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1、外文资料翻译ElevatorSystemBasedonPLCComposedbytheorderofrelaycontrolsystemisarealizationofthefirstelevatorcontrolmethod.However,toenterthenineties,withthedevelopmentofscienceandtechnologyandthewidespreadapplicationofcomputertechnology,thesafetyofelevators,reliabilityoftheincreasi
2、nglyhighdemandontherelaycontrolweaknessesarebecomingevident. Elevatorcontrolsystemrelaysthefailureratehigh,greatlyreducesthereliabilityandsafetyofelevators,andescalatorsstoppedoftentotakewiththestaffabouttheinconvenienceandfear.Andtheeventratherthantakingtheliftorsquatatth
3、eendoftheliftwillnotonlycausedamagetomechanicalcomponents,butalsopersonalaccidentmayoccur.ProgrammableLogicController(PLC)isthefirstorderlogiccontrolinaccordancewiththeneedsofdevelopedspecificallyforindustrialenvironmentapplicationstooperatetheelectronicdigitalcomputingdevi
4、ce.Givenitsadvantages,atpresent,therelaycontrolthelifthasbeengraduallyreplacedbyPLCcontrol.Atthesametime,ACvariablefrequencymotorspeedcontroltechnology,thewaytheliftdragspeedhasbeenagradualtransitionfromDCtoACfrequencyconverter.Thus,PLCcontroltechnologyincreasesVVVFElevator
5、moderntechnologyhasbecomeahotindustry.1.PLCelevatorcontroladvantages(1)usedinelevatorcontrolPLC,withsoftwareforautomaticcontrolofliftoperation,reliabilitygreatlyincreased. (2)layerwasremovedandamajorityoftherelay,thecontrolsystemstructureissimple,tosimplifytheexternalcircui
6、t. (3)PLCcanbeavarietyofcomplexcontrolsystem,easytoaddorchangecontrolfunctions. (4)PLCcanbeautomatedfaultdetectionandalarmdisplaytoimprovetheoperationofsecurityandeaseofmaintenance. (5)forthegroupcontroltheallocationandmanagement,andimprovetheefficiencyofelevatoroperation.(
7、6)donotneedtochangethecontrolschemechangeswhenthehardwareconnection.2.VVVFelevatorcontrolcharacteristicsWiththepowerelectronics,microelectronicsandcomputertechnologytocontroltherapiddevelopmentoftechnology,communicationtechnologyVVVFalsoaveryrapidrate.ACvariablefrequencymot
8、orspeedcontroltechnologyisthepowertoimprovetheprocessinordertoimproveproductqualit
