电力远程自动抄表系统外文翻译.docx
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电力远程自动抄表系统外文翻译
英文原文:
Automaticmeterreadingsystem
Thepresentinventionrelatestoautomaticmeterreading.Moreparticularly,thepresentinventionrelatestoanautomatedsystemforremotelymonitoringapluralityofutilitymetersoncommandfromahostserverviaanRFoutboundbroadcast.
BACKGROUNDOFTHEINVENTION
Historically,metersmeasuringelectricalenergy,waterflow,gasusage,andthelikehaveusedmeasurementdevices,whichmechanicallymonitorthesubscriber'susageanddisplayareadingoftheusageatthemeteritself.Consequently,thereadingofthesemetershasrequiredthathumanmeterreadersphysicallygotothesiteofthemeterandmanuallydocumentthereadings.Clearly,thisapproachreliesveryheavilyonhumaninterventionand,thus,isverycostly,time-consuming,andpronetohumanerror.Asthenumberofmetersinatypicalutility'sserviceregionhasincreased,insomecasesintothemillions,humanmeterreadinghasbecomeprohibitiveintermsoftimeandmoney.
Inresponse,varioussensingdeviceshavebeendevelopedtoautomaticallyreadutilitymetersandstorethemeterdataelectronically.Thesesensingdevices,usuallyoptical,magnetic,orphotoelectricinnature,arecoupledtothemetertorecordthemeterdata.Additionally,themetershavebeenequippedwithradiofrequency(RF)transceiversandcontroldeviceswhichenablethemeterstotransmitmeterdataoveranRFlinkwhenrequestedtodoso.Hand-helddeviceshavebeendevelopedwhichincludeRFtransceiversdesignedtointerfacewiththemeters'RFtransceivers.Thesehand-helddevicesenablethehumanmeterreadertosimplywalkbythemeter'slocation,transmitareadingrequestoveranRFlinkfromthehand-helddevicetothemeter'sreceivingdevice,waitforaresponsefromthemeter'ssensingandtransmittingdevice,andthenrecord,manuallyorelectronically,themeterdata.
Similarly,meterreadingdeviceshavebeendevelopedfordrive-byreadingsystems.UtilityvansareequippedwithRFtransceiverssimilartothosedescribedinthehand-heldexampleabove.Thehumanmeterreaderdrivesbythesubscriber'slocation,withanautomatedreadingsystemintheutilityvan.Again,themetersarecommandedtoreportthemeterdata,whichisreceivedinthevanviaanRFlink,wherethedataisrecordedelectronically.Whilethismethodologyimprovesuponthepreviousapproaches,itstillrequiresasignificantamountofhumaninterventionandtime.
Recently,therehasbeenaconcertedefforttoaccomplishmeterreadingbyinstallingfixedcommunicationnetworksthatwouldallowdatatoflowfromthemeterallthewaytothehostsystemwithouthumanintervention.Thesefixedcommunicationsnetworkscanoperateusingwirelineorradiotechnology.
FIG.1showsaconventionalfixedcommunicationnetworkforautomatedmeterreading(AMR)technology.AsshowninFIG.1,afixedcommunicationnetworkhavingwirelinetechnologyinwhichutilitymeters10areconnectedtoawideareanetwork(WAN)consistingofasuitablecommunicationsmedium,includingordinarytelephonelines,orthepowerlinesthatfeedthemetersthemselves.
Onedisadvantageofthisapproachhasbeenthatwhenanumberofmeterstransmitmeterdatanearlysimultaneously,theinherentlatencyonthewideareanetworkresultsinpacketcollisions,lostdata,garbleddata,andgeneraldegradationofintegrityacrossthesystem.Tocompensateforthecollisionsandinterferencebetweendatapackagesdestinedforthecentralcomputer,duetothelatencyinherentintheWAN,variousmanagementschemeshavebeenemployedtoensurereliabledeliveryofthemeterdata.However,whilethisapproachmaybesuitableforsmallsystems,itdoesnotservetheneedsofautilitywhichmonitorsthousandsorevenmillionsofmeters.
InanattempttobettermanagethetrafficintheWAN,approacheshavebeendevelopedwhereinmetercontroldevicessimilartothosedescribedabovehavebeenprogrammedtotransmitmeterdatainresponsetocommandsreceivedfromthecentralcomputerviatheWAN.Bylimitingthenumberofmeterreadingcommandstransmittedatagiventime,thecentralcomputercontrolsthevolumeofdatatransmittedsimultaneously.However,theadditionalWANtrafficfurtheraggravatedthedegradationofdataintegrityduetovariousWANlatencyeffects.Thus,whiletheseapproachesmayservetoeliminatetheneedforhumanmeterreaders,relianceontheWANhasproventheseapproachestobeunsatisfactoryforservicingthenumberofmetersinthetypicalserviceregion.
Consequently,radiotechnologyhastendedtobethemediumofchoiceduetoitshigherdataratesandindependenceofthedistributionnetwork.ThelatestevolutionofautomatedmeterreadingsystemshavemadeuseofoutboundRFcommunicationsfromafixedsource(usuallytheutility'scentralstation),directlytoRFreceiversmountedonthemeters.Themetersarealsoequippedwithcontroldeviceswhichinitiatethetransferofmeterdatawhencommandedtodosobythefixedsource.ThemetersrespondviaaWANasinthepreviouswire-basedexample.OnedisadvantageoftheseapproachesisthatthereisstillfartoomuchinterferenceontheWANwhenallofthemetersrespondataboutthesametime.Thus,whiletheseapproachesreducesomeoftheWANtraffic(byeliminatingoutboundcommandsovertheWAN),theyarestillunabletoaccommodatethelargenumberofmetersbeingpolled.
Itisworthyofnotethatthewire-basedsystemstypicallyuseasinglefrequencychannelandallowtheimpedanceandtransfercharacteristicsofthetransformersinthesubstationtopreventinjectionequipmentinonestationfrominterferingwithreceiversinanotherstation.Thisbuilt-inisolationinthenetworkmakestimedivisionmultiplexinglesscriticalthanforradiobasedmeteringsystems.Typicalfixednetworkradiosystemsalsoutilizeasinglechanneltoreadallmetersbutthesystemsdonothaveanaturalblockingpointsimilartothesubstationtransformerutilizedbydistributionlinecarrier(DLC)networks.Also,thelatencyinherentintheWANhascontributedsignificantlytotheproblemsassociatedwithtimedivisionmultiplexingasinglefrequencycommunicationssystems.Asaresult,thesystemsrequiresophisticatedmanagementschemestotimedivisionmultiplexthechannelforoptimalutilization.
Therefore,aneedexiststoprovideasystemwherebyautilitycompanycanreliablyandrapidlyreadontheorderofonemillionmetersintheabsenceofanysignificanthumanintervention.Further,aneedexiststoprovidesuchasystemwhichaccommodateschangestothenetworkaswellaschangesinoperatingconditionswithoutsignificantdegradationofperformance.
SUMMARYOFTHEINVENTION
Thepresentinventionfulfillstheseneedsbyprovidinganautomatedmeterreadingsystemhavingahostserverinterfacedtoapluralityofnodes,eachnodecommunicatingwithanumberofutilitymeters.Inapreferredembodiment,thesystemhasaselectionmeansforselectingagroupofnon-interferingnodes;andanoutboundRFbroadcastchannelfromthehostserverforcommunicatingwiththeselectedgrouptoinitiatethereadingofmetersthatcommunicatewiththosenodesandtheuploadingofmeterdataprovidedbythosemeterstothosenodes.ThisoutboundRFbroadcastchannelcanbeanexistingchannelcurrentlybeingusedfordemandsidemanagement.Inapreferredembodiment,thesystemalsohasatwo-waycommunicationlinkoverawideareanetworkbetweenthehostserverandeachofthenodes.Inamorepreferredembodiment,thehostserverreceivesmeterdatareadfromatleastonemillionmetersinnomorethanaboutfiveminutes.
Inyetanotherpreferredembodiment,thesystemalsohasanumberofgateways,eachcommunicatingwithapluralityofnodes,groupedtoformsetsofnon-interferinggateways.Inthisembodiment,thesystemalsohasaselectionmeansforselectingoneofthesetsofnon-interferinggateways,andasecondoutboundRFbroadcastchannelfromthehostserverforcommunicatingwiththeselectedsettoinitiateuploadingofmeterdatafromtheselectedsettothehostserver.ThissecondoutboundRFbroadcastchannelcanbeanexistingchannelcurrentlybeingusedfordemandsidemanagement.
ThepresentinventionfurtherfulfillstheseneedsbyprovidingamethodforusinganoutboundRFchanneltoautomaticallyreadmeters.Inapreferredembodiment,themethodcomprisesthestepsof:
defininganumberofgroupsofnon-interferingnodes:
selectingafirstgroup;broadcastingareadcommandtoeachnodeinthefirstgroup;selectingasecondgroup;andbroadcastingareadcommandtoeachnodeinthesecondgroup.
Inanotherembodiment,themethodfurthercomprisesthestepsof:
readingmeterdata,inresponsetothereadcommand,fromeachmetercommunicatingwiththenodereceivingthereadcommand;recordingthemeterdatainadatastoragemeansassociatedwiththatnode;broadcastinganuploadmessagetoeachnodeinthefirstgroup;uploadingthemeterdatarecordedinthedatastoragemeansassociatedwiththenodesofthefirstgrouptothehostserver;broadcastinganuploadmessagetoeachnodeinthesecondgroup;anduploadingthemeterdatarecordedinthedatastoragemeansassociatedwithnodesofthesecondgrouptothehostserver.
Inyetanotherembodiment,atleastsomeofthenodescommunicatethroughoneofanumberofgatewaystothehostserver.Inthisembodiment,themethodfurthercomprisesthestepsof:
selectingafirstsetofnon-interferinggateways;broadcastinganuploadmessagetoeachgatewayinthefirstset;uploadingthemeterdatarecordedinthedatastoragemeansassociatedwiththenodesthatcommunicatewiththefirstsetofnon-interferinggatewaystothehostserver;selectinga