontrolAngleα,andthelargertheαis,thelowertheoutputvoltageofthephasedrectifieris,andthesmallerthepowerfactorPFis.当α=0时，PF=0.707为最大值。这是因为电路的输出电流中不仅存在谐波，而且基波电流与基波电压(即电源输入正弦电压)也不同相，即是使电阻性负载，PF也不会等于1。Whenα=0,PF=0.707isthemaximumvalue.Thisisbecausetherearenotonlyharmonicsintheoutputcurrentofthecircuit,butalsothefundamentalcurrentandfundamentalvoltage(thatis,thesinusoidalvoltageofthesupplyinput)areindifferentphases,soevenforresistiveload,pFwillnotequal1.电路的功率因数Powerfactorofthecircuit3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wwwwtTVTR0a)u1u2uVTudidwt1p2ptttu2uguduVTaq0b)c)d)e)00图1单相半波可控整流波形图Figure.1Waveformdiagramofsingle-phasehalf-wavecontrollablerectification

2.电感性负载Inductiveload（等效为电感L和电阻R串联）EquivalenttoinductanceLandresistorRinseries图2感性负载单相半波可控整流电路及其波形Figure2Single-phasehalf-wavecontrollablerectifiercircuitwithinductiveloadanditswaveformdiagram工作原理Workingprinciple3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wttwwtwtwu20wt1p2ptug0ud0id0uVT0qab)c)d)e)f)++TVTRa)u1u2uVTudid阻感负载的特点：电感对电流变化有抗拒作用，使得流过电感的电流不发生突变。Thecharacteristicsofresistanceload:theinductorcanresistthechangeofcurrent,sothatthecurrentthroughtheinductordoesnotchangeabruptly.

2.电感性负载(续)Inductiveload(continued)感性负载上的输出电压平均值Ud为TheaverageoutputvoltageoninductiveloadisUd故So

上式表明,感性负载上的电压平均值等于负载电阻上的电压平均值。Theaboveequationindicatesthattheaveragevoltageacrosstheinductiveloadisequaltotheaveragevoltageacrosstheloadresistor.3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路

由于负载中存在电感，使负载电压波形出现负值部分，晶闸管的流通角θ变大，且负载中L越大，θ越大，输出电压波形图上负压的面积越大，从而使输出电压平均值减小。Duetothepresenceofinductanceintheload,theloadvoltagewaveformappearsnegativepart,thecurrentAngleθofthethyristorincreases,andthelargertheloadL,thelargerθ,thelargertheareaofnegativepressureintheoutputvoltagewaveform,sothattheaverageoutputvoltagedecreases.在大电感负载ωL>>R的情况下，负载电压波形图中正负面积相近，即不论α为何值，，都有。InlargeinductiveloadwhenωL>>R;InthecaseofR,thepositiveandnegativeareasintheloadvoltagewaveformaresimilar,thatis,regardlessofthevalueofα,alwayshas

2.电感性负载（大电感ωL＞＞R

）Inductiveload(largeinductanceωL＞＞R

)图2.2.4ωL>>R时不同α时的电流波形Figure2.2.4whenωL>>Rthecurrentwaveformatdifferentα3.1.2Single-phasehalf-wavecontrollablerectifiercircuit单相半波可控整流电路wttwwtwtwu20wt1p2ptug0ud0id0uVT0qab)c)d)e)f)++优点：Advantages

线路简单，调整方便；

Thecircuitissimpleandeasytoadjust缺点：Disadvantage

（1）输出电压脉动大，负载电流脉动大（电阻性负载时）。Theoutputvoltagepulsationislarge,theloadcurrentpulsationislarge(resistiveload).

（2）整流变压器次级绕组中存在直流电流分量，使铁芯磁化，变压器容量不能充分利用。若不用变压器，则交流回路有直流电流，使电网波形畸变引起额外损耗。

ThereisaDCcurrentcomponentinthesecondarywindingoftherectifiertransformer,whichmakestheironcoremagnetized,andthetran