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1、外文资料翻译ElevatorSystemBasedonPLCComposedbytheorderofrelaycontrolsystemisarealizationofthefirstelevatorcontrolmethod.However,toenterthenineties,withthedevelopmentofscienceandtechnologyandthewidespreadapplicationofcomputertechnology,thesafetyofelevators,reliabilityoftheincreasinglyhighdema
2、ndontherelaycontrolweaknessesarebecomingevident. Elevatorcontrolsystemrelaysthefailureratehigh,greatlyreducesthereliabilityandsafetyofelevators,andescalatorsstoppedoftentotakewiththestaffabouttheinconvenienceandfear.Andtheeventratherthantakingtheliftorsquatattheendoftheliftwillnotonly
3、causedamagetomechanicalcomponents,butalsopersonalaccidentmayoccur.ProgrammableLogicController(PLC)isthefirstorderlogiccontrolinaccordancewiththeneedsofdevelopedspecificallyforindustrialenvironmentapplicationstooperatetheelectronicdigitalcomputingdevice.Givenitsadvantages,atpresent,ther
4、elaycontrolthelifthasbeengraduallyreplacedbyPLCcontrol.Atthesametime,ACvariablefrequencymotorspeedcontroltechnology,thewaytheliftdragspeedhasbeenagradualtransitionfromDCtoACfrequencyconverter.Thus,PLCcontroltechnologyincreasesVVVFElevatormoderntechnologyhasbecomeahotindustry.1.PLCeleva
5、torcontroladvantages(1)usedinelevatorcontrolPLC,withsoftwareforautomaticcontrolofliftoperation,reliabilitygreatlyincreased. (2)layerwasremovedandamajorityoftherelay,thecontrolsystemstructureissimple,tosimplifytheexternalcircuit. (3)PLCcanbeavarietyofcomplexcontrolsystem,easytoaddorchan
6、gecontrolfunctions. (4)PLCcanbeautomatedfaultdetectionandalarmdisplaytoimprovetheoperationofsecurityandeaseofmaintenance. (5)forthegroupcontroltheallocationandmanagement,andimprovetheefficiencyofelevatoroperation.(6)donotneedtochangethecontrolschemechangeswhenthehardwareconnection.2.VV
7、VFelevatorcontrolcharacteristicsWiththepowerelectronics,microelectronicsandcomputertechnologytocontroltherapiddevelopmentoftechnology,communicationtechnologyVVVFalsoaveryrapidrate.ACvariablefrequencymotorspeedcontroltechnologyisthepowertoimprovetheprocessinordertoimproveproductqualit