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TechnologyandApplicationofFieldbusControlSystem---------In____igentEquipmentMeasurementAndControlSystemBasedonDevi__Net Promotedbythenewtechnologicalrevolutionthatauto__tioncontroltechnologyistendingdigitizationandinternetinthefieldofauto__tionindustryShanghaiAtonElectricCo.Ltd.developedIn____igentEquipmentMeasurementAndControlSystemBasedonDevi__Netasahighandnewtechnologyindustrializationmodelproject.Itwasastatehi-techdevelopmentprojectof2000andwasapprovedbytheStateCommitteeofTechnology.ShanghaiAtonElectricCo.Ltd.constructedproductionlineofin____igentcontrollerofpumpandvalverelyingonShanghaiElectricGroupCorporation;constructedmeasurementandcontrolsystemFCSRD__nterofin____igentcontrollerofpumpandvalveandbuiltup__ssproductionRDbasiscooperatingwithShanghaiJiaotongUniversityandShanghaiUniversity;constructedFCSremotediagnosisandservi____nterofin____igentcontrollerofpumpandvalve;constructedFCStraining__nterofin____igentcontrollerofpumpandvalve;founded__ssproductionRDbasisalongwiththeRockwellLaboratoryofShanghaiJiaotongUniversityandCIMS__nter.1Sum__ry1Fieldbuscontrolsystemisasystemappliedtofieldofproductionandmicrocomputerizedmeasurementcontrolequipmenttorealizeboth-waymultinodeserialcommunications.Itisalsocalledlow-levelcontrolnetworkforopendigitalandmultiplespotcommunications.Application:FlowControlSystemof__nufacturing;Pro__ssControlSystem;TrafficControl__nagement;BuildingAuto__tion.Features:Fieldbuscontrolsystemislow-levellow-bandwidthdigitalcommunicationandcontrolnetworkinindustrialsystemaswellasopensystemconnectingmicrocomputerizedappearan__.In____igentinstrumentandcontrollerareequaltomicrocomputer.They__keupnetworkwithFieldbuscontrolsystemasthelinkstocompletedigitalcommunicationandothertasks.2Differen__betweenFCSandDCSFCSisupdatedcontrolsystemafterDCSintegratedwithdigitalcontrolsystemanddistributingcontrolsystem.ItsolvestheproblemthatintraditionalDCSdevi__s__debydifferent__nufacturerscannotbeconnected.Theycantrealizeexchangeandoperationtoorganizeannetworksystemwithwiderrangeofinfor__tionsharing.ItconquersthedefectthatspecialclosedsystemfornetworkshouldbeusedforcommunicationinDCStorealizevariousfunctionsofintegratedauto__tion.Itturnsthedistributingstructurecombiningcon__ntrationwithdecon__ntrationinDCSintonew-typefulldistributingstructure.Itreleasesthecontrolfunctiontothefieldthoroughlyand__kesitpossibletorealizebasiccontrolfunctionbymeansoffieldbusequipmentitself.FCSbreaksthetraditionalstructureformofcontrolsystem.Thetraditional____ogcontrolsystemadoptsone-to-oneequipmenttie-wireandputsupconnectionsrespectivelyaccordingtocontrolloop.FCSadoptsin____igentfieldequipmenttopla__thecontrolmoduleallinput/outputmodulesthatusedtobeinthecontrolchamberofDCSintofieldequipment.Sin__fieldequipmenthasabilitytocommunicatethefieldmeasuringandtransferringinstrumentscantransfersignalstoactuatingmechani__suchasvalvedirectly.Itscontrolfunctioncanbefulfilleddirectlyonthespotindependentofthecomputerorcontrolmeterinthecontrolchamberwhichrealizesthoroughde__ntralizedcontrol.FCSadoptsdigitalsignalstorepla______ogsignalssothatmultiplesignalsincludingmultipleoperatingparametervaluesdevi__statusandfailureinfor__tioncanbetransferredonapairofcables.Meanwhileitcangivepowersupplytoseveraldevi__s.Noswitchedblockfor____og/digitalordigital/____ogisneededbesidesfieldbus.3CharacteristicsofFCS●OpenSystem;●Interoperability;●repla__abilityofdevi__s__debydifferent__nufacturers.●In____igentizeandAutonomy;●Fieldequipmentcompletingbasicfunctionsofauto__ticcontrol.●De__ntralizedSystemStructure;●FieldAdaptability;●RelativelyStrongInterferen__KillingFeatureandSafety●In____igentizedlocalequipmentcans__einvestmentandquantityofhardware●S__inginstallationexpensesandcables●S__ingdaily__intenan__expenses●Enhancingaccuracyandreliabilityofsystem●Enhancinginitiativenessofsystemintegrationforusers4DevelopmentBackgroundandTrendofFieldbusControlSystemWiththerapiddevelopmentofcomputerandcomputernetworkFCShasbeenrapidlydevelopedastheinterlinkedcommunicationnetworkbetweenthefieldin____igentdevi__sinthefieldofpro__ssauto__tionbuildingandtrafficetc.BecauseFCSmeetstheneedsthatindustrialcontrolsystemisdevelopinginthewayofde__ntralizationnetworkandin____ectualizedithasbecomethefocusofglobalindustrialauto__tionandbeenuniversallycon__rnedbythewholeworld.FCShascausedgreatrevolutionsontheaspectsofsystemstructureandfunctionsystemforthecurrentproductionofauto__tioninstrumentdistributingcontrolsystemandprogram__blecontroller.ItispredictedthatFCSwillbethegeneraltrendsinaverylongtimeinthefutureforesure.2APPLICATIONOFRELAYTheproductreliabilitygenerallyreferstotheoperatingreliability.Itisdefinedas:theabilityofaccomplishingthespecifiedfunctionunderprescribedconditionsandinprescribedtime.Itconsistsofintrinsicreliabilityandapplicationreliability.Theintrinsicreliabilityisdeterminedbyproductdesigningand__nufacturingtechniqueandtheapplicationreliabilityiscon__rnedwiththecorrectapplicationofusersandtheservi__sprovidedbythe__nufacturerbeforeandafterselling.Whenusingrelaytheusershouldpayattentiontothefollowingitems.
2.1CoilappliedvoltageItisbesttochoosethecoilapplicativevoltageaccordingtotheratedvoltageindesignorchoosethevoltageaccordingtothetemperaturerisingcurve.Usinganycoilvoltagethatislessthantheratedvoltagewillaffecttheoperationoftherelay.Thecoiloperatingvoltagereferstothevoltagethatisappliedbetweenthecoilterminals.Thevoltagevaluebetweenthetwoterminalsmustbeguaranteedespeciallywhenusingenlargementcircuittoenergizethecoil.Whereasitwillalsoaffecttherelaycharacteristicsiftheappliedvoltageex__edsthehighestratedvoltage.Exorbitantvoltagewillbringexorbitantcoiltemperaturerisingespeciallyinhightemperatureambient.Exorbitanttemperaturerisingwillda__getheinsulating__terialandaffecttheworkingsafetyofrelay.For__gneticlatchingrelayenergizingorreturnpulsewidthshouldnotlessthan3timesoftheoperatingorreturntimeotherwisetherelaywouldbeleftonthemiddle-positionstate.Whenusingsolid-statecomponentstoenergizethecoilthecomponents___lectricstrengthmustbeabove80Vandtheleakageofcurrentmustbeaslittleaspossibletoensuretherelaytorelease.Energizingpowersour__:Under110%oftheratedcurrenttheadjustingratioofthepowersour__islessthan10%ortheoutputimpedan__islessthan5%ofthecoilimpedan__thew__evoltageoftheDCpowersour__islessthan5%.TheACw__eissinew__e;thew__inesscoefficientisbetween
0.95~
1.25;w__edistortioniswithin±10%;thefrequencychangeiswithin±1Hzor±1%ofthespecifiedfrequencychoosingthebiggervalue.Theoutputpowershouldnotlessthancoilpowerconsumption.
2.2TransientsuppressionAtthemomentwhenthecoilpowerisstoppedpeak-inversevoltagethatismorethan30timesofthecoilratedvoltageisprodu__donthecoilwhichisharmfultotheelectroniccircuit.Generallythepeak-inversevoltageissuppressedbytransientsuppression(cutting-peak)diodeorresistan__tolimitthepeak-inversevoltagewithin50V.Butthediodeinparallelconnectionwilldelay3~5timesofthereleasetime.Iftherequestofthereleasetimeishighasuitableresistan__inseriescanbeputtedwithandatoneendofthediode.ThepowersupplytorelaysinparallelconnectionandseriesconnectionWhenseveralrelaysinparallelconnectionaresuppliedtherelaythatthepeak-inversevoltageishigherwillreleasepowertotherelaysthatthepeak-inversevoltageislower.Thereleasetimeoftherelaywilldelay.Sotherelaysinparallelconnectionshouldbecontrolledseparatelytoeliminatemutualinfluen__.Therelayswithdifferentcoilresistan__andpowercan’tbeusedinseriesotherwisetherelaythatthecoilcurrentishigherintheseriescircuitcan’toperatereliably.Onlytherelaysofthesamespecificationcanbeusedinseriesbutthepeak-inversevoltagewillbeincreasedandthepeak-inversevoltageshouldbesuppressed.Resistan__inseriescanbeusedtobearthepartvoltagethatex__edstheratedvoltageofthecoilaccordingtotheratioofthedividedvoltage.
2.
2.1ContactloadTheloadappliedtothecontactsshouldbeaccordanttotheratedloadandcharacteristicsofthecontacts.Aloadthatisnotappliedaccordingtotheratedvaluerangewillcauseproblem.TherelaythatisonlysuitableforDCloadcan’tbeusedinACoccasions.Therelaythatcanswitch10Aloadcan’talwaysreliablyoperateinlowlevelloadlessthan10__×6Aorindrycircuitoccasions.Therelaythatcanswitchsingle-phaseACpowersour__isn’talwayssuitabletoswitchtwosingle-phaseACloadsthataren’tsynchronous;therelaythatisonlyspecifiedtoswitchtheloadofAC50Hz(or60Hz)can’tbeusedtoswitchACloadof400Hz.
2.
2.2ParallelandseriesconnectionofcontactsThecontactsusedinparallelconnectioncan’tincreasetheloadcurrentbecausetheoperatingtimesofseveralsetsofcontactsareabsolutelydifferent;thatistosaythereisstillonlyasetofcontactsswitchingtheincreasedload.Thiswouldda__georweldthecontactsand__kethecontactscan’tcloseoropen.Theparallelconnectionofthecontactscandecreasethemisplayof“break”.Buttheparallelconnectionofthecontactswouldincreasethemisplayof“freezing”.Becausethemisplayof“break”isthe__inpatternofinvalidationofcontactstheparallelconnectioncanincreasethereliabilityandcanbeusedonthepivotalpartofequipments.Buttheappliedvoltageshouldnotex__edthehighestoperatingvoltageofthecoilandshouldnotlessthan90%oftheratedvoltageotherwisethecoillifeandtheapplicativereliabilitywouldbeda__ged.Theseriesconnectionofthecontactscanincreasetheloadvoltage.Theamountofthecontactsetsisequaltothetimesthattheloadvoltagecanbeincreased.Theseriesconnectionofcontactscandecreasethemisplayof“freezing”butitwouldincreasethemisplayof“break”.Anywaywhenusingredundanttechnologytoincreasetheoperatingreliabilityofcontactsthecharacteristicsandsizeandthefailuremodeofloadmustbeconsidered.
2.
2.3SwitchingspeedTheswitchingspeedshouldnotex__edthereciprocalof10timesofthesumofoperatingandreleasetimetimes/sotherwisethecontactscan’tswitchonsteadily.__gneticlatchingshouldbeusedunderthepulsewidthspecifiedinthetechniquecriterionorthecoil__ybeda__ged.3RVTDISTRIBUTINGELECTRICITYINTEGRATETESTAPPARATUSBasicfunctionMeasureasupervision:Threemutuallyelectricvoltage/electriccurrent/powerfactorwithagreatachievement/powerwithoutagreatachievement/electricitywithagreatachiverment/electricity/homophonic-w__eelectricvoltage/homophonic-w__eelectric/currentDayelectricvoltage/electriccurrentbiggestandminimumvalue/fireforthefailureElectricvoltageovertopthelimit/lackmutuallyoftimehomophonic-w__e____yzesisupto13times.Thedataisstoredfor2months.ThedatacommunicateRS232/485communicatingconnect,Thewayincommunicatingcanadoptthespotcommunicatingorthelongrangecommunicating.,Possibletosettleinvokeorthesolidhourinvokesrespondingtothemodificationandlongrangescontroloftheparameter.WithoutpowercompensationTakingphysicsmeasuresasthepowerfactorwithoutagreatachievementthepowerfactorwithagreatachievementandthedullpla__withoutpowercompensation;Y+thecombinationmethodofthe△,Y+the△connectsthelinemethod,Y+△Ythe△connectsthelinemethod.Data__nagementAccordingtoWINDOW98operationterra__dataincommunicationauto__ticallyreportsbornstatementcurveandpillarformdiagrams.CirculationoftheprotectionWhenthechargedbarbedwirenetofmutuallyelectricvoltageoverpressowetopressandasuperlimithourfastcutoffinexpiationofcapacitor,Whenthechargedbarbedwirenetlacksmutuallyorsuperlimitintheprefa__ofzerohourfastcutoffinexpiationofcapacitor.screen__nifestationChineseoperationinte_____,Adopt128*64thebacklightliquidcrystaldisplay.Thesolidhourshowsthechargedbarbedwirenetrelevantparameter.view__nifestationtopla__theparameter.现场总线控制系统的技术和应用随着新的科学技术__的出现,在自动化工业领域中,自动控制技术的发展趋向于数字化和网络互联化__Aton电气有限公司在基于Devi__Net网络协议研制了智能设备、智能测量法和只能控制系统,建立了工业化高新技术工程模型这是2000年国家重点发展的高科技项目,并且由国家科技委员会认可通过__电气集团,__Aton电气有限公司构造了汞和阀门的智能控制器的的生产线;创立了汞和阀门的智能控制器的现场控制系统的研发中心,通过和__交通大学和__大学的合作,建立了产品集成的研发基础;建立了汞和阀门的智能控制器的现场控制系统的远程诊断和服务中心;建立了汞和阀门智能控制系统的现场控制系统的培训中心;通过和__交通大学洛氏实验室和计算机集成制造系统中心的合作,建立了集成产品研发的基础1概要
(1)现场总线控制系统就是应用于制造业中和应用微机和测量控制设备来实现多点双工的连续通信的系统它也被称为是开放式、数字化和多点通信的低级控制网络应用制造业中流程控制系统过程控制系统交通的控制和管理智能大厦特征现场总线控制系统应用于工业系统中的一中低级、低带宽的数字式化通信和控制的网络,同时它一种连接微机的开放式系统智能仪表和控制器就相当于微型计算机智能仪表和控制器组成现场总线控制系统作为一种链接来实现数字通信和其他的功能2现场总线和集散控制系统的差别现场总线控制系统是综合集散控制系统、数字控制系统和分布式控制系统发展起来的系统现场总线控制系统解决了集散控制系统中不同厂商生产的设备不能连接的传统毛病在集散控制系统中,各设备之间不能实现相互间的数据交换和操作,以致不能组成一个网络实现远程的信息共享现场总线控制系统克服了在集散控制系统通信中,为实现自动控制的各种功能时必须用到专用的封闭式系统来组建网络的缺点现场总线控制系统改变了集散控制系统中将各分散系统组合在一块的结构,取而代之的是一中新型的完整的分布式结构它完全解放了现场控制的功能,同时使通过现场总线设备来实现智能控制成为可能现场总线控制系统突破了传统的控制系统的结构方式在传统的控制系统中都是采用一对一的接线方式(即各个仪表之间是没有相互__的),然后在根据控制回路来分别的连接这些设备的接线现场总线控制系统采用智能的现场设备来作为控制模块,所有曾经用于集散控制系统中的输入/输出模块都用现场仪表代替因为现场设备能实现通信功能,所以现场测量仪和传送仪可以将现场采集到的数据来直接控制比如阀门等这些机械装置我们既可以通过现场的计算机来单独实现系统的控制功能,也可以通过控制在控制室的仪表来单独实现系统的控制功能,从而实现__的分散式控制现场总线控制系统采用数字__代替模拟__,从而实现在一条电缆上传输更多的__(包括真正工作的参数值、设备的运行情况和失败的信息)同时,它可以同时给若干个设备供电另外,除了现场总线外,系统中不在需要模/数或者数/模的转换卡3现场总线控制系统的特性●开放式系统●互用性不同厂商生产的设备可以互相替用●智能化现场仪表可以实现自动控制的基本功能●分散式系统结构●现场适应性●强大的抗冲突性和安全性●所需附加设备少●__费用和所用电缆少●节省了每天的维护费用●提高了系统的精确性和可靠性4现场总线控制系统的发展背景和发展前景随着计算机和计算机网络的高速发展,现场总线控制系统作为连接应用于过程自动化领域、智能大厦和交通系统中的智能设备间的通信网络,也已得到了快速的发展因为现场总线控制系统的特点符合工业控制系统发展的分散化、网络化和智能化的要求,所以现场总线控制系统成为全球工业自动化的焦点并受到全球的普遍__现场总线控制系统已经引发了系统结构方面和自动化器械、分布式系统和可编程控制器方面产品的巨大__所以可预知在不久的将来很长一段时间里,现场总线控制系统将会成为必然趋势2继电器的应用产品的可靠性通常十指操作的可靠性它是这样定义的就是在规定的条件和规定的时间内完成特定的功能它主要包括产品本身内在的质量的可靠性和产品在应用时的可靠性产品内在的可靠性时由产品的设计和__的技术决定的,而应用的可靠性则是和用户的正确使用和制造商在售前和售后提供的服务相关在使用继电器的时候,用户应该注意以下几点
2.1线圈工作电压选择线圈的工作电压最好是根据线圈本身的工作电压确定,或者是通过温度的商升曲线来选择只要线圈的工作电压小于它的额定电压,那就会影响到继电器的正常运转线圈的运转电压就是指加在线圈两端的电压加在线圈两端的电压值必须足够大,特别是当电路实用放大电路给线圈两端加压的时候然而,当工作电压超过最大的额定电压的时候同样会影响到继电器的工作特性过高的电压会使线圈的温度升高的过快,特别是在高温的环境下温度升高得过快会损坏绝缘材料和影响继电器工作的安全比如说磁性吸合式继电器,充电(或放电)的时间脉宽应该大于线圈吸合(断开)的工作时间的三倍,或者继电器会处于半吸合半断开的状态给线圈充电所用到的固定成分它的绝缘能力至少要能承受八十度以上的高压,同时漏电流应该尽可能小以保证线圈能够释放所加电源地要求电流应该小于额定电流的110%,电源的可调整率应该小于10%(或者输出阻抗应该小于线圈阻抗的的5%)直流电压源的电压波动率应该小于5%而交流电压源必须是正弦波,同时波动率应该介于
0.95~
1.25之间,波形失真度应该小于±10%频率的变化应该介于±1HZ或者是指定频率的±1%之间(取两者中值比较大的那个)输出功率不应该小于线圈的损耗功率
2.2瞬时抑制现象和措施在线圈失电的瞬间,在线圈两边会产生大于线圈额定电压三十倍的反转电压,这对电子电路是非常不利的通常可以使用一个瞬时抑制二极管或者电阻把最高反转电压抑制在50V以内但是同时并联的二极管也会使线圈的释放瞬间延长到三到五倍在对线圈释放时间要求得很高得场合我们可以通过在二极管得一端串联一个适合的电阻来解决这个问题
1、继电器的串、并联接法当几个继电器并联使用时,最高反转电压大的继电器的能量将会穿给最高反转电压低的继电器,同时线圈的释放时间将会延长所以并联在一起的继电器之间必须隔离起来,这样才能消除互相之间的影响线圈阻值和功率不相同的继电器不能串联在一起使用否则,串在一块的继电器线圈额定电流大的势必不能可靠的工作只要同一规格的继电器方能串在一块使用,但是这样一来继电器线圈的最高反转电压将会升高,而这个最高反转电压又是必须得抑制得通过串联电阻可以抑制高于额定电压中得部分电压,具体能抑制多少则是根据线圈分离出来得电压比例
2、负载要求所连接得负载必须要满足额定负载值的要求和触头的特性要求如果所接的负载值不在额定负载值的范围内的话就会引起一系列的问题如果只能接直流负载的继电器就不能用于交流场合如果拿一个能接10A大负载的继电器用于小负载或空载的时候就不能可靠的工作一个能接单相交流负载的继电器也不一定就能带动两路不同步的单相交流负载如果继电器的规格只能接50HZ或者60HZ的交流负载,那么它就肯定不能再用于400HZ的交流负载了
3、触头串、并联连接触头并联接在一块不会增加负载电流,因为这些对插头的动作次数是绝对不同的,这就是说,这相当于仍然是一对触头在带动增加的这些负载这样会损坏这些触头或者会使这些触头焊接在一块,同时会造成触头不能吸合和断开触头的并联连接可以降低触头突变的误差,但是却增加了零点漂移带来的误差但是因为触头突变使触头失效的主要样式,所以并联接法可以提高触头的可靠性,同时并联接法都可以用于设备的关键部分但是实用的线圈电压不能高于线圈的最高工作电压,也不应该低于额定电压的90%,否则线圈的寿命和可靠性就会受到影响触头的串联接法可以提高负载电压触头的数量等于负载电压提高的次数串联连接可以减少零点漂移的误差,但是却会增加触头突变的误差不管如何,在使用多余的技术来提高触头的操作的可靠性时,必须考虑它的特性、大小和负载的失败模式
六、转换速度转换的速度不能超过吸合和释放时间之和的十倍的倒数否则,触头不能稳定地转换磁式继电器的转换速度应该取决于由专门的技术标准规定的脉宽,否则线圈将会被损坏3RVT配电综合监测仪基本功能可测量和监控以下电量三相电压、三相电流、功率因数、有功功率、无功功率、有功分量、无功电量频率、谐波电压、谐波电流、日电压/电流最大、最小值、电压超上、下限缺、相时间谐波分析至13次、数据储存为2个月数据通信串行通信口RS232/485接线方式,这种通信方式既可以用于现场数据的通信,也可以用于远程数据的通信可以实现定时和实时召唤,以响应预置参数的修改和远程控制无功补偿取样物理量为无功功率,无投切振荡,无补偿呆区,Y+△的组合方式、Y+△的接线方式、Y+△、Y、△接线方式数据管理基于WINDOWS98的操作平台,通讯数据自动生成报表、曲线和柱状图运行保护,当电网某电压过压、欠压及谐波超过限时快速切初补偿器当电网缺相或零序超限时快速切除补偿电容器屏幕显示中文操作界面,采用128*64背光液晶显示器,实时显示电网有关参数,直观显示预置参数。