PLC-Based Monitoring Control System for Induction

外文翻译（原文）1DesignandImplementationofPLC-BasedMonitoringControlSystemforInductionMotorAbstract：Theimplementationofamonitoringandcontrolsystemfortheinductionmotorbasedonprogrammablelogiccontroller(PLC)technologyisdescribed.Also,theimplementationofthehardwareandsoftwareforspeedcontrolandprotectionwiththeresultsobtainedfromtestsoninductionmotorperformanceisprovided.ThePLCcorrelatestheoperationalparameterstothespeedrequestedbytheuserandmonitorsthesystemduringnormaloperationandundertripconditions.TestsoftheinductionmotorsystemdrivenbyinverterandcontrolledbyPLCproveahigheraccuracyinspeedregulationascomparedtoaconventionalcontrolsystem.TheefficiencyofPLCcontrolisincreasedathighspeedsupto95%ofthesynchronousspeed.Thus,PLCprovesthemselvesasaveryversatileandeffectivetoolinindustrialcontrolofelectricdrives.Keywords：Computer-controlledsystems,computerizedmonitoring,electricdrives,inductionmotors,motioncontrol,programmablelogiccontrollers(PLCs),variable-frequencydrives,voltagecontrol.I.INTRODUCTIONSincetechnologyformotioncontrolofelectricdrivesbecameavailable,theuseofprogrammablelogiccontrollers(PLCs)withpowerelectronicsinelectricmachinesapplicationshasbeenintroducedinthemanufacturingautomation[1],[2].Thisuseoffersadvantagessuchaslowervoltagedropwhenturnedonandtheabilitytocontrolmotorsandotherequipmentwithavirtuallyunitypowerfactor[3].ManyfactoriesusePLCsinautomationprocessestodiminishproductioncostandtoincreasequalityandreliability[4]–[9].Otherapplicationsincludemachinetoolswithimprovedprecisioncomputerizednumericalcontrol(CNC)duetotheuseofPLCs[10].Toobtainaccurateindustrialelectricdrivesystems,itisnecessarytousePLCsinterfacedwithpowerconverters,personalcomputers,andotherelectricequipment外文翻译（原文）2[11]–[13].Nevertheless,thismakestheequipmentmoresophisticated,complex,andexpensive[14],[15].FewpaperswerepublishedconcerningdcmachinescontrolledbyPLCs.Theyreportboththeimplementationofthefuzzymethodforspeedcontrolofadcmotor/generatorsetusingaPLCtochangethearmaturevoltage[16],andtheincorporationofanadaptivecontrollerbasedontheself-tuningregulatortechnologyintoanexistingindustrialPLC[17].Also,othertypesofmachineswereinterfacedwithPLCs.Thereby,anindustrialPLCwasusedforcontrollingsteppermotorsinafive-axisrotorposition,directionandspeed,reducingthenumberofcircuitcomponents,loweringthecost,andenhancingreliability[18].Forswitchedreluctancemotorsasapossiblealternativetoadjustablespeedacanddcdrives,asinglechiplogiccontrollerforcontrollingtorqueandspeedusesaPLCtoimplementthedigitallogiccoupledwithapowercontroller[19].OtherreportedapplicationconcernsalinearinductionmotorforpassengerelevatorswithaPLCachievingthecontrolofthedrivesystemandthedataacquisition[20].Tomonitorpowerqualityandidentifythedisturbancesthatdisruptproductionofanelectricplant,twoPLCswereusedtodeterminethesensitivityoftheequipment[21].OnlyfewpaperswerepublishedinthefieldofinductionmotorswithPLCs.Apowerfactorcontrollerforathree-phaseinductionmotorutilizesPLCtoimprovethepowerfactorandtokeepitsvoltagetofrequencyratioconstantunderthewholecontrolconditions[3].Thevectorcontrolintegratedcircuitusesacomplexprogrammablelogicdevice(CPLD)andintegerarithmeticforthevoltageorcurrentregulationofthree-phasepulse-widthmodulation(PWM)inverters[22].Manyapplicationsofinductionmotorsrequirebesidesthemotorcontrolfunctionality,thehandlingofseveralspecificanaloganddigitalI/Osignals,homesignals,tripsignals,on/off/reversecommands.Insuchcases,acontrolunitinvolvingaPLCmustbeaddedtothesystemstructure.ThispaperpresentsaPLC-basedmonitoringandcontrolsystemforathree-phaseinductionmotor.Itdescribesthe外文翻译（原文）3designandimplementationoftheconfiguredhardwareandsoftware.Thetestresultsobtainedoninductionmotorperformanceshowimprovedefficiencyandincreasedaccuracyinvariable-loadconstant-speed-controlledoperation.Thus,thePLCcorrelatesandcontrolstheoperationalparameterstothespeedsetpointrequestedbytheuserandmonitorstheinductionmotorsystemduringnormaloperationandundertripconditions.II.PLCASSYSTEMCONTROLLERAPLCisamicroprocessor-basedcontrolsystem,designedforautomationprocessesinindustrialenvironments.Itusesaprogrammablememoryfortheinternalstorageofuser-orientatedinstructionsforimplementingspecificfunctionssuchasarithmetic,counting,logic,sequencing,andtiming[23],[24].APLCcanbeprogrammedtosense,activate,andcontrolindustrialequipmentand,therefore,incorporatesanumberofI/Opoints,whichallowelectricalsignalstobeinterfaced.InputdevicesandoutputdevicesoftheprocessareconnectedtothePLCandthecontrolprogramisenteredintothePLCmemory(Fig.1).Fig.1.ControlactionofaPLC.Inourapplication,itcontrolsthroughanaloganddigitalinputsandoutputsthevaryingload-constantspeedoperationofaninductionmotor.Also,thePLCcontinuouslymonitorstheinputsandactivatestheoutputsaccordingtothecontrolprogram.ThisPLCsystemisofmodulartypecomposedofspecifichardware外文翻译（原文）4buildingblocks(modules),whichplugdirectlyintoaproprietarybus:acentralprocessorunit(CPU),apowersupplyunit,input-outputmodulesI/O,andaprogramterminal.Suchamodularapproachhastheadvantagethattheinitialconfi