6.1 交流调压电路 AC voltage regulating circuit中英版

Item6Alternatingcurrentconversioncircuit项目六交流变换电路6.1Alternatingcurrentvoltageregulatingcircuit6.1交流调压电路TeachingResourcesDatabaseof

NationalVocationalEducationPowerSupplyTechnologyBilingualcourses.Powerelectronicstechnology电力电子技术交流变换电路：把交流电能的参数（幅值、频率、相位）加以转换的电路。ACconversioncircuit:Acircuitthatconvertstheparameters(amplitude,frequency,phase)ofACenergy.交流电力控制电路ACpowercontrolcircuit

交一交变频电路（直接变频电路）AC-ACfrequencyconversioncircuit(directfrequencyconversioncircuit)维持频率不变改变输出电压的幅值。Changetheamplitudeoftheoutputvoltagewhilekeepingthefrequencyconstant.

将电网频率的交流电直接变换成较低频率的交流电直接变频的同时也可实现电压变换。TheACofthepowernetworkfrequencyisdirectlyconvertedtotheACoflowerfrequency,andthevoltageconversioncanberealizedatthesametime.分类Classification6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路3.交流调压电路应用：ACvoltageregulatingcircuitapplication

电炉的温度控制

Temperaturecontrolofelectricfurnace灯光调节（如舞台灯光控制）

Lightingcontrolsuchasstagelightingcontrol)异步电机软起动

Softstartofinductionmotor异步电机调速Inductionmotorspeedregulation调节整流变压器一次侧电压Adjustprimarysidevoltageofrectifiertransformer2.交流调压的实现方法：通过控制晶闸管在每一个电源周期内的导通角的大小（相位控制）来调节输出电压的大小。ThemethodofACvoltageregulation:bycontrollingthesizeofthethyristorconductionAngleineachpowercycle(phasecontrol)toadjustthesizeoftheoutputvoltage.1.交流调压电路:是用来变换交流电压幅值（或有效值）的电路。ACvoltageregulatingcircuit:itisusedtotransformtheACvoltageamplitude(oreffectivevalue)circuit.6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路单相交流调压器主电路特点：

SinglephaseACvoltageregulatormaincircuitcharacteristics:T1

、T2

构成无触点交流开关。T1andT2constituteacontactlessACswitch.1）电源正半周：T1触发导通，电源的正半周施加到负载上；Positivehalfcycleofpowersupply:T1triggertoturnon,thepositivehalfcycleofpowersupplyisappliedtotheload;2）电源负半周：T2触发导通，电源负半周便加到负载上；Powersupplynegativehalfcycle:T2triggeron,powersupplynegativehalfcyclewillbeaddedtotheload;3）电源电压过零：T1

、T2交替触发导通，电源电压全部加到负载；Powersupplyvoltagezerocrossing:T1,T2alternatelytriggeron,powersupplyvoltageisalladdedtotheload;4）关断T1

、T2

：电源电压不能加到负载上。TurnoffT1andT2:thepowersupplyvoltagecannotbeaddedtotheload.图1单向交流调压器电路Figure1one-wayACvoltageregulatorcircuit单向交流电压电路的工作情况与它的负载性质有关Theoperationofone-wayACvoltagecircuitisrelatedtothenatureofitsload

6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路1）电源电压正半周：晶闸管T1承受正向电压，当ωt=α时，触发T1使其导通，负载上得到缺α角的正弦半波电压；Positivehalfcycleofpowersupplyvoltage:ThyristorT1issubjectedtopositivevoltage.Whenωt=α,itwilltriggerT1toturnon,andsinehalfwavevoltagewithoutαanglewillbeobtainedontheload;2）电源电压过零：T1管电流下降为零而关断；Thepowersupplyvoltagecrosseszero:T1tubecurrentdropstozeroandshutsoff;3）电源电压负半周：晶闸管T2承受正向电压，当ωt=π+α时，触发T2使其导通，则负载上又得到了缺α角的正弦负半波电压。持续这样控制，在负载电阻上便得到每半波缺α角的正弦电压；Negativehalfcycleofpowersupplyvoltage:ThyristorT2issubjectedtopositivevoltage.Whenωt=π+α,T2istriggeredtoturnon,andsinenegativehalfwavevoltagewithoutαAngleisobtainedontheload.Continuedinthisway,asinusoidalvoltageisobtainedacrosstheloadresistoratanAngleminusalphaforeachhalfwave;图2电阻性负载时单向交流电压电路及输出电压波形Figure2one-wayACvoltagecircuitandoutputvoltagewaveformunderresistiveload改变α角的大小，便改变了输出电压有效值的大小。TheeffectivevalueoftheoutputvoltageischangedbychangingthesizeofthealphaAngle.1.电阻性负载Resistantload6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路电阻性负载数量关系：Quantityrelationofresistiveload

负载电压的有效值Theeffectivevalueoftheloadvoltage

负载电流的有效值

Theeffectivevalueoftheloadcurrent

调压器的效率

Voltageregulatorefficiency总结：随着α角的增大，U0逐渐减小。当α=π时，U0=0。因此，单相交流调压器对于电阻性负载，其电压可调范围为0～U，控制角α的移相范围为0～π。Conclusion:U0

decreaseswiththeincreaseofα

angle.Whenα=π,U0=0.Therefore,forresistiveload,thevoltageadjustablerangeofsingle-phaseACregulatoris0~U,andthephaseshiftrangeofcontrolangleαis0~π.图2电阻性负载时单向交流电压电路及输出电压波形Figure2one-wayACvoltagecircuitandoutputvoltagewaveformunderresistiveload6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路2.感性负载（R-L负载）Inductiveload(R-Lload)图3带阻感负载单向交流调压电路及输出波形Figure3One-wayACvoltageregulatorcircuitwithresistiveloadanditsoutputwaveform

单相交流调压器带阻感负载时，工作情况同可控整流电路带电感负载相似；Single-phaseACvoltageregulatorwithresistiveload,theworkingsituationissimilartothecontrollablerectifiercircuitwithinductiveload;

当电源电压反向过零时，负载电感产生感应电动势阻止电流的变化，故电流不能立即为零；Whenthepowersupplyvoltagereversezero,theloadinductorproducesaninducedelectromotiveforcetopreventthechangeofcurrent,sothecurrentcannotbeimmediatelyzero;晶闸管的导通角θ的大小与控制角a

、负载阻抗角φ都有关。Theconductionangleθofthethyristorisrelatedtothecontrolanglea

andtheloadimpedanceangleφ.6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路

阻感负载的工作情况分析：Workingconditionanalysisofresistiveload

晶闸管T1导通时，负载电流IO为：WhenthyristorT1ison,theloadcurrentIois式中intheformula

（θ为晶闸管的导通角θistheconductionAngleofthethyristor）T2导通时，上述关系完全相同，只是iO相差1800WhenT2ison,therelationshipisexactlythesame,exceptthatthedifferenceiniO

is1800图4单相交流调压器以φ为参变量时θ与a的关系曲线Figure4Therelationcurvebetweenθandawhenφistakenastheparameterofsingle-phaseACregulator利用边界条件Usingboundaryconditions：,i0=0可求得θ：

θcanbeobtained6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路1.α>ф，导通角θ≺1800，正负半波电流断续。α愈大，θ愈小，波形断续愈严重。Theα>ф,conductionangleθ≺1800,positiveandnegativehalfwavecurrentisdiscontinuous.Thelargertheαis,thesmallertheθis,themoreseriousthewaveformdiscontinuityis.

负载电压的有效值UO、晶闸管电流平均值IdT、晶闸管电流有效值IT以及负载电流有效值IO分别为：TheeffectivevalueofloadvoltageUo,themeanvalueofthyristorcurrentIdT,theeffectivevalueofthyristorcurrentIT

andtheeffectivevalueofloadcurrentIO

arerespectively调压电路的工作情况Operatingconditionofvoltageregulatingcircuit（α>ф

、α=ф、α<ф

）6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路2.α=ф可得：Wecangetθ=1800

此时，晶闸管轮流导通，相当于晶闸管被短接。负载电流处于连续状态，为完全的正弦波。Atthispoint,thethyristorisswitchedoninturn,itisequivalentthatthethyristorbeingshorted.Theloadcurrentisinacontinuousstateandisacompletesinewave

由Since6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路图5窄脉冲触发时的工作波形Figure5Workingwaveformofnarrowpulsetriggered

如果采用窄脉冲触发，会出现先触发的一只晶闸管导通，而另一只管子在电流下降为零时，因其门极脉冲已经消失不能导通的失控现象。回路中将出现很大的直流电流分量，无法维持电路的正常工作。Ifanarrowpulseisused,arunawayphenomenonoccurswhenoneofthethyristorsisactivatedfirst,andtheothertubeisunabletoconductwhenthecurrentdropstozerobecauseitsgatepulsehasdisappeared.TherewillbealargeDCcurrentcomponentintheloop,whichwillnotbeabletomaintainthenormaloperationofthecircuit.解决办法：采用宽脉冲或脉冲列触发，使第二个晶闸管的导通角θ<π。即可使两个晶闸管的导通角θ=1800达到平衡。解决失控现象。Solution:Useawidepulseorpulsetraintotriggerthesecondthyristor'sconductionangleθ<π.Theconductionangleθ=1800ofthetwothyristorscanbebalanced.Solveout-of-controlphenomena.3.α<фθ＞18006.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路单相交流调压电路总结：Summaryofsingle-phaseACvoltageregulatorcircuit当时，并采用宽脉冲触发，负载电压、电流总是完整的正弦波，改变控制角a,负载电压、电流的有效值不变，即电路失去交流调压的作用。When,andusingawidepulsetrigger,theloadvoltageandcurrentarealwayscompletesinewave,changethecontrolanglea,theloadvoltageandcurrentoftheeffectivevalueofthesame,thatis,thecircuitlosestheroleofACvoltageregulation.在电感负载时，要实现交流调压的目的，则最小控制角（负载的功率因数角）。所以

的移相范围为φ～1800

Theminimumcontrolangle(thepowerfactorangleoftheload)isrequiredforthepurposeofACvoltageregulationwhentheinductorisloaded.Sothephaseshiftrangeofisφ～1800

6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路图5窄脉冲触发时的工作波形Figure5Workingwaveformofnarrowpulsetriggered

1.三相四线制调压电路特点：Characteristicsofthree-phasefour-wirevoltageregulatingcircuit

图6三相四线制调压电路Figure6Three-phasefour-wirevoltageregulationcircuit

1）相当于三个独立的单相交流调压电路组合而成的；Equivalenttothecombinationofthreeindependentsingle-phaseACvoltageregulatingcircuits

2）存在中性线，但是3次谐波在中线中的电流大，故中线的导线截面要求与相线一致；Thereisaneutralline,butthecurrentofthethirdharmonicinthecenterlineislarge,sothewirecrosssectionofthecenterlineisrequiredtobeconsistentwiththephaseline;

3）晶闸管的门极触发脉冲信号，同相间两管的触发脉冲要互差180°。

Thegatepoleofthethyristortriggersthepulsesignal.Thetriggerpulseofthetwotubeswiththesamephaseshouldbe180°differentfromeachother.

4）各晶闸管导通顺序为T1～T6，依次滞后间隔60°；TheconductionsequenceofeachthyristorisT1～T6,andthedelayintervalis60°successively;

5）因存在中线，可采用窄脉冲触发；Becausethereisamidline,narrowpulsecanbeusedtotrigger;

6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路

6）该电路工作时，零线上谐波电流较大，含有三次谐波，控制角a=90°时，零线电流甚至和各相电流的有效值接近。若变压器采用三柱式结构，则三次谐波磁通不能在铁心中形成通路，产生较大的漏磁通，引起发热和噪音。Whenthecircuitworks,theharmoniccurrentonthezerolineislarge,includingthethirdharmonic.WhenthecontrolAngleA=90°,thezerolinecurrentisevenclosetotheeffectivevalueofeachphasecurrent.Ifthetransformeradoptsathree-columnstructure,thethirdharmonicfluxcannotformapathinthecore,resultinginlargefluxleakage,causingheatandnoise.

7）该电路中晶闸管上承受的峰值电压为

(

为线电压)。Thepeakvoltageonthethyristorinthecircuitis(isthelinevoltage)6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路图6三相四线制调压电路Figure6Three-phasefour-wirevoltageregulationcircuit1.三相四线制调压电路特点：Characteristicsofthree-phasefour-wirevoltageregulatingcircuit

2.三相三线制交流调压电路的特点Thecharacteristicsofthree-phasethree-wireACvoltageregulatingcircuit

图7三相三线制交流调压电路Figure7

Three-phasethree-wireACvoltageregulatingcircuit

1）每相电路必须通过另一相形成回路；

Eachphasecircuitmustpassthroughanotherphasetoformaloop;

2）负载接线灵活，且不用中性线；Theloadwiringisflexible,andnoneutralline

3）晶闸管的触发电路必须是双脉冲，或者是宽度大于600的单脉冲Thetriggercircuitofthethyristormustbeadoublepulse,orasinglepulsewidthgreaterthan600；

4）触发脉冲顺序和三相全控桥一样，为T1～T6，依次间隔600；

Thesequenceoftriggeringpulsesisthesameasthatofthree-phasefullycontrolledbridge,T1～T6,withanintervalof600;

5）电压过零处定为控制角的起点，a角移相范围是0°～150°；Thevoltagezerocrossingissetasthestartingpointofthecontrolangle,andthephaseshiftrangeofanglea

is0°~150°;

6)输出谐波含量低,无3次谐波；

Lowoutputharmoniccontent,nothirdharmonicwave;

4626.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路

图8a=0°时负载相电压波形Figure8Loadphasevoltagewaveformwhena=0°

(1)0°≤a<60°时，三个晶闸管导通与两个晶闸管导通交替，每管导通180°－a

。但a=0°时一直是三管导通，图8所示a=0°时的负载电压波形。When0°≤a<60°,threethyristorsconductalternatelywithtwothyristors,eachconducting180°-a.However,whena=0°,thethreepipesarealwayson.Figure8showstheloadvoltagewaveformwhena=0°.3.三相三线制交流调压电路改变α，电路中晶闸管的导电模式Thethree-phasethree-wireACvoltageregulatingcircuitchangesα,theconductionmodeofthethyristorinthecircuit6.1Alternatingcurrentvoltageregulatingcircuit

交流调压电路Rangeofthyristorconduction

图9