電子信息工程-外文翻譯-外文文獻(xiàn)-英文文獻(xiàn)-文獻(xiàn)翻譯

TechnologyandApplicationofFieldbusControlSystem---------IntelligentEquipment&MeasurementAndControlSystemBasedonDeviceNetPromotedbythenewtechnologicalrevolutionthatautomationcontroltechnologyistendingdigitizationandinternetinthefieldofautomationindustry,ShanghaiAtonElectricCo.,Ltd.developedIntelligentEquipment&MeasurementAndControlSystemBasedonDeviceNetasahighandnewtechnologyindustrializationmodelproject.Itwasastatehi-techdevelopmentprojectof2000andwasapprovedbytheStateCommitteeofTechnology.ShanghaiAtonElectricCo.,Ltd.constructedproductionlineofintelligentcontrollerofpumpandvalve,relyingonShanghaiElectric(Group)Corporation;constructedmeasurementandcontrolsystemFCSR&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.2APPLICATIONOFRELAYTheproductreliabilitygenerallyreferstotheoperatingreliability.Itisdefinedas:theabilityofaccomplishingthespecifiedfunctionunderprescribedconditionsandinprescribedtime.Itconsistsofintrinsicreliabilityandapplicationreliability.Theintrinsicreliabilityisdeterminedbyproductdesigningandmanufacturingtechnique,andtheapplicationreliabilityisconcernedwiththecorrectapplicationofusersandtheservicesprovidedbythemanufacturerbeforeandafterselling.Whenusingrelay,theusershouldpayattentiontothefollowingitems.2.1CoilappliedvoltageItisbesttochoosethecoilapplicativevoltageaccordingtotheratedvoltageindesign,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.2.2TransientsuppressionAtthemomentwhenthecoilpowerisstopped,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.2.2.1ContactloadTheloadappliedtothecontactsshouldbeaccordanttotheratedloadandcharacteristicsofthecontacts.Aloadthatisnotappliedaccordingtotheratedvaluerangewillcauseproblem.TherelaythatisonlysuitableforDCloadcan’tbeusedinACoccasions.Therelaythatcanswitch10Aloadcan’talwaysreliablyoperateinlowlevelload(lessthan10mA×6A)orindrycircuitoccasions.Therelaythatcanswitchsingle-phaseACpowersourceisn’talwayssuitabletoswitchtwosingle-phaseACloadsthataren’tsynchronous;therelaythatisonlyspecifiedtoswitchtheloadofAC50Hz（or60Hz）can’tbeusedtoswitchACloadof400Hz.2.2.2PThecontactsusedinparallelconnectioncan’tincreasetheloadcurrent,becausetheoperatingtimesofseveralsetsofcontactsareabsolutelydifferent;thatistosay,thereisstillonlyasetofcontactsswitchingtheincreasedload.Thiswoulddamageorweldthecontactsandmakethecontactscan’tcloseoropen.Theparallelconnectionofthecontactscandecreasethemisplayof“break”.Buttheparallelconnectionofthecontactswouldincreasethemisplayof“freezing”.Becausethemisplayof“break”isthemainpatternofinvalidationofcontacts,theparallelconnectioncanincreasethereliabilityandcanbeusedonthepivotalpartofequipments.Buttheappliedvoltageshouldnotexceedthehighestoperatingvoltageofthecoilandshouldnotlessthan90%oftheratedvoltage,otherwise,thecoillifeandtheapplicativereliabilitywouldbedamaged.Theseriesconnectionofthecontactscanincreasetheloadvoltage.Theamountofthecontactsetsisequaltothetimesthattheloadvoltagecanbeincreased.Theseriesconnectionofcontactscandecreasethemisplayof“freezing”,butitwouldincreasethemisplayof“break”.Anyway,whenusingredundanttechnologytoincreasetheoperatingreliabilityofcontacts,thecharacteristicsandsizeandthefailuremodeofloadmustbeconsidered.2.2.3SwitchingspeedTheswitchingspeedshouldnotexceedthereciprocalof10timesofthesumofoperatingandreleasetime(times/s),otherwise,thecontactscan’tswitchonsteadily.Magneticlatchingshouldbeusedunderthepulsewidthspecifiedinthetechniquecriterion,orthecoilmaybedamaged.3RVTDISTRIBUTINGELECTRICITYINTEGRATETESTAPPARATUSBasicfunction

Measureasupervision:Threemutuallyelectricvoltage/electriccurrent/powerfactorwithagreatachievement/powerwithoutagreatachievement/electricitywithagreatachiverment/electricity/homophonic-waveelectricvoltage/homophonic-waveelectric/currentDayelectricvoltage/electriccurrentbiggestandminimumvalue/fireforthefailureElectricvoltageovertop,thelimit/lackmutuallyoftimehomophonic-waveanalyzesisupto13times.Thedataisstoredfor2months.Thedatacommunicate

RS232/485communicatingconnect，Thewayincommunicatingcanadoptthespotcommunicatingorthelongrangecommunicating.，Possibletosettleinvokeorthesolidhourinvokes,respondingtothemodificationandlongrangescontroloftheparameter.Withoutpowercompensation

Takingphysicsmeasuresasthepowerfactorwithoutagreatachievement,thepowerfactorwithagreatachievementandthedullplacewithoutpowercompensation;Y+thecombinationmethodofthe△，Y+the△connectsthelinemethod，Y+△,Y,the△connectsthelinemethod.Datamanagement

AccordingtoWINDOW98operationterrace,dataincommunicationautomaticallyreportsbornstatement,curveandpillarformdiagrams.

Circulationoftheprotection

Whenthechargedbarbedwirenetofmutuallyelectricvoltageoverpress,owetopress,andasuperlimithourfastcutoffinexpiationofcapacitor，Whenthechargedbarbedwirenetlacksmutuallyorsuperlimitintheprefaceofzerohourfastcutoffinexpiationofcapacitor.screenmanifestationChineseoperationinterface，Adopt128*64thebacklightliquidcrystaldisplay.Thesolidhourshowsthechargedbarbedwirenetrelevantparameter.viewmanifestationtoplacetheparameter.現(xiàn)場(chǎng)總線控制系統(tǒng)的技術(shù)和應(yīng)用隨著新的科學(xué)技術(shù)革命的出現(xiàn)，在自動(dòng)化工業(yè)領(lǐng)域中，自動(dòng)控制技術(shù)的發(fā)展趨向于數(shù)字化和網(wǎng)絡(luò)互聯(lián)化。上海Aton電氣有限公司在基于DeviceNet網(wǎng)絡(luò)協(xié)議研制了智能設(shè)備、智能測(cè)量法和只能控制系統(tǒng)，建立了工業(yè)化高新技術(shù)工程模型。這是2000年國(guó)家重點(diǎn)發(fā)展的高科技項(xiàng)目，并且由國(guó)家科技委員會(huì)認(rèn)可。通過(guò)上海電氣集團(tuán)，上海Aton電氣有限公司構(gòu)造了汞和閥門的智能控制器的的生產(chǎn)線；創(chuàng)立了汞和閥門的智能控制器的現(xiàn)場(chǎng)控制系統(tǒng)的研發(fā)中心，通過(guò)和上海交通大學(xué)和上海大學(xué)的合作，建立了產(chǎn)品集成的研發(fā)基礎(chǔ)；建立了汞和閥門的智能控制器的現(xiàn)場(chǎng)控制系統(tǒng)的遠(yuǎn)程診斷和服務(wù)中心；建立了汞和閥門智能控制系統(tǒng)的現(xiàn)場(chǎng)控制系統(tǒng)的培訓(xùn)中心；通過(guò)和上海交通大學(xué)洛氏實(shí)驗(yàn)室和計(jì)算機(jī)集成制造系統(tǒng)中心的合作，建立了集成產(chǎn)品研發(fā)的基礎(chǔ)。1概要（1）現(xiàn)場(chǎng)總線控制系統(tǒng)就是應(yīng)用于制造業(yè)中和應(yīng)用微機(jī)和測(cè)量控制設(shè)備來(lái)實(shí)現(xiàn)多點(diǎn)雙工的連續(xù)通信的系統(tǒng)。它也被稱為是開(kāi)放式、數(shù)字化和多點(diǎn)通信的低級(jí)控制網(wǎng)絡(luò)。應(yīng)用：制造業(yè)中流程控制系統(tǒng)過(guò)程控制系統(tǒng)交通的控制和管理智能大廈特征：現(xiàn)場(chǎng)總線控制系統(tǒng)應(yīng)用于工業(yè)系統(tǒng)中的一中低級(jí)、低帶寬的數(shù)字式化通信和控制的網(wǎng)絡(luò)，同時(shí)它一種連接微機(jī)的開(kāi)放式系統(tǒng)。智能儀表和控制器就相當(dāng)于微型計(jì)算機(jī)。智能儀表和控制器組成現(xiàn)場(chǎng)總線控制系統(tǒng)作為一種鏈接來(lái)實(shí)現(xiàn)數(shù)字通信和其他的功能。(2)現(xiàn)場(chǎng)總線和集散控制系統(tǒng)的差別現(xiàn)場(chǎng)總線控制系統(tǒng)是綜合集散控制系統(tǒng)、數(shù)字控制系統(tǒng)和分布式控制系統(tǒng)發(fā)展起來(lái)的系統(tǒng)?，F(xiàn)場(chǎng)總線控制系統(tǒng)解決了集散控制系統(tǒng)中不同廠商生產(chǎn)的設(shè)備不能連接的傳統(tǒng)毛病。在集散控制系統(tǒng)中，各設(shè)備之間不能實(shí)現(xiàn)相互間的數(shù)據(jù)交換和操作，以致不能組成一個(gè)網(wǎng)絡(luò)實(shí)現(xiàn)遠(yuǎn)程的信息共享?，F(xiàn)場(chǎng)總線控制系統(tǒng)克服了在集散控制系統(tǒng)通信中，為實(shí)現(xiàn)自動(dòng)控制的各種功能時(shí)必須用到專用的封閉式系統(tǒng)來(lái)組建網(wǎng)絡(luò)的缺點(diǎn)?，F(xiàn)場(chǎng)總線控制系統(tǒng)改變了集散控制系統(tǒng)中將各分散系統(tǒng)組合在一塊的結(jié)構(gòu)，取而代之的是一中新型的完整的分布式結(jié)構(gòu)。它完全解放了現(xiàn)場(chǎng)控制的功能，同時(shí)使通過(guò)現(xiàn)場(chǎng)總線設(shè)備來(lái)實(shí)現(xiàn)智能控制成為可能?，F(xiàn)場(chǎng)總線控制系統(tǒng)突破了傳統(tǒng)的控制系統(tǒng)的結(jié)構(gòu)方式。在傳統(tǒng)的控制系統(tǒng)中都是采用一對(duì)一的接線方式（即各個(gè)儀表之間是沒(méi)有相互聯(lián)系的），然后在根據(jù)控制回路來(lái)分別的連接這些設(shè)備的接線。現(xiàn)場(chǎng)總線控制系統(tǒng)采用智能的現(xiàn)場(chǎng)設(shè)備來(lái)作為控制模塊，所有曾經(jīng)用于集散控制系統(tǒng)中的輸入/輸出模塊都用現(xiàn)場(chǎng)儀表代替。因?yàn)楝F(xiàn)場(chǎng)設(shè)備能實(shí)現(xiàn)通信功能，所以現(xiàn)場(chǎng)測(cè)量?jī)x和傳送儀可以將現(xiàn)場(chǎng)采集到的數(shù)據(jù)來(lái)直接控制比如閥門等這些機(jī)械裝置。我們既可以通過(guò)現(xiàn)場(chǎng)的計(jì)算機(jī)來(lái)單獨(dú)實(shí)現(xiàn)系統(tǒng)的控制功能，也可以通過(guò)控制在控制室的儀表來(lái)單獨(dú)實(shí)現(xiàn)系統(tǒng)的控制功能，從而實(shí)現(xiàn)徹底的分散式控制。現(xiàn)場(chǎng)總線控制系統(tǒng)采用數(shù)字信號(hào)代替模擬信號(hào)，從而實(shí)現(xiàn)在一條電纜上傳輸更多的信號(hào)（包括真正工作的參數(shù)值、設(shè)備的運(yùn)行情況和失敗的信息）。同時(shí)，它可以同時(shí)給若干個(gè)設(shè)備供電。另外，除了現(xiàn)場(chǎng)總線外，系統(tǒng)中不在需要模/數(shù)或者數(shù)/模的轉(zhuǎn)換卡。(3)現(xiàn)場(chǎng)總線控制系統(tǒng)的特性●開(kāi)放式系統(tǒng)●互用性不同廠商生產(chǎn)的設(shè)備可以互相替用●智能化現(xiàn)場(chǎng)儀表可以實(shí)現(xiàn)自動(dòng)控制的基本功能●分散式系統(tǒng)結(jié)構(gòu)●現(xiàn)場(chǎng)適應(yīng)性●強(qiáng)大的抗沖突性和安全性●所需附加設(shè)備少●安裝費(fèi)用和所用電纜少●節(jié)省了每天的維護(hù)費(fèi)用●提高了系統(tǒng)的精確性和可靠性(4)現(xiàn)場(chǎng)總線控制系統(tǒng)的發(fā)展背景和發(fā)展前景隨著計(jì)算機(jī)和計(jì)算機(jī)網(wǎng)絡(luò)的高速發(fā)展，現(xiàn)場(chǎng)總線控制系統(tǒng)作為連接應(yīng)用于過(guò)程自動(dòng)化領(lǐng)域、智能大廈和交通系統(tǒng)中的智能設(shè)備間的通信網(wǎng)絡(luò)，也已得到了快速的發(fā)展。因?yàn)楝F(xiàn)場(chǎng)總線控制系統(tǒng)的特點(diǎn)符合工業(yè)控制系統(tǒng)發(fā)展的分散化、網(wǎng)絡(luò)化和智能化的要求，所以現(xiàn)場(chǎng)總線控制系統(tǒng)成為全球工業(yè)自動(dòng)化的焦點(diǎn)并受到全球的普遍關(guān)注?，F(xiàn)場(chǎng)總線控制系統(tǒng)已經(jīng)引發(fā)了系統(tǒng)結(jié)構(gòu)方面和自動(dòng)化器械、分布式系統(tǒng)和可編程控制器方面產(chǎn)品的巨大革命。所以可預(yù)知在不久的將來(lái)很長(zhǎng)一段時(shí)間里，現(xiàn)場(chǎng)總線控制系統(tǒng)將會(huì)成為必然趨勢(shì)。2繼電器的應(yīng)用產(chǎn)品的可靠性通常十指操作的可靠性。它是這樣定義的：就是在規(guī)定的條件和規(guī)定的時(shí)間內(nèi)完成特定的功能。它主要包括產(chǎn)品本身內(nèi)在的質(zhì)量的可靠性和產(chǎn)品在應(yīng)用時(shí)的可靠性。產(chǎn)品內(nèi)在的可靠性時(shí)由產(chǎn)品的設(shè)計(jì)和加工的技術(shù)決定的，而應(yīng)用的可靠性則是和用戶的正確使用和制造商在售前和售后提供的服務(wù)相關(guān)。在使用繼電器的時(shí)候，用戶應(yīng)該注意以下幾點(diǎn)：2.1線圈工作電壓選擇線圈的工作電壓最好是根據(jù)線圈本身的工作電壓確定，或者是通過(guò)溫度的商升曲線來(lái)選擇。只要線圈的工作電壓小于它的額定電壓，那就會(huì)影響到繼電器的正常運(yùn)轉(zhuǎn)。線圈的運(yùn)轉(zhuǎn)電壓就是指加在線圈兩端的電壓。加在線圈兩端的電壓值必須足夠大，特別是當(dāng)電路實(shí)用放大電路給線圈兩端加壓的時(shí)候。然而，當(dāng)工作電壓超過(guò)最大的額定電壓的時(shí)候同樣會(huì)影響到繼電器的工作特性。過(guò)高的電壓會(huì)使線圈的溫度升高的過(guò)快，特別是在高溫的環(huán)境下。溫度升高得過(guò)快會(huì)損壞絕緣材料和影響繼電器工作的安全。比如說(shuō)磁性吸合式繼電器，充電（或放電）的時(shí)間脈寬應(yīng)該大于線圈吸合（斷開(kāi)）的工作時(shí)間的三倍，或者繼電器會(huì)處于半吸合半斷開(kāi)的狀態(tài)。給線圈充電所用到的固定成分它的絕緣能力至少要能承受八十度以上的高壓，同時(shí)漏電流應(yīng)該盡可能小以保證線圈能夠釋放。所加電源地要求：電流應(yīng)該小于額定電流的110%，電源的可調(diào)整率應(yīng)該小于10%（或者輸出阻抗應(yīng)該小于線圈阻抗的的5%）。直流電壓源的電壓波動(dòng)率應(yīng)該小于5%。而交流電壓源必須是正弦波，同時(shí)波動(dòng)率應(yīng)該介于0.95~1.25之間，波形失真度應(yīng)該小于±10%。頻率的變化應(yīng)該介于±1HZ或者是指定頻率的±1%之間（取兩者中值比較大的那個(gè)）。輸出功率不應(yīng)該小于線圈的損耗功率。2.2瞬時(shí)抑制現(xiàn)象和措施在線圈失電的瞬間，在線圈兩邊會(huì)產(chǎn)生大于線圈額定電壓三十倍的反轉(zhuǎn)電壓，這對(duì)電子電路是非常不利的。通常可以使用一個(gè)瞬時(shí)抑制二極管或者電阻把最高反轉(zhuǎn)電壓抑制在50V以內(nèi)。但是同時(shí)并聯(lián)的二極管也會(huì)使線圈的釋放瞬間延長(zhǎng)到三到五倍。在對(duì)線圈釋放時(shí)間要求得很高得場(chǎng)合我們可以通過(guò)在二極管得一端串聯(lián)一個(gè)適合的電阻來(lái)解決這個(gè)問(wèn)題。繼電器的串、并聯(lián)接法當(dāng)幾個(gè)繼電器并聯(lián)使用時(shí)，最高反轉(zhuǎn)電壓大的繼電器的能量將會(huì)穿給最高反轉(zhuǎn)電壓低的繼電器，同時(shí)線圈的釋放時(shí)間將會(huì)延長(zhǎng)。所以并聯(lián)在一起的繼電器之間必須隔離起來(lái)，這樣才能消除互相之間的影響。線圈阻值和功率不相同的繼電器不能串聯(lián)在一起使用。否則，串在一塊的繼電器線圈額定電流大的勢(shì)必不能可靠的工作。只要同一規(guī)格的繼電器方能串在一塊使用，但是這樣一來(lái)繼電器線圈的最高反轉(zhuǎn)電壓將會(huì)升高，而這個(gè)最高反轉(zhuǎn)電壓又是必須得抑制得。通過(guò)串聯(lián)電阻可以抑制高于額定電壓中得部分電壓，具體能抑制多少則是根據(jù)線圈分離出來(lái)得電壓比例。負(fù)載要求所連接得負(fù)載必須要滿足額定負(fù)載值的要求和觸頭的特性要求。如果所接的負(fù)載值不在額定負(fù)載值的范圍內(nèi)的話就會(huì)引起一系列的問(wèn)題。如果只能接直流負(fù)載的繼電器就不能用于交流場(chǎng)合。如果拿一個(gè)能接10A大負(fù)載的繼電器用于小負(fù)載或空載的時(shí)候就不能可靠的工作。一個(gè)能接單相交流負(fù)載的繼電器也不一定就能帶動(dòng)兩路不同步的單相交流負(fù)載。如果繼電器的規(guī)格只能接50HZ或者60HZ的交流負(fù)載，那么它就肯定不能再用于400HZ的交流負(fù)載了。觸頭串、并聯(lián)連接觸頭并聯(lián)接在一塊不會(huì)增加負(fù)載電流，因?yàn)檫@些對(duì)插頭的動(dòng)作次數(shù)是絕對(duì)不同的，這就是說(shuō)，這相當(dāng)于仍然是一對(duì)觸頭在帶動(dòng)增加的這些負(fù)載。這樣會(huì)損壞這些觸頭或者會(huì)使這些觸頭焊接在一塊，同時(shí)會(huì)造成觸頭不能吸合和斷開(kāi)。觸頭的并聯(lián)連接可以降低觸頭突變的誤差，但是卻增加了零點(diǎn)漂移帶來(lái)的誤差。但是因?yàn)橛|頭突變使觸頭失效的主要樣式，所以并聯(lián)接法可以提高觸頭的可靠性，同時(shí)并聯(lián)接法都可以用于設(shè)備的關(guān)鍵部分。但是實(shí)用的線圈電壓不能高于線圈的最高工作電壓，也不應(yīng)該低于額定電壓的90%，否則線圈的壽命和可靠性就會(huì)受到影響。觸頭的串聯(lián)接法可以提高負(fù)載電壓。觸頭的數(shù)量等于負(fù)載電壓提高的次數(shù)。串聯(lián)連接可以減少零點(diǎn)漂移的誤差，但是卻會(huì)增加觸頭突變的誤差。不管如何，在使用多余的技術(shù)來(lái)提高觸頭的操作的可靠性時(shí)，必須考慮它的特性、大小和負(fù)載的失敗模式。六、轉(zhuǎn)換速度轉(zhuǎn)換的速度不能超過(guò)吸合和釋放時(shí)間之和的十倍的倒數(shù)。否則，觸頭不能穩(wěn)定地轉(zhuǎn)換。磁式繼電器的轉(zhuǎn)換速度應(yīng)該取決于由專門的技術(shù)標(biāo)準(zhǔn)規(guī)定的脈寬，否則線圈將會(huì)被損壞。3RVT配電綜合監(jiān)測(cè)儀基本功能可測(cè)量和監(jiān)控以下電量：三相電壓、三相電流、功率因數(shù)、有功功率、無(wú)功功率、有功分量、無(wú)功電量頻率、諧波電壓、諧波電流、日電壓/電流最大、最小值、電壓超上、下限缺、相時(shí)間諧波分析至13次、數(shù)據(jù)儲(chǔ)存為2個(gè)月。數(shù)據(jù)通信串行通信口RS232/485接線方式，這種通信方式既可以用于現(xiàn)場(chǎng)數(shù)據(jù)的通信，也可以用于遠(yuǎn)程數(shù)據(jù)的通信?？梢詫?shí)現(xiàn)定時(shí)和實(shí)時(shí)召喚，以響應(yīng)預(yù)置參數(shù)的修改和遠(yuǎn)程控制。無(wú)功補(bǔ)償取樣物理量為無(wú)功功率，無(wú)投切振蕩，無(wú)補(bǔ)償呆區(qū)，Y+△的組合方式、Y+△的接線方式、Y+△、Y、△接線方式。數(shù)據(jù)管理基于WINDOWS98的操作平臺(tái)，通訊數(shù)據(jù)自動(dòng)生成報(bào)表、曲線和柱狀圖。運(yùn)行保護(hù)，當(dāng)電網(wǎng)某電壓過(guò)壓、欠壓及諧波超過(guò)限時(shí)快速切初補(bǔ)償器。當(dāng)電網(wǎng)缺相或零序超限時(shí)快速切除補(bǔ)償電容器。屏幕顯示中文操作界面，采用128*64背光液晶顯示器，實(shí)時(shí)顯示電網(wǎng)有關(guān)參數(shù)，直觀顯示預(yù)置參數(shù)?；贑8051F單片機(jī)直流電動(dòng)機(jī)反饋控制系統(tǒng)的設(shè)計(jì)與研究基于單片機(jī)的嵌入式Web服務(wù)器的研究MOTOROLA單片機(jī)MC68HC（8）05PV8/A內(nèi)嵌EEPROM的工藝和制程方法及對(duì)良率的影響研究基于模糊控制的電阻釬焊單片機(jī)溫度控制系統(tǒng)的研制基于MCS-51系列單片機(jī)的通用控制模塊的研究基于單片機(jī)實(shí)現(xiàn)的供暖系統(tǒng)最佳啟停自校正（STR）調(diào)節(jié)器單片機(jī)控制的二級(jí)倒立擺系統(tǒng)的研究基于增強(qiáng)型51系列單片機(jī)的TCP/IP協(xié)議棧的實(shí)現(xiàn)基于單片機(jī)的蓄電池自動(dòng)監(jiān)測(cè)系統(tǒng)基于32位嵌入式單片機(jī)系統(tǒng)的圖像采集與處理技術(shù)的研究基于單片機(jī)的作物營(yíng)養(yǎng)診斷專家系統(tǒng)的研究基于單片機(jī)的交流伺服電機(jī)運(yùn)動(dòng)控制系統(tǒng)研究與開(kāi)發(fā)基于單片機(jī)的泵管內(nèi)壁硬度測(cè)試儀的研制基于單片機(jī)的自動(dòng)找平控制系統(tǒng)研究基于C8051F040單片機(jī)的嵌入式系統(tǒng)開(kāi)發(fā)基于單片機(jī)的液壓動(dòng)力系統(tǒng)狀態(tài)監(jiān)測(cè)儀開(kāi)發(fā)模糊Smith智能控制方法的研究及其單片機(jī)實(shí)現(xiàn)一種基于單片機(jī)的軸快流CO〈,2〉激光器的手持控制面板的研制基于雙單片機(jī)沖床數(shù)控系統(tǒng)的研究基于CYGNAL單片機(jī)的在線間歇式濁度儀的研制基于單片機(jī)的噴油泵試驗(yàn)臺(tái)控制器的研制基于單片機(jī)的軟起動(dòng)器的研究和設(shè)計(jì)基于單片機(jī)控制的高速快走絲電火花線切割機(jī)床短循環(huán)走絲方式研究基于單片機(jī)的機(jī)電產(chǎn)品控制系統(tǒng)開(kāi)發(fā)基于PIC單片機(jī)的智能手機(jī)充電器基于單片機(jī)的實(shí)時(shí)內(nèi)核設(shè)計(jì)及其應(yīng)用研究基于單片機(jī)的遠(yuǎn)程抄表系統(tǒng)的設(shè)計(jì)與研究基于單片機(jī)的煙氣二氧化硫濃度檢測(cè)儀的研制基于微型光譜儀的單片機(jī)系統(tǒng)單片機(jī)系統(tǒng)軟件構(gòu)件開(kāi)發(fā)的技術(shù)研究基于單片機(jī)的液體點(diǎn)滴速度自動(dòng)檢測(cè)儀的研制基于單片機(jī)系統(tǒng)的多功能溫度測(cè)量?jī)x的研制基于PIC單片機(jī)的電能采集終端的設(shè)計(jì)和應(yīng)用基于單片機(jī)的光纖光柵解調(diào)儀的研制氣壓式線性摩擦焊機(jī)單片機(jī)控制系統(tǒng)的研制基于單片機(jī)的數(shù)字磁通門傳感器基于單片機(jī)的旋轉(zhuǎn)變壓器-數(shù)字轉(zhuǎn)換器的研究基于單片機(jī)的光纖Bragg光柵解調(diào)系統(tǒng)的研究單片機(jī)控制的便攜式多功能乳腺治療儀的研制基于C8051F020單片機(jī)的多生理信號(hào)檢測(cè)儀基于單片機(jī)的電機(jī)運(yùn)動(dòng)控制系統(tǒng)設(shè)計(jì)Pico專用單片機(jī)核的可測(cè)性設(shè)計(jì)研究