1、 外文文獻原稿和譯文原稿Thewatersupplysystemisthenationalproductionandlifeindispensableimportantoneannulus.Thetraditionalmethodofwatersupplyarea,waterpollution,infrastructureinvestment,butthemaindrawbackisthatwatercannotbekeptconstant,causingpartoftheequipmentcannotworknormally.Variablefrequencyspeedcontroltech

2、nologyisanewmatureACmotorsteplessspeedregulatingtechnology,itsuniqueexcellentcontrolperformanceiswidelyappliedtothespeedcontrolfield,especiallyinwatersupplyindustry.Duetothesafetyinproductionandthewaterqualityofspecialneeds,forconstantpressurewatersupplywiththestringentrequirements,sothefrequencycon

3、troltechnologyhasbeenmorein-depthapplication.Constantpressurewatersupplywaystoadvancedtechnology,constantpressure,convenientoperation,reliableoperation,energysaving,highdegreeofautomation,inpumpstationwatersupplycanperformthefollowingfunctions:tomaintainconstantpressure;thecontrolsystemcanbemanualor

4、automaticoperation;apluralityofpumpautomaticswitchoperation;systemofsleepandwake,whenpeoplestopwhenwater,thesystemisinasleepstate,untilthewaterdemandautomaticallywake;adjuststhePIDparametersonline;pumpunitandcircuitprotectiondetectionalarm,signaldisplay.Theactualpressureofthepipenetworkfeedbackandag

5、ivenpressurewerecompared,whenthepressureofapipenetworkislow,increasetheoutputoffrequencyconverter,pumpspeedfaster,watersupplyquantityincreases,forcingthepipenetworkpressurerise.Vicepumpspeedslowdown,reducethewatersupplypipenetworkpressuredrop,tokeeptheconstantpressurewatersupply.Systemhardwarestruct

6、ureSystemusesapressuresensor,PLCandinverterasacentralcontroldevice,toachieveadesiredfunction.Source:networktransmissionanddistributionequipmentinstallationinpipelinepressuresensor,fordetectingthewaterpressureofthepipenetwork,convertingpressureis420mAcurrentorvoltagesignalis010V,suppliedtotheinverter

7、.Converterpumpmotorcontroldevice,inaccordancewiththeconstantwaterpressureneedstobe050Hzfrequencysignalsupplypumpmotor,adjustitsspeedSAJconverterispowerful,i.e.pre-programmedsetparameterset,willusetherequiredintheprocessofsettingthenumberofparametersisreducedtoaminimum,defaultvalueaccordingtotheappli

8、cationparameterofthemacrochoiceanddifferent.ThesystemadoptsthePIDcontrolapplicationmacro,closedloopcontrol.Inverterbasedonaconstantpressurecorrespondingtothevoltagesettingvalueandfromthepressuresensortoobtainthefeedbackcurrentsignal,theuseofPIDcontrolmacroautomaticallyadjust,changethefrequencyoutput

9、valuetoadjustthecontrolthespeedofthepumpmotor,toensurethatthepipenetworkpressureconstantrequirements.PLCIntroductionPLC-ProgrammableLogicControllersarewidelyusedinrecentyearsthefieldofindustrialcontrolSuchasmetallurgy,steel,productionlines,etcItsmainfeatureisitsstableperformance,highcontrolprecision

10、andeasymaintenance.WithPCconnection,compiledintheproductionprocessaccordingtothecorrespondingprogramwillconvertdigitalsignalsintoanalogsignalinputcommandsoutputinstructionstocontroltheimplementationofcomponentstoachieveautomaticcontrolpurposes.Currently,themainaspectsofthemusicprogram-controlledfoun

11、tainimportedlightingconsoleanditsmatchingcontroldecoder,oncethefailureisnoteasytorepair,thepriceismoreexpensive.UsingPLCtechnology,youcanuseanordinaryPCtoreplaceimportedlightingcontrol,easymaintenance,lowcostPLCarticleonhowtousemusictechnologytoanalyzetheproblemofprogram-controlledfountain.Theapplic

12、ationofinverterintheconstantpressurewatersupplyThecharacteristicandanalysisofvariablefrequencyspeedregulationThewaterusersingeneralisdynamic,sothewatersupplyisinsufficientorexcesswatersupplysituationhasoccurred.Thewatersupplyandtheimbalancebetweentheconcentratedreflectioninwatersupplypressure,namely

13、waterandwatersupplyisless,thelowpressure;lesswaterconsumptionandwatersupply,thepressure.Keepthewaterpressureconstant,canmakethewatersupplyandwaterbalancebetweenwatersupplyandwaterforalongtime,thatis,lesswaterwhenthewaterisless,soastoimprovethequalityofwatersupply.Constantpressurewatersupplysystemfor

14、theuserisveryimportant.Inproductionandlivingwater,ifwatersupplyduetoinsufficientpressureorshortofwater,mayaffectthequalityoflife,seriouswhencaninfluencethesurvivalsafety,suchaswhenafireoccurs,ifthewaterpressureisinsufficientorwatersupply,canquicklyfire,maycausesignificanteconomiclossesandcasualties.

15、Therefore,waterareabymeansofArtsistheconstantpressurewatersupplysystem,canproducegreateconomicbenefitandsocialbenefit.Withthedevelopmentofelectricpowertechnology,frequencyconversiontechnologyperfected,withvariablefrequencyspeedcontrolasthecoreoftheintelligentwatercontrolsystemreplacedtheprevioushigh

16、levelwatertankandapressuretankandwatersupplyequipment,stablestarting,thestartingcurrentcanbelimitedwithinspecifiedcurrent,therebyavoidingthestartingtimeoftheimpactofpowergrid;becausetheaveragerotationalspeedofpumpisreduced,whichcanextendthepumpsandvalvesandotherthingsoflife;toeliminatethestartandsto

17、pofthewaterhammereffect.Thestableandsafeperformance,simpleandconvenientoperation,andcompleteandthoughtfulfunction,willmakethewatersupplyandwaterconservation,energysaving,laborsaving,ultimatelyachieveefficientoperation.TheapplicationofvariablefrequencycontrolconstantpressurewatersupplymodeUsuallyinth

18、esamewayinthewatersupplysystem,settingmultiplecommonpump,watersupplywhenthequantityofmultipumpfullopen,watersupplyononeortwohours.Inthevariablefrequencyspeedcontrolforconstantpressurewatersupply,intwoways,oneisallpumpswithafrequencyconverter;andeachwaterpumpwithafrequencyconverter.Afteramethodbasedo

19、npressurefeedbacksignal,operatedbyPIDautomaticallyadjuststheoutputfrequencyoftheinverter,changethespeedofthemotor,eventuallyreachingthepurposeofnetworkvoltage,aclosedloop,isrelativelysimple,butthecostishigh.Thepreviousmethodoflowcost,lessthankindofpoorperformance,butthecontrolprogramiscomplex,isthef

20、uturedirectionofdevelopment,suchastheShanghaiartsandscienceandtechnologyofconstantpressurewatersupplycontrolsystemcanrealizeainvertercontrolanynumberofmotorfunction.Theprinciplementionedbelowaremultiplemotorinverterdrivesystem.ThePIDcontrolprincipleAccordingtothefeedbackprinciple:tomaintainaphysical

21、quantityunchangedoressentiallyunchanged,itshouldbringthephysicalquantityandtheconstantcomparison,toformaclosedloopsystem.Wewanttokeepthepressureconstant,sowemustintroducethehydraulicfeedbackvaluewithagivenvalue,therebyformingaclosedloopsystem.Butthecontrolsystemischaracterizedbynonlinear,inertialsys

22、tem,nowthecontrolmethodcombinedwithPIDinthelargepressurefluctuation,usingfuzzycontrol,inordertoacceleratetheresponsespeedinthepressurerange;usingPIDtomaintainstaticaccuracy.ThisthroughthePLCandintelligentinstrumentcanshowthealgorithm,whilethePLCprogrammingtoshowwhenthepumpfrequencyandinverterswitchi

23、ngbetween.Practicehasprovedthat,usingthismethodisfeasible,andthecostisnothigh.Tomaintaintheconstantpressurewatersupplynetwork,accordingtothefeedbacktheoreminnetworkmanagementsysteminstalledonthepressuretransmitterasafeedbackelement,becauseoflong,largediameterpipesystemofwatersupply,pipelinepressurec

24、hargingareslower,sothesystemisabigtimelagsystem,isnoteasytodirectlywithPIDregulatorforcontrol,andadoptsPLCisinvolvedinthecontrolofthewaytoachievethecontrolsystemregulatestheeffect.FrequencycontrolUsingfrequencycontroltorealizeconstantpressurewatersupply,withadjustablevalvetorealizeconstantpressurewa

25、tersupply,energy-savingeffectisverysignificant(accordingtothespecificcircumstancescalculated).Theutilitymodelhastheadvantagesof:startingbalance,thestartingcurrentcanbelimitedwithinspecifiedcurrent,therebyavoidingthestartingtimeoftheimpactofpowergrid;becausetheaveragerotationalspeedofpumpisreduced,th

26、erebyprolongingtheservicelifeofpumpandvalveetc.;caneliminatethestartandstopofthewaterhammereffect;Generallyspeaking,whenperformedbyafrequencyconvertertocontrolamotor,justmaketheinvertermotorcapacityandtheactualcapacityofthemotorcanbe.Whenoneinvertercontroltwomotors,principleofinvertermotorcapacitysh

27、ouldbeequaltothecapacityofthetwomotors.Butifthepeakloadofwatermorethantwopumpsatfullsupplyalotofdifference,Shanghaiartsandscienceandtechnologyengineerssuggested,maybeconsideredappropriatetoreducethecapacityofthefrequencyconverter,butattentionshouldbepaidtoleaveenoughcapacity.Althoughthepumpatlowspee

28、d,smallworkingcurrentofthemotor.However,whentheuserwiththewatervolumechangesfrequently,themotorwillbeinfrequentascending,descendingandascending,descendingspeedstate,thecurrentspeedslightlyoverthemotorratedcurrent,causethemotoroverheat.Therefore,themotorthermalprotectionisrequired.Forthisduetofrequen

29、tascending,descendingspeedandaccumulatedtemperaturerise,frequencyconverterinelectronicthermalprotectionfunctionisdifficulttoplayaprotectiverole,soshouldbeusedinthermalrelayformotorthermalprotection.Themainfunctionofpreset,thehighestfrequencyshouldberatedmotorfrequencyconverterthehighestworkingfreque

30、ncy.Ascending,descendingspeedtimeinusingPIDregulatorcase,ascending,descendingvelocitytimeshouldbesettobeshort,soasnottoaffectthePIDadjusterdeterminesthedynamicresponseprocess.SuchasthefrequencyconverterwithPIDregulationfunction,aslongasthepresetsetPIDfunctioneffectively,thesettingoftheaccelerationan

31、ddecelerationtimewillautomaticallylapse.Constantpressurewatersupplysystempower:theoptimalenergy-savingcontrolsoftware,sothepumptoachievemaximumenergyefficiency;accordingtotheactualwateruse,watersavingsettingpressureofthepipenetwork,theautomaticcontrolpumpoutthewater,reducingthewaterrunning,leakageph

32、enomenon;reliableoperation:bythefrequencyconvertertorealizethesoftstartingofpump,thepumpisrealizedbyfrequencytothefrequencyofthebumplesstransfer,preventnetworkimpact,toavoidthepipenetworkpressuregauge,workfunction:thewholeChineseindustrialcontrolconfigurationsoftware,real-timemonitoringofeachsite,su

33、chasthemotorvoltage,current,frequency,pipenetworkpressureandflow.Andtheabilitytoaccumulateeachsiteelectricityuse,cumulativeperpumpoutthewater,atthesametimetoprovidevariousformsofprintstatements,inordertoanalyzethestatistical.flexiblecontrol:sectionwatersupply,watersupply,manuallyselectworkingmode.se

34、lfprotectionfunctions:suchasapumpfailure,taketheinitiativetothePCalarminformation,atthesametimestartstandbypump,inordertomaintainwaterbalance.Ifthecontrolsystemfailure,theusercandirectlyoperatemanualsystem,inordertoprotectthewatersupply.Thesystemapplicationwaterplant,pressurepumptheresidentslivingar

35、ea,hotelsandotherbuildingsenterpriseproductionwaterboilercirculatingwatersystemthefarmlandirrigationsystemComparedwithotherwatersupply,frequencyconstantpressurewatersupplysystem,inadditiontohavingsignificantenergy-savingeffectobviously,hasthefollowingadvantages:constantpressurewatersupplytechnologyb

36、yusingthefrequencyconvertertochangethemotorpowersupplyfrequency,andtoadjustthepumpspeedtochangethepumpoutletpressure,thanbyregulatingvalvecontrolpumpoutletpressure,hasareducedresistancegreatlyreducedtheeffectivenessoftheinterceptionloss.becauseofthevariablepumpworkinthefrequencycondition,atitsoutlet

37、flowrateislessthantheratedflowrate,pumpspeedisreduced,reducingtheabrasionofthebearingandfever,toextendthepumpandmotoroftheservicelifeofthemachine.pumpadoptssoftstartingmode,bysettingtheacceleratedaccelerationtime,avoidthemotorstartingcurrentimpact,onthegridvoltagefluctuationscausedbytheimpact,butals

38、otoavoidthesuddenaccelerationcausedbymotorpumpsystemssurge.Thecompleteeliminationofwaterhammer.torealizeautomaticcontrol,operatingpersonneldonotneedfrequentoperation,reduceslaborintensityofworkers,savesthemanpower.WorkingprincipleTransducerinthewatersysteminconjunctionwiththeintroductionofsmallPlcte

39、chnologynotonlychangethetraditionaluseofwatercontrolvalves,andinenergyconservation,Hengyacontrol,areverygoodresults,thepaperintroducedatransducer-PLCcontroltechnologyinthepumpcontrolapplications.ControlsystemusingoneTaiwantransducercanbringthreepumps,pumpscanworkatthefrequencypumpintheconventionalmo

40、delcanworkinthefrequencyconversionpumpmodel.Atthepumponlyinfrequencyconversionoroneoftheworkingfrequencymodethroughtworelaysefficientensureitssecurityandreliability.Systemstructureasfigure1shows,theuseofplacementinthelifeofwaterpressureBiansongqiwaterpressuresignaltransmissiontotheregulator,inaccord

41、ancewiththeregulatortosetthevalueandwarningoflowercomparedtosendsignalstothePlcandthetransducer,thesystemhasstoppedpumpingfromregulatorpressurelevelsignalsandtransducerfrequencyrangesignal,ifthelowpressure,regulatortothePlcapressurelowersignalPlcactivationtransducer,andafrequencyconversion1stpumpswo

42、rkstate,andtheoutputfrequencygraduallyincreasing,afteraperiodofadjustment,suchaspressureislow,then,Plcfor1stpumpsinthefrequencyofwork,2ndpumpfrequencyconversionworkatthestatepumps,suchaspressureislow,2pumpsatthefrequencyforthestateandmakethestate3rdpumpsinfrequencyconversionwork,andsoon.Whenthepress

43、ureregulatortolimitthepoliceonduty,regulatoroutputreduction,transducerfrequencyreducedtothelowfrequencyrangesetvalueatagivenfrequencytransducersignalstothelowerPLC,PLCAccordingtoKaiprinciplepausecontrolpumpoperationsequence,forexample,Plcreceivedlowerfrequencysignals,thesystempumpsstateisthefrequenc

44、y1st,2nd-frequency,3rdfrequencyconversion,thefirsttime1stpumpsactivated,thefirststop,thenasthepressurewashigh,thenstoppedonthe2ndpumps.Eachsystemisusedforslowstart,high-speedoperationinordertoenhanceoperationalefficiency.Constantpressurewatersupplyequipmentfrequencyconversioncontrolcabinetstructurea

45、ndprincipleVariablefrequencypumpcontrolsystemthroughthepipelinepressure,theinvertersystemwithbuilt-inPIDregulatoroperation,regulatetheoutputfrequency,andthentoachieveaconstantpressurewatersupplypipenetwork.Thefrequencyofthetransduceroverrunsignal(generallyusedaspipelinepressurelimitsignal)canbetimel

46、yinformedthePLCvariablefrequencypumpswitch.Inordertopreventtheoccurrenceofwaterhammer,pumpswitchislinkedtotheoutletvalve.Variablefrequencywaterpumpcontrolcabinetworksasfollows:Varioustypesofdirectlyfromthemunicipalpipenetworkwatertank(box).Suchas:theconstructionofvarioustypesofgroundwaterreservoirwa

47、ter,groundboilercoldwatersupplying,groundairconditioningsystemcoolingwatercirculatingpoolwater,groundwatercirculatingpoolwater,fireandsprayforgroundwaterreservoirinlet.Theintelligentvariablefrequencyconstantpressurewatersupplyenergy-savingcontrolcabinet,frequencyconversionwatersupplyenergy-savingcon

48、trolcabinetassumestheentiresystemiscomposedoffourpumps,aconverter,aPLCandaPIDandapressuretransmitterandapluralityofauxiliarycomponents.Thefunctionofeachpartareasfollows:installedinthewatersupplypipenetworkpressurepressuretransmitterwillbeconvertedinto1-5voltelectricalsignal;frequencyconversionspeedr

49、egulatorusedforadjustingthepumpspeedtoregulatetheflow;PLCforlogicswitching.Inaddition,thesystemisalsoequippedwithanauxiliarycircuit,inordertoensureautomaticcontrolsystemfailurecanberegulatedthroughtheartificialwaytomaintainthesystemoperation,toensurecontinuousproduction.frequencyconversioncontrolcab

50、inetfeatures:Accordingtotank(box)theheightofthewaterlevelintheautomaticcontrolelectromagneticvalve(orelectricvalve)openingandclosing,inordertocontrolthewatertank(pool)ofthewaterinletandthetank(box)toautomaticallymaintainacertainamountofwaterforusebytheuser.frequencyconversioncontrolcabinetselectioni

51、nstructionsofvariablefrequencywaterpumpcontrolcabinetismainlycomposedofvariablefrequencycontrolbox,apressuresensor,pumpetc.Frequencyconversioncontrolcabinetcomprisesacircuitbreaker,inverter,contactor,anintermediaterelay,PLCetc.VariablefrequencywaterpumpcontrolcabinetsystemselectingprinciplePumpheads

52、houldbegreaterthantheactualheight.Pumpflowsumshouldbegreaterthantheactualmaximumsupplyquantity.Selectionofvariablefrequencypumpcontrolcabinet:Accordingtotheuserswatersupplyandwaterheightdeterminationmodelofpumpandthenumber,thenthecontrolcabinetselection.Mayforesee:Thefuturefrequencyconversiontechnol

53、ogywillbeabletodeveloptothebelowdirection:(1)highperformanceThusincludinginternallevelingcircuit,thecontravariantelectriccircuitallusethehighfrequencyPWMelectriccircuittocausetheinput,theoutputallaresinewaves;Usesthemulti-densificationregardingthelargecapacityfrequencychangerandmanymachineisparallel

54、;Reducesfrequencychangerownloss,therealizationhighefficiency;Realizesautotuneorfromtheoptimization,theremotecontrolandcontrolsfar;Evenmorefacestheuser,furtherenhancestheworkabilityandMaintainability:Turnstowards,thefeatherweightdevelopmentsmall,aswellasreducesthecostandsoon.(2)IntellectualizationInc

55、ludingtwoaspects:Reducesthehardwareasfaraspossible,realizesthehardwaresoftware;Usestheintelligentelectricpowerelectronicdeviceandotherintellectualizedpart.Theintegrationistheintellectualizedfoundation.entiredigitizationInrecentyears,eachkindofmoderncontroltheory,theexpertsystem,thefuzzycontrolandthe

56、neuroncontrolandsoonallwerethedevelopmenthotspots,willcausetheelectricpowerelectroniccontroltechnologicaldevelopmenttoabrand-newstage.Estimatedthe21stcenturyentirenumericalcontroltheapplicationwillbemorewidespreadthoroughly,evenwillsubstituteforthesimulationcontrol.SystematizationFrequencyconversion

57、technologydevelopmentisinseparablefromthedevelopmentofrelatedtechnologies,frequencyconversiontechnologydevelopmentinthe21stcenturyistogrid,regulators,relymachine,electricmotors,productionmachineryandcontrolsystemsasawhole,fromthesystemforconsideration.ConclusionAhighqualityvariablefrequencycontrolbo

58、x,fromthedesign,technology,manufacturing,transportation,packaging,istheactualproductsrequireahigherrequest,allaspectsofqualityassurance,canmakethehighqualityandthelevelofcontrolcabinet.Constantpressurewatersupplyusedinthefieldofwatersupply,communitylivingandfirewatersupplysystem,andcanalsobeusedforh

59、otwatersupply,constantpressuresprinklersystem.industrialbusinesslife,productionwatersupplysystemandtheotherfactoryneedsconstantvoltagecontrolareas(suchasaircompressorsystemofconstantpressuregassupply,constantpressureairsupply).Onvariousoccasions,theconstantpressurecontrol,coolingwaterandcirculatingw

60、atersupplysystem.sewagepumpingstations,sewagetreatmentandsewageliftingsystem.agriculturalirrigation,gardensprinkler,waterscapeandmusicfountainsystem.hotels,largepublicbuildingwaterandfiresystem.供水系統是國民生產生活中不可缺少的重要一環。傳統供水方式占地面積大，水質易污染，基建投資多，而最主要的缺點是水壓不能保持恒定，導致部分設備不能正常工作。變頻調速技術是一種新型成熟的交流電機無極調速技術，它以其獨特