电气工程及其自动化专业英语 课件 -Chapter 6：Flexible AC Transmission Systems (FACTS)

目录Introduction6.1StaticVarCompensator(SVC)6.2UniformPowerFlowController(UPFC) 6.3Bridge-TypeFaultCurrentController(FCC)6.4Chapter6：FlexibleacTransmissionSystems(FACTs)thermal['θə:məl]adj.热的，热量的thrust[θrʌst]n.推力；刺compensator['kɔmpənseitə]n.补偿器；自耦变压器flywheel['flaiwi:l]n.飞轮，惯性轮；调速轮margin['mɑ:dʒin]n.界限；差数；幅度oscillation[,ɔsi'leiʃən]n.振荡；振动；摆动bulk[bʌlk]n.（巨大的）体积，容积；容量，(大)量alleviate[ə'li:vieit]vt.减轻，缓和meshed[meʃt]adj.网状的；有网孔的shaft[ʃæft]n.拍杆；轴turbine['tə:bain,-bin]n.涡轮；涡轮机Anovelstaticvar（）basedonPWMtechnologywasintroduced.compensatortransformercurrenttransformerelectricreactorABCD提交单选题1分Thereareafewtechnicaldifficulties,butIbelieveinthenextfivetotenyearswewillbeinstallingcommercialmarine（）farms.hingewindmillengineturbineABCD提交单选题1分detune[di:'tu:n]vt.使去谐；降低（调门）collaborative[kə'læbərətiv]adj.合作的，协作的prototype['prəutətaip]n.原型；标准，模范deionize[di:'aiənaiz]vt.除去离子；消电离ambient['æmbiənt]adj.周围的；环绕的；外界的mitigate['mitiɡeit]vt.使缓和，使减轻modularity[,mɔdju'læriti,-dʒu-]n.模块性intertie['intətai]n.（美）联锁电力网steeply['sti:pli]adv.陡峭地；险峻地perpendicular[,pə:pən'dikjulə]adj.垂直的，正交的；直立的rectify['rektifai]vt.整流Diodesareelectronicdeviceswhich（）alternatingcurrenttodirectcurrent.alterrectifyboostoptimizeABCD提交单选题1分demonstration

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[təu'pɔlədʒi,tɔ-]n.拓扑结构，拓扑temporarily['tempərərili,,tempə'rεə-]adv.临时地，临时ruggedness['rʌgidnis]n.强度，坚固性sinusoidal[,sinə'sɔidl]adj.正弦曲线的fabricate['fæbrikeit]vt.制造；装配Thisistheproposed

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environment.（）.topologytrophictopologturpitudeABCD提交单选题1分（）steady-statemaximumaveragepowertransfertheoremisimportantcontentincircuitteaching.cosinequadratureSinusoidalbowstringABCD提交单选题1分superimposed['sju:pəim'pəuzd]adj.叠加的；上叠的；重迭的delta[‘deltə]n.三角型物Theopendeltawindingofa

Three-phasefive-columnvoltagetransformercanbeusedfor()LowvoltageprotectionmeasuringnegativesequencevoltagemeasuringzerosequencevoltageUndervoltagewarningABCD提交单选题1分目录Introduction6.1StaticVarCompensator(SVC)6.2UniformPowerFlowController(UPFC) 1026.3Bridge-TypeFaultCurrentController(FCC)6.46.1IntroductionTightercontrolofpowerflowandincreaseduseoftransmissioncapacityarekeybenefitsofnewthyristor-basedcontrollers.Apowerlinecanfunctionneareritstopthermalratingifregulatedbyflexibleactransmissionsystemcontrollers.新型晶闸管控制器的主要优点是能更准确地控制潮流和更多地利用传输容量。如果采用灵活的交流传输系统控制器调节，输电线路可在接近最高允许额定温度的情况下运行。6.1IntroductionTheelectricutilities’systemsfortransmittinganddistributingpowerareenteringaperiodofchange.Theiroperationisfine-tunedtoanunprecedenteddegree,bytheapplicationofpowerelectronics,microprocessorsandmicroelectronicsingeneral,andcommunications.Thesetechnologieswillmakethetransmissionanddistributionofelectricitymorereliable,morecontrollable,andmoreefficient.电力公司的输配电系统正在进入一个变革时期。通过电力电子、微处理器和微电子技术以及通信技术的应用，它们的运行达到了前所未有的精细程度。这些技术将使电力的输配更可靠、更可控、更高效。6.1Introduction

ActingfortheUSelectricutilityindustry,theElectricPowerResearchInstitute(EPRI)inPaloAlto,Calif.,hasledthewayinthisareawithseveralthrusts,nottheleastbeingtheflexibleactransmissionsystem,knownintheindustryasFACTS.作为美国电力行业的代表，位于加州帕洛阿尔托的电力研究所(EPRI)已经在这一领域率先推出了几个项目，其中最重要的是灵活的交流输电系统，在业内被称为FACTS。6.1IntroductionPowerelectronicbasedflexibleactransmissionsystem(FACTS)devicesprovideprovensolutionstomeetthesechallenges.Whenusedincombinationwithwideareacontrolsystems(WAMS)itispossibletoincreaseperformancebenefitsfurther.基于电力电子的柔性交流传输系统(FACTS)设备为应对这些挑战提供了成熟的解决方案。当与广域控制系统(WAMS)结合使用时，可以进一步提高性能效益。6.1IntroductionFACTScontrollerscanbeclassifiedbasedonthepowerelectronictechnologyused.Existinginstallationsthatuseline-commutatedthyristorbasedtechnologiesareeitherStaticVarCompensators(SVC)orThyristorControlledSeriesCompensators(TCSC).FACTS控制器可以根据所使用的电力电子技术进行分类。现有的静止无功补偿（SVC）或者可控串联补偿（TCSC）装置使用的都是电网换相的晶闸管技术。6.1IntroductionFACTSdevicescanalsobebasedonvoltagesourceconverters,whichutilizeself-commutateddevicessuchasgateturnoffthyristors(GTO),gatecommutatedthyristors(GCT),orinsulatedgatebipolartransistors(IGBT).FACTS器件还可以基于电压源变换器，其利用自整流器件，如栅极关断晶闸管(GTO)、栅极整流晶闸管(GCT)或绝缘栅双极晶体管(IGBT)。6.1IntroductionExistingVSC-basedFACTSinstallationsusingcanbecategorizedasStaticSynchronousCompensators(STATCOM),UnifiedPowerControllers(UPFC),andConvertibleStaticCompensators(CSC).现有的基于VSC的FACTS装置可分为静止无功发生器(STATCOM)、统一潮流控制器(UPFC)和转换静止补偿器(CSC)。6.1IntroductionInsomeSTATCOMbehaviorisincludedasasecondarycontroloptionindevicessuchaspowerelectronicinterfacesforwindturbines(suchasthefieldcontrolonaDFIG.orthepowerelectronicinterfaceforaenergystoragesystemsuchasabatteryenergystoragesystem(BESS),asuperconductingmagneticenergystoragesystem(SMES)oraflywheelenergystoragesystem.在某些情况下，STATCOM行为被作为二次侧控制选项包含在设备中，如风力涡轮机的电力电子接口(如DFIG上的现场控制)。或用于电池储能系统(BESS)、超导磁性储能系统(SMES)或飞轮储能系统等储能系统的电力电子接口。6.1IntroductionVoltagesourceconverterbasedhighvoltagedirectcurrent(VSC-HVDC)transmissionalsoexhibitsdynamicreactivecontrolcapabilitieswhichareutilizedaswell.基于电压源变换器的高压直流输电也表现出动态无功控制能力。6.1IntroductionTheflexibletransmissionsystemisakintohigh-voltagedcandrelatedthyristordevelopments,designedtoovercomethelimitationsofthepresentmechanicallycontrolledACpowertransmissionsystems.Byusingreliable,high-speedpowerelectroniccontrollers,thetechnologyoffersutilitiesfiveopportunitiestoincreasedefficiency:柔性输电系统的发展类似于高压直流及其相关的晶闸管技术，旨在克服目前机械控制的交流输电系统的局限性。通过使用可靠、高速的电力电子控制器，该技术提供了五个提高效率的契机:6.1Introduction①Greatercontrolofpower,sothatitflowsontheprescribedtransmissionroutes.②Secureloading(butnotoverloadingoftransmissionlinestolevelsnearertheirthermallimits.③Greaterabilitytotransferpowerbetweencontrolledareas,sothatthegenerationreservemargin-typically18percent-maybereducedto15percentorless.①更强的功率控制，使其在指定的传输路线上流动。②确保输电线路的安全负荷(但不能超载)，使其接近其热稳定极限。③更强的控制区域之间的电力转移能力，使发电储备边际从通常的18%降至15%或更低。6.1Introduction④Preventionofcascadingoutagesbylimitingtheeffectsoffaultsandequipmentfailure.⑤Dampingofpowersystemoscillations,whichcoulddamageequipmentand/orlimitusabletransmissioncapacity.④通过限制故障和设备故障的影响来防止级联中断。⑤阻尼可能损坏设备和/或限制可用的传输能力的电力系统振荡。6.1IntroductionAdvantagesandsavingsmustbeweighedagainstthecostofthepowerelectroniccontrollersrequired.AtaboutUS$50-$100perkilovoltampere(kVA)ratingofthethyristor-basedcontrollers,thetypicalcapitalcostofthesecontrollerscanalreadybeaffordedforsomeutilityapplications.(Roughlyspeaking,thecostperkilovoltamperedecreaseswithanincreaseinthesizeofthecontroller.)电力电子控制器的成本必须权衡效率和经济效益。基于晶闸管的控制器的每千伏安(kVA)额定值约为50-100美元，这些控制器的典型资本成本可以由为一些电力企业单位承担。(一般来说，每千伏安的成本随着控制器尺寸的增加而降低。)6.1IntroductionTheflexiblesystemowesitstightertransmissioncontroltoitsabilitytomanagetheinterrelatedparametersthatconstraintoday’ssystems,includingseriesimpedance,shuntimpedance,phaseangle,andtheoccurrenceofoscillationsatvariousfrequenciesbelowtheratedfrequency.灵活的系统将其更严格的传输控制归功于其管理约束当今系统的相关参数的能力，包括串联阻抗、分流阻抗、相位角以及低于额定频率的各种频率的振荡。6.1IntroductionByaddingtoflexibilityinthisway,thecontrollersenableatransmissionlinetofunctionneareritsthermalrating.Forexample,a500-kVlinemayhavealoadinglimitof1000-2000MWforsafeoperation,butathermallimitof3000MW.通过以这种方式增加灵活性，控制器使传输线的功能更接近其额定温度。例如，为了安全运行，500千伏线路的负载限制为1000-2000兆瓦，但热极限为3000兆瓦。6.1IntroductionItisoftennotpossiblebothtoovercometheseconstraintsandtomaintaintherequiredsystemreliabilitybyconventionalmechanicalmeansalone,suchastapchangers,phaseshifters,andswitchedcapacitorsandreactors(inductors).Granted,mechanicalcontrollersareonthewholelessexpensive,buttheyincreasinglyneedtobesupplementedbyrapidlyrespondingpowerelectronicscontrollers.通常不可能既克服这些限制，又仅通过传统的机械手段(如分接开关、移相器、开关电容器和电抗器(电感器))来维持所需的系统可靠性。诚然，机械投切控制器总体上更便宜，但它们越来越需要快速响应的电力电子控制器作为辅助补充。6.1IntroductionThenewtechnologyisnotasingle,highpowerelectroniccontroller,butratheracollectionofcontrollers,whichcanbeappliedindividuallyorcollectivelyinaspecificpowersystemtocontrolthefiveinterrelatedfunctionsalreadymentioned.新技术不是单一的高功率电子控制器，而是控制器的集合，它们可以单独或集体应用于特定的电力系统中，以控制前面提到的五种相互关联的功能。6.1IntroductionThethyristoristheirbasicelement,justasthetransistoristhebasicelementforawholevarietyofmicroelectroniccircuits.Becauseallcontrollersfortheflexibletransmissionsystemareapplicationsofsimilartechnology,theirusewilleventuallybenefitfromvolumeproductionandfurtherdevelopmentofhigh-powerelectronics.晶闸管是它们的基本元件，正如晶体管是各种微电子电路的基本元件一样。由于柔性传动系统的所有控制器都是类似技术的应用，因此它们的使用最终将受益于大批量生产和大功率电子设备的进一步发展。6.1IntroductionElectricpowernetworksintegrategenerationandloadcenterswithineachutilitysystemandsharepowerwithvastregionalgridsthroughinterconnectionsamongneighboringsystems.Thepurposeofthisistotakeadvantageofthediversityofloads,changesinpeakdemandduetoweatherandtimedifferences,theavailabilityofdifferentgenerationreservesinvariousgeographicregions,power-sharingarrangementsamongutilities,shiftsinfuelprices,regulatorychanges,andotherdiscrepancies.电力网络将每个电力系统内的发电和负荷中心整合在一起，并通过相邻系统之间的互连与广大的区域电网共享电力。这样做的目的是利用负荷的多样性、因天气和时差引起的高峰需求的变化、不同地理区域的不同发电储备的可用性、电力公司之间的电力共享安排、燃料价格的变化、监管变化和其他差异。6.1IntroductionByfacilitatingbulkpowertransfers,theseinterconnectednetworkshelpminimizetheneedtoenlargepowerplantsandenableneighboringutilitiesandregionstobuyandsellpoweramongthemselves.Thus,theelectricpowertransmissionnetworkisessentialforreliable,low-costpower.Conversely,inadequatetransmissionwillresultinlessreliable,morecostly.通过促进大规模电力传输，这些相互连接的电网有助于最大限度地减少扩建发电厂的需要，并使邻近的电网和地区能够相互买卖电力。因此，电力传输网络对于可靠、低成本的电力至关重要。相反，传输不足将导致可靠性降低，成本增加。6.1IntroductionThedemandsplacedonthetransmissionnetworkhavegrowninrecentyears,andwillgoongrowing,bothbecausenon-utilitygenerators(NUGs)areenteringthemarketinincreasingnumbersandbecausecompetitionamongtheutilitiesthemselveshasheightened.近年来，对输电网的需求不断增长，而且还将继续增长，这不仅是因为越来越多的自用发电机(UNGs)进入市场，而且因为电力公司之间的竞争加剧。6.1IntroductionMakingmattersworseistheextremedifficultyofacquiringnewrights-of-way.Althoughtheflexibletransmissiontechnologycanalleviatesomeofthesepressures,itmustbestressedthatformuchcapacityexpansion,buildingorupgradingoflineswithoutresortingtoflexibletransmissiontechnologywillstillbethemosteconomicalwaytogo.并且获得新的许可极其困难。虽然柔性传输技术可以缓解这些压力，但必须强调的是，对于大量的容量扩展，不采用柔性传输技术的线路建设或升级仍然是最经济的方式。6.1IntroductionWhatisofmostinteresttothetransmissionplanneristhenewoptionsopenedupbythetechnologyforcontrollingpowerandenhancingtheusablecapacityofpresentlinesthroughvoltageandcurrentupgrading,impedancemodification,andphaseangleregulation.输电规划人员最感兴趣的是，通过电压和电流升级、阻抗修改和相角调节，该技术为控制功率和提高现有线路的可用容量开辟了新的选择。6.1IntroductionAwell-knownformulastatesthatthepowerflowbetweentwopointsalongatransmissionlineisequaltotheproductofthevoltagesatthesepoints,timesthesineofthedifferencebetweentheirphaseangles,alldividedbythetransmissionline’sreactancebetweenthetwopoints.一个众所周知的公式表明，沿传输线两点之间的功率流等于两点电压的乘积，乘以它们相角差的正弦值，再除以两点之间传输线的电抗。6.1IntroductionTounderstandthefreeflowofpower,consideranelementarycaseinwhichtwogeneratorsaresendingpowertoaloadcenterthroughanetworkconsistingofthreelinesinameshedconnection[Fig.6.1].为了理解电力的自由流动，考虑一个基本的情况，两台发电机通过一个由三条线组成的网格连接网络向负荷中心供电[图6.1]。6.1IntroductionFig.6.1freeflowofpowerinsimplestructuregrid图6.1简单结构网格中功率的自由流动6.1IntroductionThelinesAB,BC,andAChavecontinuousratingsof1000Mw,1250Mw,and2000Mwrespectivelywithemergencyratingsoftwicethosefigures.Ifonegeneratorisratedat2000MWandtheotherat1000Mw,atotalof3000Mwwouldbedeliveredtotheloadcenter.Fortheimpedancesshown,thethreelinesshouldcarry600,1600,and1400Mw,respectively.Suchasituationwouldoverloadoneline.AB、BC和AC线路的连续额定功率分别为1000MW、1250MW和2000MW，应急额定功率是这些数字的两倍。如果一台发电机的额定功率为2000MW，另一台发电机的额定功率为1000MW，则总共将向负荷中心输送3000MW的电力。对于所示的阻抗，三条线路应分别承载600、1600和1400MW。这种情况会使一条线路超负荷。6.1IntroductionPower,inshort,flowsinaccordancewithtransmissionlineimpedancesthatbearnodirectrelationshiptotransmissionownership,contracts,orthermallimits.Thedifferencebetweenthefree-flowpathandthecontractpathiscalled“loopflow,”andisusuallycharacterizedbyacirculationofpowerthatleavestheavailablecapacityunderutilized.简而言之，电力根据输电线路阻抗流动，与输电所有权、合同或热限制没有直接关系。自由流动路径和合同路径之间的差异称为"环流"，通常表现为电力循环，导致可用容量利用不足。6.1IntroductionIf,however,acapacitorwhosereactanceis-5Ωatthesynchronousfrequencyisinsertedinoneline[Fig.1,topright],itreducestheline’simpedancefrom10Ωto5Ω,sothatpowerflowthroughthelineswillbe250,1250,and1750Mwrespectively.然而，如果在一条线路上插入一个在同步频率下电抗为-5Ω的电容器[图1，右上]，则线路的阻抗从10Ω减小到5Ω，从而流经线路的功率将分别为250、1250和1750MW。6.1IntroductionItisclearthatiftheseriescapacitorisadjustable,thenotherpower-flowlevelsmayberealizedinaccordancewiththeownership,contract,andthermallimitations.Thiscapacitorcouldbemodularandmechanicallyswitched.butthenumberofoperationswouldbeseverelylimitedbyweironthemechanicalcomponents.显然，如果串联电容器是可调的，那么就可以根据所有权、合同和热限制实现其他功率流水平。这种电容器可以采用模块化和机械切换的方式。但机械部件上的气动触头会严重限制操作次数。6.1IntroductionOthercomplicationsmayarise.Aseriescapacitorinalinemayleadtosub-synchronousresonance,typicallyat15-30Hz.Thisresonanceoccurswhenthemechanicalresonancefrequencyoftheshaftofthegeneratorcoincideswith60Hzminustheelectricalresonancefrequencyofthecapacitorinserieswiththetotalsystemimpedance.其他问题也可能出现。线路中的串联电容可能导致次同步谐振，通常为15-30Hz。当发电机轴的机械谐振频率等于电网的60Hz减去串联补偿产生的电磁谐振频率时，就会发生这种谐振。6.1IntroductionIfsuchresonancepersists,itsoondamagestheshaft.Furthermore,whiletheoutageofonelineisforcingotherlinestooperateattheiremergencyratingsandcarryhigherloads,power-flowoscillationsatlowfrequency(typically1-2Hz)maycausegeneratorstolosesynchronism,perhapspromptingthesystem’scollapse.如果这种共振持续下去，很快就会损坏轴。此外，当一条线路的中断迫使其他线路以其紧急额定运行并承载更高的负载时，低频(通常为1-2Hz)的潮流振荡可能会导致发电机失去同步，可能会导致系统崩溃。6.1IntroductionIftheseriescapacitoristhyristorcontrolled,itcanbeoperatedasoftenasrequiredandcanbemodulatedsorapidlytodampanysub-synchronousresonanceconditions,aswellaslow-frequencyoscillationsinpowerflow,andallowthetransmissionsystemtogofromonesteadystateconditiontoanotherwithoutdamagetoageneratorshaftorthecollapseofthesystem.如果串联电容器由晶闸管控制，则可根据需要频繁运行，并可快速调制，以抑制任何次同步谐振情况以及功率流中的低频振荡，并使输电系统从一种稳定状态进入另一种稳定状态，而不会损坏发电机轴或导致系统崩溃。6.1IntroductionInotherwords,athyristor-controlledseriescapacitorcangreatlyenhancethestabilityofthenet-work.Moreoftenthannot,though,itismostpracticalforpartoftheseriescompensationtobemechanicallycontrolledandpartthyristorcontrolled,soastocounterthesystemcontraintsatleastcost.换句话说，晶闸管控制的串联电容器可以大大提高网络结构的稳定性。不过，最实际的做法往往是部分串联补偿由机械控制，部分由晶闸管控制，以便以最低成本应对系统限制。6.1IntroductionSimilarresultsmaybeobtainedbyincreasingtheimpedanceofoneofthelinesinthesamemeshedconfigurationbyinsertinga7Ωreactor(inductor)inserieswiththeline[Fig.6.1].Again,aseriesinductorthatispartlymechanicallyandpartlythyristorcontrolledcouldservetoadjustthesteady-statepowerflowsaswellasdampunwantedoscillations.通过与线路串联插入7Ω电抗器(电感)来增加同一网格结构下其中一条线路的阻抗，也可以得到类似的结果[图6.1]。同样，部分机械和部分晶闸管控制的串联电感可以用来调节稳态功率流以及阻尼不必要的振荡。6.1IntroductionIneithercase,athyristor-controlledphaseangleregulatorcouldbeinstalledinsteadofaseriescapacitororaseriesreactorinanyofthethreelinestoservethesamepurpose.Notethatneithertheinductornorthephaseangleregulatorcontributestosubsynchronousresonance.在任何一种情况下，一个可控硅控制的相角调节器可以代替串联电容器或串联电抗器安装在任何三条线路，以达到相同的目的。注意，无论是电感器还是相角调节器都不会产生次同步谐振。6.1IntroductionAtlowerrightinFig.6.1,theregulatorisinstalledinthethirdlinetoreducethetotalphaseangledifferencealongthelinefrom8.5degreesto4.2degrees.Asbefore,acombinationofmechanicalandthyristorcontrolinthephaseangleregulatormayminimizecost.在图6.1右下方，调节器安装在第三条线路上，将沿线的总相角差从8.5度减小到4.2度。如前所述，在相角调节器中结合使用机械控制和晶闸管控制可最大限度地降低成本。6.1IntroductionSeveralcontrollersarepresentlybeingevaluatedforflexibletransmissionsystems,whileothershavebeenconceptualizedbutnotyetdeveloped.Whatmightbecalledthefirstgenerationofcontrollersincludestwothyristor-basedsystemsthathavebeenusedinsomeutilitysystemsforseveralyears.目前正在对用于柔性输电系统的几种控制器进行评估，而其他控制器虽已概念化，但尚未开发。第一代控制器包括两个基于晶闸管的系统，已在一些电力系统中使用了数年。6.1IntroductionThefirst,astaticvarcompensator(SVC)hasbeenusedsincethel970s.Itaddressestheproblemofkeepingsteady-stateanddynamicvoltageswithinbounds,andhassomeabilitytocontrolstability,butnonetocontrolactivepowerflow.TheSVCusesthyristorvalvestoaddorremoveshunt-connectedreactorsand/orcapacitorsrapidly,oftenincoordinationwithmechanicallycontrolledreactorsand/orcapacitors.第一种是静态无功补偿器(SVC)，自20世纪70年代以来一直使用。它解决了保持稳态电压和动态电压在一定范围内的问题，具有一定的稳定控制能力，但没有控制有功潮流的能力。SVC使用晶闸管阀快速投入或切除并联电抗器和/或电容器，通常与机械控制的电抗器和/或电容器配合使用。6.1IntroductionThefirstapplicationofanSVCtovoltagecontrolwasdemonstratedontheTri-StateG&TSystemin1977byGeneralElectricCo.(GE),whichisheadquarteredinFairfield,Conn.1977年，总部位于康涅狄格州费尔菲尔德的通用电气公司（GE）在三州G&T系统上首次展示了SVC在电压控制方面的应用。6.1IntroductionAnotherSVCwithvoltageandstabilitycontrol,developedwithEPRIfundingbyWestinghouseElectricCorp.ofPittsburghbeganoperationin1978ontheMinnesotaPowerandLightSystem.(incidentally,sinceEPRI’slaunchingoftheflexibleactransmissionsystemstrategyin1986,themarketforSVCshasincreasedsubstantially.)在EPRI的资助下，由匹兹堡西屋电气公司开发的另一款具有电压和稳定性控制功能的SVC于1978年开始在明尼苏达电力和照明系统上运行（顺便提一下，自EPRI于1986年推出灵活交流输电系统战略以来，SVC的市场大幅增长）。6.1IntroductionThesecondcontrollerinactualuseistheNGH-SSRDamper,invertedtocountersub-synchronousresonance(SSR).SSRinstabilitiesareattimesanundesirablesideeffectofusingamechanicallycontrolledseriescapacitortoaddupto80percentcompensationtoatransmissionline,thegoalbeingtolowertheline’simpedance,increasepowerflow,andexpandstabilitylimits.实际使用中的第二种控制器是NGH-SSR阻尼器，可反转以对抗次同步谐振（SSR）。SSR不稳定性有时是使用机械控制串联电容器为输电线路增加高达80%补偿，其目的是降低线路阻抗、增加潮流和提高稳定性极限。6.1IntroductionIntheearly1970s,aftertheshaftofaturbinegeneratorbelongingtoSouthernCaliforniaEdisonCo.wasdamagedbysub-synchronousresonance,theseriescompensationlevelonamajor500-kVtransmissioncorridorhadtobereduced,sothatlesspowercouldbetransferredoverit.20世纪70年代初，在南加州爱迪生公司的一台涡轮发电机的轴因次同步谐振而损坏后，一条主要的500千伏输电走廊上的串联补偿电压不得不降低，从而减少了通过该走廊传输的电力。6.1IntroductionSincethen,varioussolutionstotheproblemsofsensingsub-synchronousresonance,emergency-switching,blockingit,andsoon,havebeenadopted.此后，针对亚同步谐振的感应、紧急切换、阻断等问题，人们采取了各种解决方案。6.1IntroductionTheNGH-SSRdamperconsistsofathyristoracswitch(back-to-backthyristors)connectedinserieswithasmallinductorandresistoracrosstheseriescapacitor.Theoperationofthedamperisbasedontwoprinciples.Oneistofiretheswitch8.33msaftereachzeroofthecapacitor’svoltage,orhalfacycle(or180degrees)at60Hz.NGH-SSR阻尼器由一个晶闸管交流开关（双向晶闸管）串联一个小电感电阻后再与一个串联电容器并联构成。阻尼器的运行基于两个原理。其一是在电容器电压每次为零后8.33毫秒或60赫兹的半个周期（或180度）启动开关。6.1IntroductionButifthevoltagewavecontainsotherfrequencies,somehalfcycleswillbelongerthan8.33ms.Inthiscasethevalvefiringat8.33mscausessomecurrenttoflowduringtheextendedpartofthehalfcycleanddampstheoscillations.Thesecondprincipleistofiretheswitchsomewhatearlierthan8.33ms,orlessthan180degreesfollowingthezero.但如果电压波形包含其他频率，则某些半周期将长于8.33毫秒。在这种情况下，阀门在8.33毫秒发射导致一些电流在半周期的延长部分流动，并抑制振荡。第二个原则是启动开关稍早于8.33毫秒，或小于零后180度。6.1IntroductionEarlierfiringcausestheimpedanceofthecombinedcircuittobemorenegativethanthatwiththecapacitoralone,thusdetuningtheelectriccircuit.Furthermore,bythemodulationofthefiringangle,theimpedancecanhaveapowerfuldampingeffectatanyunwantedfrequencybelowthemainfrequency.提前启动会使组合电路的阻抗负值大于单独使用电容器时的阻抗负值，从而使电路失谐。此外，通过调节启动角度，阻抗可在主频以下的任何不需要的频率上产生强大的阻尼效应。6.1IntroductionInanSSRdamperinstalledinSouthernCaliforniaEdison’sLugosubstation[Fig.6.2],thethyristorshaveamodestcurrentrating(15percentofload)forcontinuouslybypassingthecapacitor’swaveforonlyuptothelast10degreesorsoofthevoltagewave.Withmorecoolingofthethyristorsandappropriatesizingofthereactororresistorinserieswiththethyristorswitch,thisdamperformsthebasisforthefullyratedthyristor-controlledseriescapacitordescribedlater.在安装在南加州爱迪生公司卢戈变电站的SSR阻尼器中[图6.2]，晶闸管具有有限的额定电流(负载的15%)，可以连续通过电容器的波，直到电压波的最后10度左右。随着晶闸管的更多冷却和与晶闸管开关串联的电抗器或电阻器的适当尺寸，该阻尼器形成了后面描述的定晶闸管控制串联电容器的基础。6.1IntroductionFig.6.2Resonancedamperanditsapplication图6.2共振阻尼器及其应用6.1IntroductionWiththerecognitionofflexibleactransmissiontechnologyasahighlyeffectivemeansofenhancingpowersystems,asecondgenerationofcontrollersisbegtoemerge.Aboutadozenthyristor-basedsystemshavebeenidentifiedaslikelytoimprovetheperformanceofanacsystem.SixarebeingpursuedfordevelopmentaspartofEPRI’sproposed10-yearcollaborativeR&Dplanforthetechnology.随着人们认识到灵活的交流输电技术是提高电力系统性能的有效手段，第二代控制器开始出现。目前已确定约有十几种基于晶闸管的系统有可能提高交流系统的性能。作为EPRI提出的该技术10年合作研究与开发计划的一部分，目前正在开发六种系统。6.1IntroductionObviously,Mostvitaltopowerandstabilitycontrolistheabilitytocontrolimpedanceorphaseangle.Sincetheseriesimpedanceofatypicaltransmissionlineismostlyinductive,withonly5-10percentresistive,itisconvenienttocontrolapowersystem'ssteady-stateimpedancebyaddingbothathyristor-controlledseriescapacitorandathyristor-controlledseriesreactor(inductor).显然，对于功率和稳定性控制而言，最重要的是控制阻抗或相角的能力。由于典型输电线路的串联阻抗大多为感性阻抗，只有5-10%是阻性的，因此可以很方便地通过增加晶闸管控制的串联电容器和晶闸管控制的串联电抗器来控制电力系统的稳态阻抗。6.1IntroductionSincethecapacitorisanegativeimpedance,theintroductionofavariableseriescapacitormeansavariablenegativeimpedanceinserieswiththeline'snaturalpositiveimpedance.由于电容器是一个负阻抗，因此引入一个可变串联电容器意味着在线路的自然正阻抗上串联了一个可变负阻抗。6.1IntroductionThusthethyristor-controlledseriescapacitorcanvarytheimpedancecontinuouslytolevelsbelowanduptotheline'snaturalimpedance.Ontheotherhand,addingathyristor-controlledseriesreactormeansaddingavariablepositiveimpedancetoavalueabovetheline'snaturalpositiveimpedance.因此，晶闸管控制的串联电容器可以连续改变阻抗，使其达到低于和高于线路自然阻抗的水平。另一方面，增加晶闸管控制的串联电抗器意味着增加一个可变的正阻抗，其值高于线路的自然正阻抗。6.1IntroductionOnceinstalled,itwilleitherrespondrapidlytocontrolsignalstoincreaseordecreasethecapacitanceorinductance,therebydampingthosedominantoscillationfrequenciesthatwouldotherwisebreedinstabilitiesorunacceptabledynamicconditionsduringandafteradisturbance.安装后，它将对控制信号做出快速反应，增大或减小电容或电感，从而抑制那些主要的振荡频率，否则在扰动期间和扰动之后，这些频率将导致不稳定或不可接受的动态条件。6.1IntroductionThefirstofthenewcontrollerstobedemonstratedonautilitytransmissionsystemisthethyristor-controlledseriescapacitor(TCSC).In1991,AmericanElectricPowerCo.ofColumbus,Ohio,begantestingaprototypeswitchononephaseoftheseriescapacitorbankatits345-kVKanawhaRiverSubstationinWestVirginia.晶闸管控制串联电容器(TCSC)是第一个在电网输电系统上演示的新型控制器。1991年，俄亥俄州哥伦布市的美国电力公司开始在其位于西弗吉尼亚州的345千伏卡纳瓦河变电站的串联电容器组的一个相上测试原型开关。6.1IntroductionTheswitchwassuppliedbyAseaBrownBoveri,Vasteras,Sweden.Althoughtheswitchisnotstrictlyspeakingathyristorcontrolledseriescapacitorandthetestinstallationisonlysinglephase,therapidswitchingofcapacitorsegmentsinandoutofthecircuitdotestthekeyhardware.Insomeapplications,thethyristor-basedswitchingisjustifiableforitsreliabilityandspeed.开关由瑞典瓦斯塔斯的AseaBrownBoveri公司提供。虽然从严格意义上讲，开关并不是晶闸管控制的串联电容器，而且测试装置也只是单相的，但电容器在电路中的快速开关确实对关键硬件进行了测试。在某些应用中，基于晶闸管的开关因其可靠性和速度而具有合理性。6.1IntroductionInoctober1992,theWesternAreaPowerAdministration(WAPA),Golden,Colo.,dedicatedthefirstthree-phasethyristor-controlledseriescapacitorinstallation.ItwasbuiltbyMunich-basedSiemensAGandinstalledattheWAPAKayentaSubstationinArizonaina300-km,230-kV,300-MWtransmissionline.1992年10月，位于科罗拉多州戈尔登市的西部地区电力管理局（WAPA）投入使用了第一套三相晶闸管控制串联电容器装置。该装置由总部位于慕尼黑的西门子公司制造，安装在亚利桑那州WAPAKayenta变电站的一条300公里、230千伏、300兆瓦的输电线路上。6.1IntroductionTheinstallationincludesthreesegments:one15-Ω,one40-Ω,andone55-Ωseriescapacitorbank.Onlythe15-Ω(45-MVA)bankisthyristorcontrolled.Thisinstallationisapioneeringstepbecausethe15Ωbankcanbecontrolledsmoothlyandrapidlyfrom15Ωto60ΩthroughthecontrolledfiringangleofthethyristorvalvesasintheNGHsub-synchronousresonancedamper,butoverawiderrange,from145degreesto180degrees.该装置包括三个部分：一个15Ω、一个40Ω和一个55Ω的串联电容器组。只有15Ω（45-MVA）的电容器组采用晶闸管控制。这一装置具有开创性意义，因为与NGH亚同步谐振阻尼器一样，通过可控晶闸管阀的触发角，15Ω电容器组可以平稳、快速地从15Ω控制到60Ω，但控制范围更广，从145度到180度不等。6.1IntroductionTheinstallationallowsthetransmissionlinecapacitytobeincreasedfrom300MWto400MW.安装后，输电线路的容量可从300兆瓦增至400兆瓦。6.1IntroductionTheconstructionofalargethree-phasethyristor-controlledseriescapacitorinstallationona500-kVlineisinprogressattheSlattSubstationofBonnevillePowerAdministration(BPA)inOregon.(ThisBPAlineisconnectedtoPortlandGeneralElectricCo.'sBoordmanpowerplantinOregon.)Theinstallationfeaturesafullrangeofcontrolsandoperatingrequirements.俄勒冈州邦纳维尔电力管理局(BPA)的Slatt变电站正在一条500千伏线路上安装大型三相晶闸管控制串联电容器。(该