RLEVELFUZZYCONTROLLERTheconventionalPIDcontrollerhasapoorcontrolperformancetothesteamgeneratorthatexist“falsewaterlevel”characteristics,showingagreaterovershootinthetrackingtime.Butawell-designedfuzzycontrollerisabletoovercomethe"falsewaterlevel"phenomenon,andhasgoodcontrolperformance.A.SstructureofFuzzyControllerThestructureshowedinFigure.Figure.Structureofsteamgeneratorwaterlevelfuzzycel；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.Thisphenomenoniscalled"falsewaterlevel"phenomenon.III.DESIGNOFWATERLEVELFUZZYCONTROLLERTheconventionalPIDcontrollerhasapoorcontrolperformancetothesteamgeneratorthatexist“falsewaterlevel”characteristics,showingagreaterovershootinthetrackingtime.Butawell-designedfuzzycontrollerisabletoovercomethe"falsewaterlevel"phenomenon,andhasgoodcontrolperformance.A.SstructureofFuzzyControllerThestructureshowedinFigure.Figure.Structureofsteamgeneratorwaterlevelfuzzyc靠蒸汽流量和给水流量匹配来维持。可以将水位随蒸汽流量或者给水流量变化而变化看作一个简单一体化过程，蒸汽流量变化和给水流量变化对水位影响又是不同。()给水流量扰动下动态特性假设蒸汽流量保持不变，而给水流量阶跃增加，一方面，由于新增给水温度要比蒸汽发生器中饱和水温度低很多，因此，当新水进入后就会吸收大量额外热量，水中气泡含量大大减少，从而导致水位下降；另一方面，给水流量大于蒸汽负荷，引起水位线性增加。综合以上两点，当给水阶跃增加，水位增长会有一个延迟过程，表现为先下降后上升。()蒸汽负荷扰动下动态特性假设给水流量保持不变，蒸汽负荷阶跃增加，一方面，由于蒸汽流速比给水流速大，水位会下降；另一方面，随着蒸汽负荷增加，内部蒸汽压力降低，液面气泡容积增加，从而引起水位增加。综合以上两个因素，当蒸汽流量阶跃增加以后，水位下降会有一个延迟过程，表现为先上升后下降。给水流量或者蒸汽流量阶跃减少对水位影响与上述有相似原理。综上所述，当给水流量或者蒸汽负荷变化，水位不会立即跟随变化，开始会出现一个相反过程。这个现象就称为“虚假液位”现象。.水位模糊控制器设计传统PID控制器对于蒸汽发生器水位控制效果不佳，存在“虚假液位”现象，表现为跟踪设定值时有较大超调。但是，一个设计合理模糊控制器能够克服“虚假液位”现象，有较好控制效果。()模糊控制器结构模糊控制器结构如图所示。图蒸汽发生器水位模糊控制器结构选择水位偏差（e）和偏差变化率（ec）作为模糊控制器输入，模糊控制器输出量为阀门开度增量信号Δu。同时，以蒸汽流量作为前馈信号来克服“虚假液位”现象，以给水流量作为内反馈信号来克服给水波动。k，k是给水流量和蒸汽流量传感器转换系数。为了保证给水流量等于蒸汽流量，k和k应该相等。()模糊理论、模糊子集和隶属函数e、ec和u模糊论域是[-,]，用NB（负大）、NM（负中）、NS（负小）、ZO（零）、PS（正小）、PM（正中）和PB（正大）个模糊子集描述。e，ec和Δu都采用三角形隶属函数（如图）。FuzzycontrollerKvalveGW(s)dx/dtKGS(s)expectedwaterleverStreamflowWaterleverwaterfloweec+-++-+++图输入输出隶属函数()模糊控制规则列表模糊控制规则建立原则是：当偏差大，输出控制量应该优先以尽快消除偏差为主；当偏差小，输出控制量应优先消除超调。当偏差变化率为负，这表明水位有上升趋势，如果此时水位高，应减小阀门开度；相反，应就应当开大阀门。通过专业分析，建立如表所示规则表。表模糊控制规则表()模糊推理和模糊判决本次设计模糊推理系统采用Mamdani型。模糊推理系统基本属性设置为：“与”算法为取小算法；“或”算法为取大算法。模糊蕴含采用取小算法；模糊综合采用取大算法；清晰化采用重心法。eecNBNMNSZOPSPMPBNBNBNBNMNMNSNSZONMNBNMNMNSNSNSZONSNMNMNSNSZOPSPSZONMNSNSZOPSPSPMPSNSNSZOPSPSPMPMPMNSNSZOPSPSPMPMPBZOPSPSPMPMPBPB.仿真实例中国秦山核电站一个压水堆蒸汽发生器有如下实验模型：,)(.))((.,))((.)()(PsssssePsssseesGsGsssp,.)(.)(PsssssesG其中，Ps表示额定负荷。当负荷为~Ps时，用公式()和()，当负荷小于Ps时，用公式()和()。图预期水位阶跃响应图控制系统系数k=k=.。给水控制阀是一个线性阀，增益为。e和ec量化因子分别为和，u比例因子为.。仿真时，我们限定给水流量范围在kg/s到额定流量kg/s。假设预期水位从m上升到m，水位响应如图中实线所示。为了比较模糊控制器增加效果，我们也作出传统PID控制仿真结果。可以看出，与传统PID控制相比，模糊控制在超调量、调节时间和稳态特性方面有重要改善。.结论本论文针对蒸汽产生器大延迟和模型不确定特性，设计了一个水位模糊控制系统。我们还给出了秦山核电站蒸汽发生器仿真，并获得了令人满意效果。这种方法同样适用于其它大滞后和非线性系统控制模型，具有广阔应用前景。el；QWforthewaterflow；QSforthesteamflow；GW(s)fortheimpactofthewterflowtothesteamgeneratorwaterlevel；GS(s)fortheeffectofthesteamflow(load)tothesteamgeneratorwaterlevel.Thebalanceofthesteamgeneratorwaterlevelismaintainedthroughthematchbetweenthewaterflowandsteamflow.Theprocessthatwaterlevelchangeswiththesteamfloworwaterflowchangingcanberegardedasasimpleintegrationprocess,butimpactofthewaterflowandst学号南湖学院毕业设计（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),InternationalConferenceonDateofConference:-Aug.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：..ResearchonFuzzyControlforSteamGeneratorWaterLevelI.INTRODUCTIONThesteamgeneratorisoneofthemaindevicesinPWRnuclearpowerplant,inordertoensurethesafetyofnuclearpowerplantduringoperation；thesteamgenerator‟swaterlevelmustbecontrolledinacertainrange.Whenthenuclearpowerplantisrunning,asthesteamfloworthewaterflowchanging,theamountofboilingbubblesinthesteamgeneratorwillchangeduetolocalpressureortemperaturechange,theinstantaneouswaterlevelshowed“falsewaterlevel”phenomenon.Theexistenceof“falsewaterlevel”madeitdifficulttocontrolthewaterlevel.Theintroductionoffeed-forwardcontroltothetraditionalsingle-loopPIDcontrolcan,inacertainextent,overcomethe"falsewaterlevel"phenomenon.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)（）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        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.INTRODUCTIONThesteamgenerator

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