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1、ElevatorSystemBasedonPLCComposedbytheorderofrelaycontrolsystemisarealizationofthefirstelevatorcontrolmethod.However,toenterthenineties,withthedevelopmentofscienceandtechnologyandthewidespreadapplicationofcomputertechnology,thesafetyofelevators,reliabilityoftheincreasinglyhighdemandontherelaycontrolw

2、eaknessesarebecomingevident.Elevatorcontrolsystemrelaysthefailureratehigh,greatlyreducesthereliabilityandsafetyofelevators,andescalatorsstoppedoftentotakewiththestaffabouttheinconvenienceandfear.Andtheeventratherthantakingtheliftorsquatattheendoftheliftwillnotonlycausedamagetomechanicalcomponents,bu

3、talsopersonalaccidentmayoccur.ProgrammableLogicController(PLC)isthefirstorderlogiccontrolinaccordancewiththeneedsofdevelopedspecificallyforindustrialenvironmentapplicationstooperatetheelectronicdigitalcomputingdevice.Givenitsadvantages,atpresent,therelaycontrolthelifthasbeengraduallyreplacedbyPLCcon

4、trol.Atthesametime,ACvariablefrequencymotorspeedcontroltechnology,thewaytheliftdragspeedhasbeenagradualtransitionfromDCtoACfrequencyconverter.Thus,PLCcontroltechnologyincreasesVVVFElevatormoderntechnologyhasbecomeahotindustry.1.PLCelevatorcontroladvantages(1)usedinelevatorcontrolPLC,withsoftwarefora

5、utomaticcontrolofliftoperation,reliabilitygreatlyincreased.(2)layerwasremovedandamajorityoftherelay,thecontrolsystemstructureissimple,tosimplifytheexternalcircuit.(3)PLCcanbeavarietyofcomplexcontrolsystem,easytoaddorchangecontrolfunctions.(4)PLCcanbeautomatedfaultdetectionandalarmdisplaytoimprovethe

6、operationofsecurityandeaseofmaintenance.(5)forthegroupcontroltheallocationandmanagement,andimprovetheefficiencyofelevatoroperation.(6)donotneedtochangethecontrolschemechangeswhenthehardwareconnection.2.VVVFelevatorcontrolcharacteristicsWiththepowerelectronics,microelectronicsandcomputertechnologytoc

7、ontroltherapiddevelopmentoftechnology,communicationtechnologyVVVFalsoaveryrapidrate.ACvariablefrequencymotorspeedcontroltechnologyisthepowertoimprovetheprocessinordertoimproveproductqualityandimprovingtheenvironmentandpromotingtechnologicalprogressasaprimarymeans.Frequencyofitsexcellentperformancean

8、dthespeedbrakefromasmoothperformance,highefficiency,highpowerfactorandpower-savingeffectofabroadscopeofapplicationandmanyotheradvantagesofbeingathomeandabroadrecognizedasthemostpromisingapproachspeedExchangecharacteristicsofVVVFElevator(1)lowenergyconsumption(2)lowloadcircuit,therequiredemergencypow

9、ersupplydeviceofsmallIntheaccelerationstage,therequiredstart-upcurrentoflessthan2.5timestheratedcurrent.Peakstartingcurrentandtimeisshort.Sincethestartingcurrentisdrasticallyreduced,sopowerconsumptionandpowersupplycablediametercanbereducedalot.Requiredforemergencypowersupplydevicesarealsorelativelys

10、mallsize.(3)highreliabilityandlongservicelife.(4)goodcomfortElevatoroperationisbesttofollowthespeedcurveofagivenoperation.Theircharacteristicscanbeadaptedtohumanfeelings,andtoensurethatnoiseoperation,smoothbrakePinglayerandhighprecision(5)Stablenoise-free(6)Inthecar,theengineroomandadjacentareastoen

11、surethatnoise.Becausetheirsystemsuseahighclockfrequency.Alwaysproduceatruesinewavepowersupplycurrentyet.Motortorquerippledoesnotappear.Therefore,toeliminatevibrationandnoise.3.ElevatorcontroltechnologyTheso-calledelevatorcontroltechnologyreferstotheelevatordrivesystemandelectricalcontrolsystemofauto

12、maticcontrol.70asthe20thcenturyinChinaselevatorwasmarkedbytheexchangeoftwo-speedelevator.Itsspeedisusedtochangetheelevatortractionmotoroftheveryfew,twoormulti-levelapproachtothenumberofwindings,veryfewofthemashigh-speedwindingofthewinding,averyfewnumberofwindingsasthelow-speedwinding.Windingsforhigh

13、-speedelevator-speedstart-upandrunning,low-speedwindingsforbrakingandthemaintenanceofelevators.Theearly80s,VVVFinvertercontrolledvariableliftsystemavailable.ItusesACmotordrives,areabletoreachthelevelofDCmotor,controlthespeedofthecurrenthasreached6m/sec.Itssmallsize,lightweight,highefficiency,energys

14、aving,includingthepastalmostalltheadvantagesofthelift.Isthelatestelevatordrivesystem.Operationinverticallift,thereisalsothestartingpointoftheterminusstation.Formorethanthree-storyelevatorbuildings,thestartingpointoftheterminalstationsandstopsbetweenthehadnot,thestartingpointforthesestationsatthefirs

15、tflooroftheterminallocatedatthehighestfloor.Startingpointinthefirstfloorofthestationknownasbasestations,knownasthestartingpointatbothendsoftheterminalstationsandstationsatbothendsofintermediatestopsbetweenstations.Outsidethestationhasacallbox,boxsetareusedbystaffforelevatorcallbuttonortouchthecallbu

16、tton,thegeneralendsoftheliftstationsinthecallboxontheSettingsbuttonortouchofabutton.Middlelayerofthestationsetupthecallboxbuttonortouchbutton2.Nodriversforthecontrolofelevators,atvariousstationsaresetupcallsmeonabuttonortouchbutton.Elevatorcarandtheinternalsettings(exceptfordebriselevator)tomanipula

17、teme.Controlboxswitchonthehandleorsetupstationsandthecorrespondinglayerofbuttonsortouch-buttoncontrolboxonthetouch-controlbuttonorcommandbuttonortouchthecitybutton.Outsidethecommandbuttonortouch-buttonissueasthesignaloutsidethecommandsignal,withinthecommandbuttonortouch-buttonissuewithinthesignalasa

18、commandsignal.80Inthemid-20thcentury,thetouchbuttonhasbeenreplacedbymicro-button.Astheelevatorcallboxoutsidethebasestation,inadditiontosetupacallbuttonortouchbutton,butalsosetakeyswitchinordertoworktheelevatorclearance.Driversormanagementstafftoopentheelevatortothebasestationcanwrigglethroughadedica

19、tedkeytothekeyswitch.Closetheelevatorinplacetoautomaticallycutofftheelevatorcontrolpowersupplyorpowersupply.4.PLCControlElevatorDesignWiththecontinuousdevelopmentofurbanconstruction,theincreasinghigh-risebuildings,elevatorsandlifeinthenationaleconomyhasabroadapplication.Elevatorhigh-risebuildingsasa

20、meansoftransportintheverticalrunofdailylifehasbeeninextricablylinkedwithpeople.Infacttheliftisbasedonexternalcallcontrolsignals,aswellasthelawsoftheirown,suchasrunning,andthecallisrandom,theliftisactuallyaman-machineinteractivecontrolsystem,simpletousecontrolorlogiccontrolordercannotmeetthecontrolre

21、quirements,andtherefore,elevatorcontrolsystemusesarandomcontrollogic.Elevatorcontroliscurrentlygenerallyusedintwoways,first,theuseofcomputerasasignalcontrolunit,thecompletionoftheliftsignalacquisition,operationandfunctionoftheset,toachievetheliftandsettheautomaticschedulingfunctiontoruntheelection,d

22、ragthecontrolfrominvertertocomplete；thesecondcontrolmodewithprogrammablelogiccontroller(PLC)toreplacethecomputercontrolsignalsetstheelection.Fromthecontrolandperformance,thesetwotypesofmethodsandthereisnosignificantdifference.Mostofthedomesticmanufacturerstochoosethesecondapproach,becausethesmallers

23、caleofproduction,theirdesignandmanufactureofhighcostofcomputercontroldevices；andPLChighreliability,convenientandflexibleprogramdesign,anti-interferenceability,stableandreliableoperationofthecharacteristicsofTherefore,theelevatorcontrolsystemisnowwidelyusedtorealizeprogrammablecontroller.5.Elevatorco

24、ntrolsystemcharacteristicsOperationoftheliftcurveisabovethestarttoruncomfortindicatorsliftthekeyfeatures,andcomfortaredirectlyrelatedwiththeacceleration,accordingtocontroltheory,foracertainamountofchangeaccordingtothelawmustbedirectlycontrolled,forelevatorcontrolsystem,accordingtotheidealacceleratio

25、ncurveaccelerationfeedbacktobeused,inaccordancewiththemotortorqueequation:M-MZ=M=J(dn/dt),canbeseenreflectedintherateofchangeofaccelerationofthesystemofdynamictorquechangesonthecontrolsystemtocontroltheaccelerationofthedynamictorqueM=M-MZ.Therefore,duringthistimetocontroltheuseoftheprincipleofaccele

26、ration,whenthestartrateofincreaseinsteady-statevalueabove90%,theaccelerationcontrolsystembytheswitchtospeedcontrol,asinparagraphsteadyspeed,speedcontrolfortheconstantfluctuationsinthesmaller,littlechangeinacceleration,speedandtheuseofclosed-loopcontrolcanmaintainasteady-statespeedaccuracyandprecisionforthebrakingsectiontocreatetheconditionspinglayer.Isrisingatarateinthesystem,andalthoughtheabove-speedPIregulatorusedtocontrol,buttwoofthePIparametersaredifferentinordertoimprovethesystemdynamicresponseindicators.Thebrakeinthesystem,