pwm整流器外文翻译.docx
- 文档编号:3116467
- 上传时间:2022-11-17
- 格式:DOCX
- 页数:16
- 大小:294.44KB
pwm整流器外文翻译.docx
《pwm整流器外文翻译.docx》由会员分享,可在线阅读,更多相关《pwm整流器外文翻译.docx(16页珍藏版)》请在冰豆网上搜索。
pwm整流器外文翻译
ACVoltageandCurrentSensorlessControlof
Three-PhasePWMRectifiers
Dong-ChoonLee,Member,IEEE,andDae-SikLim
1THREE-PHASEPWMRECTIFIERS
ASystemModeling
Fig.1showsthepowercircuitofthethree-phasePWMrectifier.Thevoltageequationsaregivenby
(1)
Fig.1.Three-phasePWMrectifierwithoutac-sidesensors.
where,andarethesourcevoltage,thelinecurrent,andtherectifierinputvoltage,respectivelyandaretheinputresistanceandtheinputinductance,respectively.Whenthepeaklinevoltage,angularfrequency,andinitialphaseanglearegiven,assumingabalancedthree-phasesystem,thesourcephasevoltageisexpressedas
(2)
Where
(3)
Atransformationmatrixbasedontheestimatedphaseangle,whichtransformsthree-phasevariablesintoasynchronousd–qreferenceframe,is
(4)
Transforming
(1)intothe–referenceframeusing(4)
(5)
wherepisadifferentialoperatorand.
Expressing(5)inavectornotation
(6)
where,
(7)
Takingatransformationof
(2)byusing(4)
(8)
Where
(9)
Expressing(6)and(8)inadiscretedomain,byapproximatingthederivativetermin(6)byaforwarddifference[9],respectively,
(10)
(11)
WhereTisthesamplingperiod.
Fig.2.Overallcontrolblockdiagram.
BSystemControl
ThePIcontrollersareusedtoregulatethedcoutputvoltageandtheacinputcurrent.Fordecouplingcurrentcontrol,thecross-couplingtermsarecompensatedinafeedforward-typeandthesourcevoltageisalsocompensatedasadisturbance.Fortransientresponseswithoutovershoot,theanti-winduptechniqueisemployed[10].TheoverallcontrolblockdiagrameliminatingthesourcevoltageandlinecurrentsensorsisshowninFig.2.Theestimationalgorithmofsourcevoltagesandlinecurrentsisdescribedinthefollowingsections.
2PREDICTIVECURRENTESTIMATION
Thecurrentsof
and
cannotbecalculatedinstantlysincethecalculationtimeoftheDSPisrequired.Toeliminatethedelayeffect,astateobservercanbeused.Inaddition,thestateobserverprovidesthefilteringeffectsfortheestimatedvariable.
Expressing(5)inastate-spaceform,
(12)
(13)
where,
Andyistheoutput.
Transforming(12)and(13)intoadiscretedomain,respectively,
(14)
(15)
where,
Then,theobserverequationaddinganerrorcorrectiontermtoisgivenby
(16)
WhereKistheobservergainmatrixand“^”meanstheestimatedquantity,and
isthestatevariableestimatedaheadonesamplingperiod.Subtracting(15)from(16),theerrordynamicequationoftheobserverisexpressedas
(17)
where
.Here,itisassumedthatthemodelparametersmatchwellwiththerealones.Fig.3showstheblockdiagramoftheclosed-loopstateobserver.
Thestatevariableerrordependsonlyontheinitialerrorandisindependentoftheinput.For(17)toconvergetothezerostate,therootsofthecharacteristicequationof(17)shouldbelocatedwithintheunitcircle.
Fig.3.Closed-loopstateobserver.
Fig.4.Shortpulseregion.
3EXPERIMENTSANDDISCUSSIONS
A.SystemHardwareConfiguration
Fig.5showsthesystemhardwareconfiguration.Thesourcevoltageisathree-phase,110[V].Theinputresistanceandinductanceare0.06Ωand3.3mH,respectively.Thedclinkcapacitanceis2350μFandtheswitchingfrequencyofthePWMrectifieris3.5kHz.
Fig.5.Systemhardwareconfiguration.
Fig.6.Dclinkcurrentsandcorrespondingphasecurrents(insectorV).
TheTMS320C31DSPchipoperatingat33.3MHzisusedasamainprocessorandtwo12-bA/Dconvertersareused.Oneofthemisdedicatedfordetectingthedclinkcurrentandtheotherisusedformeasuringthedcoutputvoltageandthesourcevoltagesandcurrents,whereacsidequantitiesarejustmeasuredforperformancecomparison.
OneoftwointernaltimersintheDSPisemployedtodecidethePWMcontrolperiodandtheotherisusedtodeterminethedclinkcurrentinterrupt.Consideringtherectifierblankingtimeof3.5s,A/Dconversiontimeof2.6s,andtheothersignaldelaytime,theminimumpulsewidthissetto10s.
A.ExperimentalResults
Fig.6showsmeasureddclinkcurrentsandphasecurrents.IncaseofsectorVofthespacevectordiagram,thedclinkcurrentcorrespondstofortheswitchingstateofandforthatof.Fig.7(a)showstherawdclinkcurrentbeforefiltering.Ithasalotofringingcomponentsduetotheresonanceoftheleakageinductanceandthesnubbercapacitor.Whenthedccurrentissampledattheendpointoftheactivevoltagevectorsasshowninthefigure,themeasuringerrorcanbereduced.
Fig.7.Samplingofdclinkcurrents.
Fig.8.Estimatedsourcevoltageandcurrentatstarting.
Toreducethiserrorfurther,thelowpassfiltershouldbeemployed,ofwhichresultiss
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- pwm 整流器 外文 翻译
![提示](https://static.bdocx.com/images/bang_tan.gif)