电子信息工程 外文翻译 外文文献 英文文献 文献翻译Word下载.docx

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DcenterofintelligentcontrollerofpumpandvalveandbuiltupmassproductionR&

Dbasis,cooperatingwithShanghaiJiaotongUniversityandShanghaiUniversity;

constructedFCSremotediagnosisandservicecenterofintelligentcontrollerofpumpandvalve;

constructedFCStrainingcenterofintelligentcontrollerofpumpandvalve;

foundedmassproductionR&

DbasisalongwiththeRockwellLaboratoryofShanghaiJiaotongUniversityandCIMSCenter.

1Summary

（1）Fieldbuscontrolsystemisasystemappliedtofieldofproductionandmicrocomputerizedmeasurementcontrolequipmenttorealizeboth-waymultinodeserialcommunications.Itisalsocalledlow-levelcontrolnetworkforopen,digitalandmultiplespotcommunications.

Application:

FlowControlSystemofManufacturing;

ProcessControlSystem;

TrafficControl&

Management;

BuildingAutomation.Features:

Fieldbuscontrolsystemislow-levellow-bandwidthdigitalcommunicationandcontrolnetworkinindustrialsystemaswellasopensystemconnectingmicrocomputerizedappearance.Intelligentinstrumentandcontrollerareequaltomicrocomputer.TheymakeupnetworkwithFieldbuscontrolsystemasthelinkstocompletedigitalcommunicationandothertasks.

（2）DifferencebetweenFCSandDCS,FCSisupdatedcontrolsystemafterDCSintegratedwithdigitalcontrolsystemanddistributingcontrolsystem.ItsolvestheproblemthatintraditionalDCS,devicesmadebydifferentmanufacturerscannotbeconnected.Theycan'

trealizeexchangeandoperationtoorganizeannetworksystemwithwiderrangeofinformationsharing.ItconquersthedefectthatspecialclosedsystemfornetworkshouldbeusedforcommunicationinDCStorealizevariousfunctionsofintegratedautomation.ItturnsthedistributingstructurecombiningconcentrationwithdeconcentrationinDCSintonew-typefulldistributingstructure.Itreleasesthecontrolfunctiontothefieldthoroughlyandmakesitpossibletorealizebasiccontrolfunctionbymeansoffieldbusequipmentitself.FCSbreaksthetraditionalstructureformofcontrolsystem.Thetraditionalanalogcontrolsystemadoptsone-to-oneequipmenttie-wireandputsupconnectionsrespectivelyaccordingtocontrolloop.FCSadoptsintelligentfieldequipmenttoplacethecontrolmodule,allinput/outputmodulesthatusedtobeinthecontrolchamberofDCSintofieldequipment.Sincefieldequipmenthasabilitytocommunicate,thefieldmeasuringandtransferringinstrumentscantransfersignalstoactuatingmechanismsuchasvalvedirectly.Itscontrolfunctioncanbefulfilleddirectlyonthespotindependentofthecomputerorcontrolmeterinthecontrolchamber,whichrealizesthoroughdecentralizedcontrol.

FCSadoptsdigitalsignalstoreplaceanalogsignalssothatmultiplesignals（includingmultipleoperatingparametervalues,devicestatusandfailureinformation）canbetransferredonapairofcables.Meanwhile,itcangivepowersupplytoseveraldevices.Noswitchedblockforanalog/digitalordigital/analogisneededbesidesfieldbus.

（3）CharacteristicsofFCS

●OpenSystem;

●Interoperability;

●replaceabilityofdevicesmadebydifferentmanufacturers.

●IntelligentizeandAutonomy;

●Fieldequipmentcompletingbasicfunctionsofautomaticcontrol.

●DecentralizedSystemStructure;

●FieldAdaptability;

●RelativelyStrongInterferenceKillingFeatureandSafety

●Intelligentizedlocalequipmentcansaveinvestmentandquantityofhardware

●Savinginstallationexpensesandcables

●Savingdailymaintenanceexpenses

●Enhancingaccuracyandreliabilityofsystem

●Enhancinginitiativenessofsystemintegrationforusers

（4）DevelopmentBackgroundandTrendofFieldbusControlSystem,Withtherapiddevelopmentofcomputerandcomputernetwork,FCShasbeenrapidlydevelopedastheinterlinkedcommunicationnetworkbetweenthefieldintelligentdevicesinthefieldofprocessautomation,buildingandtrafficetc.BecauseFCSmeetstheneedsthatindustrialcontrolsystemisdevelopinginthewayofdecentralization,networkandintellectualized,ithasbecomethefocusofglobalindustrialautomationandbeenuniversallyconcernedbythewholeworld.FCShascausedgreatrevolutionsontheaspectsofsystemstructureandfunctionsystemforthecurrentproductionofautomationinstrument,distributingcontrolsystemandprogrammablecontroller.ItispredictedthatFCSwillbethegeneraltrendsinaverylongtimeinthefutureforesure.

2APPLICATIONOFRELAY

Theproductreliabilitygenerallyreferstotheoperatingreliability.Itisdefinedas:

theabilityofaccomplishingthespecifiedfunctionunderprescribedconditionsandinprescribedtime.Itconsistsofintrinsicreliabilityandapplicationreliability.Theintrinsicreliabilityisdeterminedbyproductdesigningandmanufacturingtechnique,andtheapplicationreliabilityisconcernedwiththecorrectapplicationofusersandtheservicesprovidedbythemanufacturerbeforeandafterselling.Whenusingrelay,theusershouldpayattentiontothefollowingitems.

2.1Coilappliedvoltage

Itisbesttochoosethecoilapplicativevoltageaccordingtotheratedvoltageindesign,orchoosethevoltageaccordingtothetemperaturerisingcurve.Usinganycoilvoltagethatislessthantheratedvoltagewillaffecttheoperationoftherelay.Thecoiloperatingvoltagereferstothevoltagethatisappliedbetweenthecoilterminals.Thevoltagevaluebetweenthetwoterminalsmustbeguaranteed,especiallywhenusingenlargementcircuittoenergizethecoil.Whereas,itwillalsoaffecttherelaycharacteristicsiftheappliedvoltageexceedsthehighestratedvoltage.Exorbitantvoltagewillbringexorbitantcoiltemperaturerising,especiallyinhightemperatureambient.Exorbitanttemperaturerisingwilldamagetheinsulatingmaterialandaffecttheworkingsafetyofrelay.Formagneticlatchingrelay,energizing（orreturn）pulsewidthshouldnotlessthan3timesoftheoperating（orreturn）time,otherwise,therelaywouldbeleftonthemiddle-positionstate.Whenusingsolid-statecomponentstoenergizethecoil,thecomponentsdielectricstrengthmustbeabove80V,andtheleakageofcurrentmustbeaslittleaspossibletoensuretherelaytorelease.

Energizingpowersource:

Under110%oftheratedcurrent,theadjustingratioofthepowersourceislessthan10%（ortheoutputimpedanceislessthan5%ofthecoilimpedance）,thewavevoltageoftheDCpowersourceislessthan5%.TheACwaveissinewave;

thewavinesscoefficientisbetween0.95~1.25;

wavedistortioniswithin±

10%;

thefrequencychangeiswithin±

1Hzor±

1%ofthespecifiedfrequency（choosingthebiggervalue）.Theoutputpowershouldnotlessthancoilpowerconsumption.

2.2Transientsuppression

Atthemomentwhenthecoilpowerisstopped,peak-inversevoltagethatismorethan30timesofthecoilratedvoltageisproducedonthecoil,whichisharmfultotheelectroniccircuit.Generally,thepeak-inversevoltageissuppressedbytransientsuppression（cutting-peak）diodeorresistancetolimitthepeak-inversevoltagewithin50V.Butthediodeinparallelconnectionwilldelay3~5timesofthereleasetime.Iftherequestofthereleasetimeishigh,asuitableresistanceinseriescanbeputtedwithandatoneendofthediode.Thepowersupplytorelaysinparallelconnectionandseriesconnection,Whenseveralrelaysinparallelconnectionaresupplied,therelaythatthepeak-inversevoltageishigherwillreleasepowertotherelaysthatthepeak-inversevoltageislower.Thereleasetimeoftherelaywilldelay.Sotherelaysinparallelconnectionshouldbecontrolledseparatelytoeliminatemutualinfluence.

Therelayswithdifferentcoilresistanceandpowercan’tbeusedinseries,otherwise,therelaythatthecoilcurrentishigherintheseriescircuitcan’toperatereliably.Onlytherelaysofthesamespecificationcanbeusedinseries,butthepeak-inversevoltagewillbeincreasedandthepeak-inversevoltageshouldbesuppressed.Resistanceinseriescanbeusedtobearthepartvoltagethatexceedstheratedvoltageofthecoilaccordingtotheratioofthedividedvoltage.

2.2.1Contactload

Theloadappliedtothecontactsshouldbeaccordanttotheratedloadandcharacteristicsofthecontacts.Aloadthatisnotappliedaccordingtotheratedvaluerangewillcauseproblem.TherelaythatisonlysuitableforDCloadcan’tbeusedinACoccasions.Therelaythatcanswitch10Aloadcan’talwaysreliablyoperateinlowlevelload（lessthan10mA×

6A）orindrycircuitoccasions.Therelaythatcanswitchsingle-phaseACpowersourceisn’talwayssuitabletoswitchtwosingle-phaseACloadsthataren’tsynchronous;

therelaythatisonlyspecifiedtoswitchtheloadofAC50Hz（or60Hz）can’tbeusedtoswitchACloadof400Hz.

2.2.2Parallelandseriesconnectionofcontacts

Thecontactsusedinparallelconnectioncan’tincreasetheloadcurrent,becausetheoperatingtimesofseveralsetsofcontact