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ElevatorSystemBasedonPLCComposedbytheorderofrelaycontrolsystemisarealizationofthefirstelevatorcontrolmethod.However,toenterthenineties,withthedevelopmentofscienceandtechnologyandthewidespreadapplicationofcomputertechnology,thesafetyofelevators,reliabilityoftheincreasinglyhighdemandontherelaycontrolweaknessesarebecomingevident.Elevatorcontrolsystemrelaysthefailureratehigh,greatlyreducesthereliabilityandsafetyofelevators,andescalatorsstoppedoftentotakewiththestaffabouttheinconvenienceandfear.Andtheeventratherthantakingtheliftorsquatattheendoftheliftwillnotonlycausedamagetomechanicalcomponents,butalsopersonalaccidentmayoccur.ProgrammableLogicController(PLC)isthefirstorderlogiccontrolinaccordancewiththeneedsofdevelopedspecificallyforindustrialenvironmentapplicationstooperatetheelectronicdigitalcomputingdevice.Givenitsadvantages,atpresent,therelaycontrolthelifthasbeengraduallyreplacedbyPLCcontrol.Atthesametime,ACvariablefrequencymotorspeedcontroltechnology,thewaytheliftdragspeedhasbeenagradualtransitionfromDCtoACfrequencyconverter.Thus,PLCcontroltechnologyincreasesVVVFElevatormoderntechnologyhasbecomeahotindustry.1.PLCelevatorcontroladvantages(1)usedinelevatorcontrolPLC,withsoftwareforautomaticcontrolofliftoperation,reliabilitygreatlyincreased.(2)layerwasremovedandamajorityoftherelay,thecontrolsystemstructureissimple,tosimplifytheexternalcircuit.(3)PLCcanbeavarietyofcomplexcontrolsystem,easytoaddorchangecontrolfunctions.(4)PLCcanbeautomatedfaultdetectionandalarmdisplaytoimprovetheoperationofsecurityandeaseofmaintenance.(5)forthegroupcontroltheallocationandmanagement,andimprovetheefficiencyofelevatoroperation.(6)donotneedtochangethecontrolschemechangeswhenthehardwareconnection.2.VVVFelevatorcontrolcharacteristicsWiththepowerelectronics,microelectronicsandcomputertechnologytocontroltherapiddevelopmentoftechnology,communicationtechnologyVVVFalsoaveryrapidrate.ACvariablefrequencymotorspeedcontroltechnologyisthepowertoimprovetheprocessinordertoimproveproductqualityandimprovingtheenvironmentandpromotingtechnologicalprogressasaprimarymeans.Frequencyofitsexcellentperformanceandthespeedbrakefromasmoothperformance,highefficiency,highpowerfactorandpower-savingeffectofabroadscopeofapplicationandmanyotheradvantagesofbeingathomeandabroadrecognizedasthemostpromisingapproachspeedExchangecharacteristicsofVVVFElevator(1)lowenergyconsumption(2)lowloadcircuit,therequiredemergencypowersupplydeviceofsmallIntheaccelerationstage,therequiredstart-upcurrentoflessthan2.5timestheratedcurrent.Peakstartingcurrentandtimeisshort.Sincethestartingcurrentisdrasticallyreduced,sopowerconsumptionandpowersupplycablediametercanbereducedalot.Requiredforemergencypowersupplydevicesarealsorelativelysmallsize.(3)highreliabilityandlongservicelife.(4)goodcomfortElevatoroperationisbesttofollowthespeedcurveofagivenoperation.Theircharacteristicscanbeadaptedtohumanfeelings,andtoensurethatnoiseoperation,smoothbrakePinglayerandhighprecision(5)Stablenoise-free(6)Inthecar,theengineroomandadjacentareastoensurethatnoise.Becausetheirsystemsuseahighclockfrequency.Alwaysproduceatruesinewavepowersupplycurrentyet.Motortorquerippledoesnotappear.Therefore,toeliminatevibrationandnoise.3.ElevatorcontroltechnologyTheso-calledelevatorcontroltechnologyreferstotheelevatordrivesystemandelectricalcontrolsystemofautomaticcontrol.70asthe20thcenturyinChinaselevatorwasmarkedbytheexchangeoftwo-speedelevator.Itsspeedisusedtochangetheelevatortractionmotoroftheveryfew,twoormulti-levelapproachtothenumberofwindings,veryfewofthemashigh-speedwindingofthewinding,averyfewnumberofwindingsasthelow-speedwinding.Windingsforhigh-speedelevator-speedstart-upandrunning,low-speedwindingsforbrakingandthemaintenanceofelevators.Theearly80s,VVVFinvertercontrolledvariableliftsystemavailable.ItusesACmotordrives,areabletoreachthelevelofDCmotor,controlthespeedofthecurrenthasreached6m/sec.Itssmallsize,lightweight,highefficiency,energysaving,includingthepastalmostalltheadvantagesofthelift.Isthelatestelevatordrivesystem.Operationinverticallift,thereisalsothestartingpointoftheterminusstation.Formorethanthree-storyelevatorbuildings,thestartingpointoftheterminalstationsandstopsbetweenthehadnot,thestartingpointforthesestationsatthefirstflooroftheterminallocatedatthehighestfloor.Startingpointinthefirstfloorofthestationknownasbasestations,knownasthestartingpointatbothendsoftheterminalstationsandstationsatbothendsofintermediatestopsbetweenstations.Outsidethestationhasacallbox,boxsetareusedbystaffforelevatorcallbuttonortouchthecallbutton,thegeneralendsoftheliftstationsinthecallboxontheSettingsbuttonortouchofabutton.Middlelayerofthestationsetupthecallboxbuttonortouchbutton2.Nodriversforthecontrolofelevators,atvariousstationsaresetupcallsmeonabuttonortouchbutton.Elevatorcarandtheinternalsettings(exceptfordebriselevator)tomanipulateme.Controlboxswitchonthehandleorsetupstationsandthecorrespondinglayerofbuttonsortouch-buttoncontrolboxonthetouch-controlbuttonorcommandbuttonortouchthecitybutton.Outsidethecommandbuttonortouch-buttonissueasthesignaloutsidethecommandsignal,withinthecommandbuttonortouch-buttonissuewithinthesignalasacommandsignal.80Inthemid-20thcentury,thetouchbuttonhasbeenreplacedbymicro-button.Astheelevatorcallboxoutsidethebasestation,inadditiontosetupacallbuttonortouchbutton,butalsosetakeyswitchinordertoworktheelevatorclearance.Driversormanagementstafftoopentheelevatortothebasestationcanwrigglethroughadedicatedkeytothekeyswitch.Closetheelevatorinplacetoautomaticallycutofftheelevatorcontrolpowersupplyorpowersupply.4.PLCControlElevatorDesignWiththecontinuousdevelopmentofurbanconstruction,theincreasinghigh-risebuildings,elevatorsandlifeinthenationaleconomyhasabroadapplication.Elevatorhigh-risebuildingsasameansoftransportintheverticalrunofdailylifehasbeeninextricablylinkedwithpeople.Infacttheliftisbasedonexternalcallcontrolsignals,aswellasthelawsoftheirown,suchasrunning,andthecallisrandom,theliftisactuallyaman-machineinteractivecontrolsystem,simpletousecontrolorlogiccontrolordercannotmeetthecontrolrequirements,andtherefore,elevatorcontrolsystemusesarandomcontrollogic.Elevatorcontroliscurrentlygenerallyusedintwoways,first,theuseofcomputerasasignalcontrolunit,thecompletionoftheliftsignalacquisition,operationandfunctionoftheset,toachievetheliftandsettheautomaticschedulingfunctiontoruntheelection,dragthecontrolfrominvertertocomplete；thesecondcontrolmodewithprogrammablelogiccontroller(PLC)toreplacethecomputercontrolsignalsetstheelection.Fromthecontrolandperformance,thesetwotypesofmethodsandthereisnosignificantdifference.Mostofthedomesticmanufacturerstochoosethesecondapproach,becausethesmallerscaleofproduction,theirdesignandmanufactureofhighcostofcomputercontroldevices；andPLChighreliability,convenientandflexibleprogramdesign,anti-interferenceability,stableandreliableoperationofthecharacteristicsofTherefore,theelevatorcontrolsystemisnowwidelyusedtorealizeprogrammablecontroller.5.ElevatorcontrolsystemcharacteristicsOperationoftheliftcurveisabovethestarttoruncomfortindicatorsliftthekeyfeatures,andcomfortaredirectlyrelatedwiththeacceleration,accordingtocontroltheory,foracertainamountofchangeaccordingtothelawmustbedirectlycontrolled,forelevatorcontrolsystem,accordingtotheidealaccelerationcurveaccelerationfeedbacktobeused,inaccordancewiththemotortorqueequation:M-MZ=M=J(dn/dt),canbeseenreflectedintherateofchangeofaccelerationofthesystemofdynamictorquechangesonthecontrolsystemtocontroltheaccelerationofthedynamictorqueM=M-MZ.Therefore,duringthistimetocontroltheuseoftheprincipleofacceleration,whenthestartrateofincreaseinsteady-statevalueabove90%,theaccelerationcontrolsystembytheswitchtospeedcontrol,asinparagraphsteadyspeed,speedcontrolfortheconstantfluctuationsinthesmaller,littlechangeinacceleration,speedandtheuseofclosed-loopcontrolcanmaintainasteady-statespeedaccuracyandprecisionforthebrakingsectiontocreatetheconditionspinglayer.Isrisingatarateinthesystem,andalthoughtheabove-speedPIregulatorusedtocontrol,buttwoofthePIparametersaredifferentinordertoimprovethesystemdynamicresponseindicators.Thebrakeinthesystem,
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