附录-外文科技论文翻译-中英文

学号24081900389南湖学院毕业设计（论文）英文翻译英文题目：ResearchonFuzzyControlforSteamGeneratorWaterLevel中文题目：蒸汽发生器水位模糊控制研究文献出处：Computer,Mechatronics,ControlandElectronicEngineering(CMCE),2010InternationalConferenceonDateofConference:24-26Aug.2010作者姓名：Pengwei译者姓名：杨胜专业：机械设计制造及其自动化完成时间：2012.5.25ResearchonFuzzyControlforSteamGeneratorWaterLevelI.INTRODUCTIONThesteamgeneratorisoneofthemaindevicesinPWRnuclearpowerplant,inordertoensurethesafetyofnuclearpowerplantduringoperation;thesteamgenerator’swaterlevelmustbecontrolledinacertainrange.Whenthenuclearpowerplantisrunning,asthesteamfloworthewaterflowchanging,theamountofboilingbubblesinthesteamgeneratorwillchangeduetolocalpressureortemperaturechange,theinstantaneouswaterlevelshowed“falsewaterlevel”phenomenon.Theexistenceof“falsewaterlevel”madeitdifficulttocontrolthewaterlevel.Theintroductionoffeed-forwardcontroltothetraditionalsingle-loopPIDcontrolcan,inacertainextent,overcomethefalsewaterlevelphenomenon.ButtheconventionalPIDcontrolmethodintheprocessofsteamgeneratorwaterlevelcontrolhassomeshortcomings.Tothesteamgeneratorthathashighlycomplex,largetime-delayandnonlineartime-varyingcharacteristics,thePIDparameterstuningisatediousjobandthecontroleffectisverypoor.Furthermore,toachievegoodcontrolperformancestillasconditionschanging,itoftenneedstochangethePIDcontrollerparameters.ButtheanalogPIDcontrollerparametersaredifficulttoregulateonline.Fuzzycontrolisakindofnonlinearcontrolstrategybasedonfuzzyreasoning,whichexpressoperatingexperienceofskilledmanipulationmenandcommonsenserulesofinferencethroughvaguelanguage.Fuzzycontroldonotneedtoknowprecisemathematicalmodelofcontrolledobject,isnotsensitivetothechangeofprocessparameters,ishighlyrobustandcanovercomenon-linearfactors,so,fuzzycontrolhasfasterresponseandsmallerultra-tone,cangetbettercontroleffect.Basedonunderstandingabove,thispaperdesignasteamgeneratorwaterlevelfuzzycontroller,thesimulationshowsthatthecontrollerhasgoodcontrolperformanceandpracticalvalue.II.DYNAMICCHARACTERISTICSOFSTEAMGENERATORThetransferfunctionofPWRsteamgenerator’smathematicalmodelofthegeneralformshowsbelow:y(s)=GW(s)QW(s)+GS(s)QS(s)（1）whereyisthesteamgeneratorwaterlevel;QWforthewaterflow;QSforthesteamflow;GW(s)fortheimpactofthewaterflowtothesteamgeneratorwaterlevel;GS(s)fortheeffectofthesteamflow(load)tothesteamgeneratorwaterlevel.Thebalanceofthesteamgeneratorwaterlevelismaintainedthroughthematchbetweenthewaterflowandsteamflow.Theprocessthatwaterlevelchangeswiththesteamfloworwaterflowchangingcanberegardedasasimpleintegrationprocess,butimpactofthewaterflowandsteamflow‘schangeonwaterlevelisdifferent.A.DynamicsCharacteristicsunderWaterFlowDisturbanceSupposesteamflowGSremainsunchanged,andwaterflowGWstepincreases,ontheonehandbecausethetemperatureoffeedwaterismuchlowerthanthetemperatureofsaturatedwaterinthesteamgenerator,sothat,whenfeedwaterentering,itwillabsorbalotofextraheat,thevaporphasebubblecontentswillreduce,resultinginwaterleveldecreasing;ontheotherhand,theincreaseinwaterflowGWmadeitgreaterthansteamload,andcausewaterlevelincreaseslinearly.Comprehensivetwofactors,afterthestepincreaseofthewaterflow,thewaterlevelrisehasatimedelayprocess,showingadownthenup.B.DynamicCharacteristicsunderSteamLoadDisturbanceSupposefeedwaterflowGWremainsunchanged,andsteamloadGSstepincreases,ontheonehandthewaterlevelwillflowdownbecausethesteamflowrateisgreaterthanthewaterflowrate.Ontheotherhand,asthesteamloadincreased,vaporpressureisreduced;thebubblevolumeontheliquidsurfaceincreases,causingthewaterlevelincreased.Comprehensivetwofactors,afterthestepincreaseofthesteamflowrate,thewaterleveldownhasatimedelayprocess,showingaupthendown.Theimpactonthewaterlevelofwaterfloworsteamflowsteppingdecreasedhassimilarprincipleasabove.Asanalysiscanbeseenasabove,whenthewaterfloworsteamloadchange,thewaterleveldidnotfollowthechangeimmediately,butthereisanoppositeprocessatfirst.Thisphenomenoniscalledfalsewaterlevelphenomenon.III.DESIGNOFWATERLEVELFUZZYCONTROLLERTheconventionalPIDcontrollerhasapoorcontrolperformancetothesteamgeneratorthatexist“falsewaterlevel”characteristics,showingagreaterovershootinthetrackingtime.Butawell-designedfuzzycontrollerisabletoovercomethefalsewaterlevelphenomenon,andhasgoodcontrolperformance.A.SstructureofFuzzyControllerThestructureshowedinFigure1.Figure1.StructureofsteamgeneratorwaterlevelfuzzycontrollerChoosethewaterlevelerror(e)andchangerateoferror(ec)asinputofthefuzzycontroller,theoutputofthefuzzycontrolleristheaddedvalueofthevalveopeningsignalΔu.Meanwhile,usethesteamflowfeed-forwardtoovercomethefalsewaterlevelphenomenon,usewaterflowfeedbacktoovercomefluctuationsinwatersupplyside.k1,k2werewaterflowandsteamflowtransmitterconversionfactor.Toensurethewaterflowtomatchthesteamflow,k1andk2valuesshouldbeequalto.B.Fuzzytheory,fuzzysubsetandMembershipFunctionThefuzzyAnalectsofe,ecanduare[-6,6],bothwithsevenfuzzysetsNB(negativebig),NM(negativemiddle),NS(negativesmall),ZO(zero),PS(positivesmall),PM(positivemiddle)andPB(positivebig)todescribe.e,ecand,Δuareallusingtriangularmembershipfunction(seeFigu