plc供水外文文献.docx
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plc供水外文文献
TransducerandPLCinthewatercontrolsystemapplications
M.BaniYounisandG.Frey
JuniorprofessorshipAgentenbasedAutomation
UniversityofKaiserslautem
P.0.Box3049,D-67653Kaiserslautem,Germany
1.Introduction
Currently,thewaterlevelcontrolinalargepartoftheelectricalpumpsarenottowinggearshiftsystem,nogearshiftmostoftheelectricalenergyconsumedinthewatersupplytothefrequentchangesinthepumpsstopped.Thisnotonlymakestheelectricalworkininefficientzones,cutshorttheusefullifeofelectricalandelectricalequipmentforthefrequentfailuretostopthehighrate,leadingtoseriouswasteofwaterresources,systemmaintenance,repairslargerworkload.
Withhighlivingwaterandindustrialwatergraduallyincreased,thetraditionalcontrolmethodsthatareoutdated.Originallyusedforartificialwaterlevelcontrol,waterlevelduetothelackofaccuratepositioninghourmonitoring,itisdifficulttoaccuratelycontrolthepumpshavestopped;Usingbuoysormechanicalcontroldevicessuchaswatersupplysituationhasmadesomechanges,butbecauseofmechanicalfailuremoredevices,poorreliabilitytomaintenancewillfacegreattrouble.
Frequencyconversiontechnology,withitssuperiorityintheareaofenergyefficiencyandHengyapressurecontrolsystemcanbesolvedbytheexistenceoftheaboveproblems.ConsiderselectingChanpianjiorPlcandtransducercombinationatthecoreofthesystemcanachieveabettercontrolresults.Butinsoftwaredesign,PlcprogrammingofmorethanShanpianjiconcise,andvisual;Fromthehardwareinterfaceconsiderations,Shanpianjicircuitslightlycomplex;Fromtheeconomicconsiderations,thePlcprocessesaremature,costandsmallPlcShanpianjialittle,becausethesystemparameterstobeadjustedinaccordancewiththesituationontheground,Plcsoftware,thetimeparametersadjustmentssimpler,somoreconducivetoafter-salepersonnel.
ProgrammableLogicControllers(PLCs)areaspecialtypeofcomputersthatareusedinindustrialandsafetycriticalapplications.ThepurposeofaPLCistocontrolaparticularprocess,oracollectionofprocesses,byproducingelectricalcontrolsignalsinresponsetoelectricalprocess-relatedinputssignals.ThesystemscontrolledbyPLCsvarytremendously,withapplicationsinmanufacturing,chemicalprocesscontrol,machining,transportation,powerdistribution,andmanyotherfields.Automationapplicationscanrangeincomplexityfromasimplepaneltooperatethelightsandmotorizedwindowshadesinaconferenceroomtocompletelyautomatedmanufacturinglines.
Withthewideningoftheirapplicationhorizon,PLCprogramsarebeingsubjecttoincreasedcomplexityandhighqualitydemandsespeciallyforsafety-criticalapplications.ThegrowingcomplexityoftheapplicationswithinthecomplianceoflimiteddevelopmenttimeaswellasthereusabilityofexistingsoftwareorPLCmodulesrequiresaformalapproachtobedeveloped[I].Ensuringthehighqualitydemandsrequiresverificationandvalidationproceduresaswellasanalysisandsimulationofexistingsystemstobecarriedout[2].OneoftheimportantfieldsfortheformalizationofPLCprogramsthathavebeengrowingupinrecenttimeisReverse-engineering[3].ReverseEngineeringisaprocessofevaluatingsomethingtounderstandhowitworksinordertoduplicateorenhanceit.WhilethereuseofPLCcodesisbeingestablishedasatoolforcombatingthecomplexityofPLCprograms,ReverseEngineeringissupposedtoreceiveincreasedimportanceinthecomingyearsespeciallyifexitinghardwarehastobereplacedbynewhardwarewithdifferentprogrammingenvironments
TransducerinthewatersysteminconjunctionwiththeintroductionofsmallPlctechnologynotonlychangethetraditionaluseofwatercontrolvalves,andinenergyconservation,Hengyacontrol,areverygoodresults,thepaperintroducedatransducer--PLCcontroltechnologyinthepumpcontrolapplications.
2.Systemcontroltheoryandcomposition
1.constantpressurewatersystembasicworkingprinciple
SystemusesAutomaticFrequencyControlregulationorpumpmotorspeed.Plusorminuspump.ItisprimarilybytheFrequencyControlSystem.PIDregulator,pressuresensors,liquidlevelsensorpowercontrolcircuitsandotherconponents.Hostuserscontrolsystemorcontrolboardlightover-the-countertransactions,buttons,switchtounderstandandcontrolsystenoperation,BasedonthePIDcontrolmode,theoperatorinterfacesettingsinwaterpressure,PLCtopressuresettingsandmeasuredvalucsforthedeviationPIDoperationandregulationofdistributionthroughinverterpumpspeed,sothatwaterpressurewasmaintainedatthesetvalue.
2.Systenhanlwareconfiguration
ThesystemusesSiernensS7-200PLCanditsconfigurationsoftwareconstituteaconstantWinCCV6.0Waterpressurecontrolsystem,waterpressuremonitoringprocess.IndustroalEthernctcontrollerforPLCandtheoperatorstationcomputercommunicationbetwweentheRemoteI/OnetworkforthePLCandtheoperatorstationcompulercommunicationbetwweentheRemoteI/OnetworkforthePLCcontrollerandinverter,thesoftstarterofcommunicationbetwweenequipment.PLCcontrollermainlyusedtomonitorandcontrolwaterandelectricitysystems.For1#-4#pressurizedpumpconverterusingtheABBAcs510-01-031A4inverter,HMIoperatostationselectionDELLconputers,conputer,IndustrialEthernetservercardSiemensconmmunicationscompanyCP1612.
3.SoftwaredesignofSysten
ThecontrolsystemsoftwarecompanySiemensPCS7V5.2package.STEPV5.2PLCcontroller.HMImonitoringsystemusedWinCCV6.0version.HMIserverandoperatingstationareusingtheWindows2000operatingsystemtohaveanopenprogrammingenvironment.HeatingSationWinccconfigurationcontrolsoftwaremaiorconstantpressurewatersystemandcoalGalleryintwoparts.Implementionofthesystemofautomaticdetectionandautomaticcontrol.DetectionconstantpressurewaterandcoalGallcryequipmentoperationparameters.thereal-timedataacquisition.uploads.real-timedataacquisition.uploads,real-timedisplayandrecording.Ciontrolunitoperation.faultalarmandautomaticparkingoperation.Theconstantpressureofwatersupplypressuresystemconfigurationparameters.real-timemonitoringregulatorypressurepumpswaterpressureandsovalued.CoalHandingGalleryintocontrolthevolume.ofcoaltospeed,tomonitorthequalityofcoal(coalcrushingdegreeofqualityandimpurity)
4.PLC-BasedFuzzyConstantwatersupplysystemdesignconstantpressurewatersystemcomponents
1ConstantPressureWaterForm
Fromthewatersupplysystemprogrammablecontroller,inverter,pressuretransmiter,andtheconstactgrouponthepumpunitandothercomponents.ProgrammablecontrollerselectionofABControlLogixsystem.ItincludesLogix5550controller,analoginputmodules,digitalinputandoutputmodulesandcommunicationmodutes.Whichanaloginputmoduteusedtotestthewaterpressureontheexportsignal,digitalinputmoduleandvalvesKaistopped.InverselectionofAB1336PlusInverter.InverterandDevi2cenetcontrollerthtoughthenetworkforcommunication.
2.ConstantPressureWaterPrinciple
Theoutletchannelofpressuresensorinstallationwillexportwaterpressuresignalsareconvertedtoelectricalsignals,sendPLCfuzzyinferenceoperation,theoutputcontrolsignalstotheconverter,regulatingtheoperationofpumpmotorspeed,untiltheactualeliminationofhydraulicpressureandsetthedeviation,constantvoltagesupply.ProgrammablecontrollercancontrolpumpsKaistopped.Whenthesystemstartedworking,invertercontrolfromstarton1stpumpfrequencyoperation.Ifusersincreasedconsumptionoftheconverteroutputfrequencyupto50Hz,thepressurewillstillbelessthanthesetvalue,thenaftersometimedelay,onthe1stofthepumpswitchingfrequencyoperation;Inverterstartagainonthe2ndpumpoperation.Ifpressureislessthanthesetvalue,theywillbeonthe2ndtopumpswitchingfrequencyoperation;Inverterstartagainonthe3rdpumpoperationuntiltheoutputpressuresettingstoachievesofar.However,ifuserstoreducewaterconsumption,inaccordancewiththe“Kai-stop”principlewillbefollowedwithpumps.Thiscyclerepeatedlytoachieveconstantpressurewatersystem.
3.Fuzzy2PIcontrolalgorithm
Asthewatersupplysysteminmanyareas(suchasthepipenetworkandpumps)nonlinear,time-varying,andthevariablesstillexistbetweenthecross-coupling,soitisdifficulttoestablishaprecisemathematicalsystemmodel.ForsuchacomplicatedprocessthatmerelyusingtheconventionalPIDcontrolisdifficulttoachievethedesiredcontrol.Fuzzycontrolisnotdependentonthemathematicalmodelandtherightparameterssensitivetothemerits,Fuzzyusedtocontrolthewatersupplysystem,wecanimprovethecontrolsystemdynamicperformance.ButFuzzyControlSystemsteady-stateperformanceispoor,thisdesignofadual-modeFuzzy2PIcontrol,Asshowninfigure2,anditsdesignthinkingis;whenthepressureisgreatererrorwhenusingfuzzycontrol,toobtaingoodtransient;Whenthepressureonthestead-stateerrorintosmaller,switchedtoprocessfromPIcontrol,toobtaingoodsteadyprecision.PIcontrolalgorithmsandfuzzycontrolalgorithmsarePLC,switchingtimebyacomputerprogrambasedonpriortotheerrorautormatically.
Thesystemusestwo-inputsingle-outputfuzzycontroller.topressurethedesiredvalueandthemeasurementofeerrorandtheerrorasafuzzycontrollerinputlinguisticvariables,transducerfrequencyvariationulanguageasoutputvariables.Toeerror,theerrorrateecandcontrolvolumeufuzzysubsetof(NB,NS,ZE,PS,PB)andtheyquantifiedthedomainofsevengrades,(-3,-2,-1,0,1,2,3).Fuzzy