一种基于ARM的无线自动抄表与控制系统设计.docx
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一种基于ARM的无线自动抄表与控制系统设计
DesignofaWirelessARM-BasedAutomatic
MeterReadingandControlSystem
Chih-HungWu,Shun-ChienChangandYu-WeiHuang
powerparametersandcontrolsignaltoreachthegoalofload
Abstract--ThispaperimplementsawirelessARM-basedmanagementandpowerdemandcontrol.Usingautomaticautomaticmeterreadingandcontrolsystem(WAMRCS)fordistributionautomation.TheWAMRCSisdesignedbasedona32-bitARMmicroprocessortodealwithpowerdataprocessing
andrelaycontrol.Inordertoprovideacost-effective,wireless,
always-connected,two-waydatalinkbetweenutilitycompanyandWAMRCS,theWAMRCSsendsinformationofutilityusage,powerqualityandoutagealarmtoutilitycompanyviaGPRSnetwork.Comparedwithanalogutilitymeterreadingbymanpower,WAMRCSismoreaccurate,reliable,cost-effective,quickandfreefromman-madeerrors.Itcanprovideextra
capabilitiessuchasdistributionautomation,loadmanagement
andtime-of-userate.
IndexTerms—ARM-BasedSystem,AutomaticMeterReading,GPRS,RelayControl.I.INTRODUCTIONW
iththerapidgrowthofpopulationandtechnology,theelectricpowerconsumptionandnumberofutility-consumershadincreasedquickly.Inordertoservelarger
utility-consumers,utilitycompanyneedstoemployeemorereading-meterworkers.Duringtheprocessofreadingmeterandwritingdownutilityusageonrecordtablebyworkers,man-madeerrorsoftenhappened.Thereforeutilitycompanyspentcostandmanpowertocorrecttheseerrorsforutility-consumers.Otherwiseitisuneconomicalforutilitycompanytodispatchworkerstorecordutilityusageonutility-consumers-scatteredwidearea.
Someutility-consumersastechnologyfactoriescareaboutqualityofpowersupply,butanalogpowermetercan’tgiveenoughinformationaboutpowerquality.Whenthepowersupplyisunstableoroutageoccurstoutility-consumers,how
theutilitycompanyknowstheabovestatusandthenclearspowerfaultsquicklytodecreasetheutility-consumers’loss.It’sanimportantpointtoresearch.
Atpresenttherearemoreandmorestudiesapplyingtwo-waycommunicationtechnologiesondistribution
automation[1]-[4].ThesestechnologiescansendalotofChih-HungWuisLectureofDepartmentofElectricalEngineering,Chien
KuoInstituteofTechnology,R.O.C.(e-mail:
zhwu@cc.ckit.edu.tw).
Shun-ChienChangiswithDepartmentofElectricalEngineering,NationalChang-HuaUniversityofEducation,R.O.C.(e-mail:
boboffice@.tw).
Yu-WeiHuangisProfessorofDepartmentofElectricalEngineering,NationalChang-HuaUniversityofEducation,R.O.C.(e-mail:
huangyw@cc.ncue.edu.tw).
systemofreadingmeterondistributionautomationcansupplymanycapabilitiessuchasefficientmeter-reading,distribution,powermonitoringandcontrol,loadmanagement
andtime-of-userate.Supplyingabovecapabilitiesisadevelopmenttendencytopromoteservicequalityforutility-consumersandimprovethemanagementefficiencyforutility
companyinthefuture.
IInthepast,mostautomatedmeterreading(AMR)weregenerallybasedonsuchmediaaspowerlinecarrier
communication(PLC),radiofrequency(RF),telephonelineandnetworktosenddata[5]-[7].Theabovecommunicationmediafactsomeproblemssuchastransmissiondistance,transmissioncost,maintenanceandsecurityofdata
transmission.nordertosolvetheseproblems,wecan
considerapplyingmobilecommunicationsystemGPRS
(GeneralPacketRadioService),whichispopularlyusedintheworld,tosendpowerdata.
Withrapidgrowthofinternetandmobilecommunicationnetwork,futureapplicationservicewillgraduallyconcentrateondatatransmissionservice.GPRShasbeendevelopedmaturelyandhasmanypracticalapplicationsatpresent[8]-[12].Ithasmanyadvantagessuchasalwayson-line,high-speedtransmissionandchargedfeeaccordingtotheamountoftransmitteddata.Itcansatisfytheneedofsendingpowerparametersonautomaticsystemofreadingdigitalmeter.
Therefore,GPRSsystemcanbuildoutdoor,mobile,wide-rangeandMultipoint-to-Multipointdatatransmissionchannelandsatisfytheneedofdatatransmissionspeedforautomaticsystemofreadingdigitalmeter.
Underconsiderationstoregionalsurroundings,lawsandregulations,communicationefficiency,interferenceandtransmissioncost,thisstudyproposesawirelessARM-based
automaticmeterreadingandcontrolsystem(WAMRCS).TheWAMRCSusessamplingcircuitandA/Dconverterto
transferanalogsignalofvoltageandcurrentintodigitaldata.Thedigitaldatathenissendtoembeddedsystemtocompute
powerparameters.Thisembeddedsystemwillsendpower
parameterstoregionalmonitoringandcontrolcenterofutilitycompanyviaGPRSmoduleconnectedwithit.ThisWAMRCSappliedondistributionautomationcansavepersonnelexpenseofhiringreading-meterworkersandcanbefreefromhumaninvolvement;moreover,itcansavelargemanpowerfromkeyingutilityusageintodatabase.
andthenconvertedintoanequivalentdigitalsignalbythe
ThehardwarearchitectureandappearanceofsystemareA/Dconverter.shownasFig.1andFig.2.WeusePTandCTtomeasuretheB.RCUanalogsignalofvoltageandcurrent.TheanalogsignalisTheRCUisaninterruptingdevicedesignedforfaultsampledbysample-and-holdcircuitandtransferredintointerruptionandloadswitching.InordertoprotecttheD/AdigitaldatabyA/Dconverter.Thedigitaldatathenissenttoconverterfromexceedingcurrent,theD/AconverterisARM-basedembeddedsystemtocomputepowerparameters.connectedwithprotectiverelaywiredinserieswiththeThisembeddedsystemcommunicateswithregionalcenterofbreakercontrolcircuit,sothebreakercouldbecontrolled.utilitycompanyforreportingpowerparametersandstatus
periodicallyviaGPRSmoduleconnectedwithit.TheUPSisC.AESusedtoprovidestablepowersupplyfortheembeddedsystemTraditionalpowermeasureinstruments,likewatthourandbackuppowertopreventfromshort-termoutage.meterandreactivepowermeter,cannotsupplyenoughTheWAMRCScanbedividedintofiveparts,thesefiveinformationaboutpowerquality.InordertoacquireRMSpartsseparatelyaresignalsamplingunit(SSU),relaycontrolvalueofvoltageandcurrent,powerfactor,realpower,unit(RCU),ARM-basedembeddedsystem(AES),wirelessreactivepowerandapparentpower,moreandmoredesignerscommunicationmodule(WCM)andutilitycontrolcenterusemicroprocessortodesigndigitalreadingmeters.The(UCC).Thehardwaredescriptionoffivepartsisintroducedmicroprocessor-baseddigitalpowermetershavebeenasfollows.availableinthelaboratoryandonthemarketintherecent
years[5]-[7],[13],[14].TheARM-basedsystemoccupiesA.SSU
smallspace.Itsupportmostpopularcommunicationprotocols
Theanalogsignalscaleofvoltageandcurrentontheanditscapabilitiesaremorepowerfulthan8051chip.TheprimaryisproportionallytransformedonthesecondaryviaARM-basedsystemhasbeenwidelyusedinavarietyofPTandCTtransformers.TheSSUusessample-and-holdnetworkequipments,suchasmobilephoneandPDA,andcircuittoquicklystoretheinstantaneousamplitudeofabecomepopularandcheaperatpresent.TheARM-basedsampledinputsignal,andthentoholdthatamplitudeuntiltheembeddedsystemhasasimpleoperationsystem,sonextsamplingpulse.Duringtheholdtime,thesampledprogrammercanusepopularclanguagetodesignprogram.voltageorcurrentwouldbechosenalternatelybymultiplexer
II.WAMRCSSYSTEMARCHITECTURE
UtilityControlCenter
(UCC)
Fig.1.SystemHardwareArchitecture
D.WCM
TheWAMRCSadoptsMC35TerminalGPRSmodule
producedbySiemensCorporationaswirelesscommunication
module.ThisuniversallyusableGPRSmodulesupportsboth
theGSM900andtheGSM1800networks.Ithashighspeed
ofwirelessvoiceanddatatransmission.TheMC35Terminal
GPRSmoduleoffersclass8GPRSdatacommunicationin
additiontoclassicGSMservicesandmobileinternetaccess
achievesaperformancelevelpreviouslyonlyavailablein
fixednetworks.ItcanbeintegratedsimplyviastandardRS-
232interfaces[16].
E.UCC
Fig.2.AppearanceofWAMRCSTheUCCresidesintheutilitycompanyandhasaPCascontrolserverwithneededprogramsandstoragetoreadandThisstudyadoptsNET-StartembeddedsystemproducedcollectpowerparametersfromAESviacommunicationbyWSCORECorporationtodesignWAMRCS.Thenetwork.Thespecificationsofserverareasfollows:
specificationsandcapabilitiesofNET-Startembeddedsystem2.4GHzIntelPentiumIIIprocessoraredescribedasfollows[15]:
512MegabytesRAM
(1)tisdesignedbasedonalowpower32-bit80GigabyteHardDiskITMnetworkprocessorcalledARM7TDM15"LCDMonitorI"S3C4510TM".S3C4510TMisahighperformanceandDVD-RomDrivelowcostsolutionfornetworkapplications.FloppyDiskDriveI
(2)S3C4510TMincludes8-kbytecache/SRAM,andRS-232100Mbps.NetworkConnectionserialinterface,twoUARTs,twotimers,18Dot-matrixprinterprogrammableI/Oports,anda10/100BaseTEthernet
controller.TheonchipfeaturescansignificantlyreduceIII.AESSOFTWAREARCHITECTUREthetotalsystemcosttodesignnetworkdevices.ThefunctionblocksdiagramofAESsoftwareisshownas(3)TheNET-Startembeddedsystemhas2MBflashROM
and16MBSDRAMonboard,soitcanexecutelongerFig.3.ThefunctionsofAESsoftwarearemeasurementsprogrammingcodeandhaslargerRAMtostoremoreacquisition,relaycontrol,tamperdetection,AESsetup,power
parameterscomputationanddatabasemanagement.TheAESdata.
softwarerunsundertheµClinuxoperationsystem.
Fig.3.FunctionBlocksDiagramofAESSoftware
A.µClinuxoperationsystemApparentpower:
VA=rms×