distribution reliability report - final (1).pdf

7/28/2019 Distribution Reliability Report - Final (1).pdf

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U.S.DepartmentofEnergy|December2012

TableofContentsExecutiveSummary................................................................................................................. ii1. Introduction..................................................................................................................... 1

1.1 PurposeandScope.......................................................................................................11.2 BackgroundonElectricDistributionReliability............................................................ 21.3 OrganizationofthisReport..........................................................................................3

2. OverviewofSystems,Devices,andExpectedBenefits...................................................... 42.1 CommunicationsNetworks..........................................................................................42.2 InformationandControlSystems.................................................................................52.3 FieldDevices................................................................................................................. 82.4 ExpectedBenefits.......................................................................................................11

3. SGIGDistributionReliabilityProjectsandDeploymentProgress.................................... 143.1 DeploymentProgress.................................................................................................163.2 ProjectExamples........................................................................................................17

4. AnalysisofInitialResults................................................................................................204.1 AggregatedResults..................................................................................................... 204.2 FeederGroupSpecificResults....................................................................................214.3 SummaryofObservations..........................................................................................23

5. NextSteps ......................................................................................................................25

AppendixA.ReliabilityIndices.....................................................................................................A 1AppendixB.IEEEReliabilityBenchmarkData..............................................................................B1AppendixC.SupplementaryAnalysisResults.............................................................................. C1AppendixD.SGIGElectricDistributionReliabilityProjects.........................................................D 1AppendixE.OverviewofFeederSwitchingOperations..............................................................E1

ReliabilityImprovementsInitialResults Pagei


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ExecutiveSummaryTheU.S.DepartmentofEnergy(DOE),OfficeofElectricityDeliveryandEnergyReliability(OE),isimplementing

the

Smart

Grid

Investment

Grant

(SGIG)

program

under

the

American

Recovery

andReinvestmentActof2009.TheSGIGprograminvolves99projectsthataredeployingsmartgridtechnologies,tools,andtechniquesforelectrictransmission,distribution,advancedmetering,andcustomersystems.1Ofthe99SGIGprojects,48areseekingtoimproveelectricdistributionsystemreliability.Ingeneral,theseprojectsseektoachieveoneormoreofthefollowingdistributionreliabilityobjectives:(1)reducingthefrequencyofbothmomentaryandsustainedoutages,(2)reducingthedurationofoutages,and(3)reducingtheoperationsandmaintenancecostsassociatedwithoutagemanagement.Achievingthesedemandsideobjectivesresultinthefollowingbenefits:

Higherlevelsofproductivityandfinancialperformanceforbusinessesandgreaterconvenience,savingsfromlessfoodspoilage,andavoidanceofmedicalandsafetyproblemsforconsumers

Enhancedsystemflexibilitytomeetresiliencyneedsandaccommodateallgenerationanddemandsideresources

LowercostsofelectricityandmoreopportunitiestokeepratesaffordableThisreportpresentsinformationabouttheseprojectsonthetypesofdevicesandsystemsbeingdeployed,deploymentprogressasofJune30,2012,expectedbenefits,andinitialresults.Thereportdiscussesthenewcapabilitiesbeingimplementedincludingenhancedoutagedetection,automatedfeederswitching,andremotediagnosisandnotificationoftheconditionofdistributionequipment.Ofthe48SGIGelectricdistributionreliabilityprojects,42areimplementingautomatedfeederswitchingmakingitthemostprevalentapproachintheSGIGprogramforachievingdistributionreliabilityobjectives.AnalysisofInitialResultsMostofthedistributionreliabilityprojectsareintheearlystagesofimplementationandhavenotfinisheddeploying,testing,andintegratingfielddevicesandsystems.However,four1Forfurtherinformation,seetheSmartGridInvestmentGrantProgramProgressReport,July2012,whichcanbe

foundatwww.smartgrid.gov.

ReliabilityImprovementsInitialResults Pageii
http:///reader/full/www.smartgrid.govhttp:///reader/full/www.smartgrid.gov


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projectsreportedinitialresultstoDOEOEbasedonoperationalexperiencesthroughMarch31,2012.Theyarecalledinitialresultsbecausethefourprojectsarestilloptimizingtheirsystemsandtheyrepresentonlyabout10%ofthe42SGIGdistributionreliabilityprojectsthataredeployingautomatedfeederswitching. Additionaldatareceivedoverthenexttwoyearswillbeneededtoobtainabetterunderstandingoftheimpacts.TableES1providesasummaryoftheinitialresultsfromthefourprojects,andcoversatotalof1,250distributionfeeders.ThetableshowsthechangesinthemajorreliabilityindicesdueprimarilytoautomatedfeederswitchingandisbasedonarangeofresultsthatweremeasuredduringsummerandwinterperiodsfromApril1,2011toMarch31,2012.2Thereliabilityindicesshowninthetablearetheonescommonlyusedbytheelectricpowerindustrytoestimatechangesinreliability.3Thechangeswerecalculatedfrombaselinesthattheprojectsestimatedusingatleastthreeyearsofhistoricaldata.Negativechangesindicatethereliabilityindicesareimprovingwhilepositivechangesindicatethereliabilityindicesaregettingworse.Theresultsshowarangeofobservedreliabilitychangesfromautomatedfeederswitching,withSAIFIandMAIFIshowingimprovementsinallcases,andSAIDIandCAIDIshowingmixedresults.ReliabilityIndices Description RangeofPercentChanges

SAIFI SystemAverageInterruptionFrequencyIndex(outages) 11%to 49%MAIFI MomentaryAverageInterruptionFrequencyIndex(interruptions) 13%to 35%SAIDI SystemAverageInterruptionDurationIndex(minutes) +4%to 56%CAIDI CustomerAverageInterruptionDurationIndex(minutes) +29%to 15%

TableES1.ChangesinReliabilityIndicesfromAutomatedFeederSwitchingObservationsAdditionalinformationwillbecollectedandanalyzedacrossmoreprojects,feeders,andtimeperiodstodevelopamorecomprehensiveunderstandingofthechangesinreliability.Observationsfromtheinitialresultsinclude:

2ProjectsusedtheIEEEGuideforElectricPowerDistributionReliabilityIndicesStandard1366TM2003and

excludedmajorevents.3AppendixAprovidesdefinitionsandtheformulaforcalculatingthereliabilityindicesandAppendixBprovides

benchmarkinformationfortheseindices.

ReliabilityImprovementsInitialResults Pageiii


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Projectswithautomatedfeederswitchingwereabletoreducethefrequencyofoutages,thenumberofcustomersaffectedbybothsustainedoutagesandmomentaryinterruptions,andthetotalamountoftimethatcustomerswerewithoutpower(asmeasuredbycustomerminutesinterrupted).Ingeneral,thesechangeswereinlinewiththeexpectationsoftheprojects.

Projectsaregenerallyapplyingautomatedfeederswitchingtotheirworstperformingfeeders.Theresultsshowthatthegreatestpercentageimprovementsinreliabilityfromautomatedfeederswitchingoccurwhenappliedontheworstperformingfeeders.

Inmostcases,theprojectswerenotyetusingthefullsetofautomatedcapabilities.Forexample,manyprojectsalsoplantousedistributionmanagementsystemsforaccomplishingautomatedfeederswitching,andnoneofthefourreportingprojectshadthisfeaturefullyoperationalyet.Thisunderscorestheneedforfurtherdataandanalysisasmanyoftheprojectsplantousethisfeatureinthefuture.

Severaloftheprojectshadmorepriorexperiencewithautomatedfeederswitchingthanothers.Theprojectsreportasubstantiallearningcurveforgridoperators,equipmentinstallers,andfieldcrewsinfiguringoutthefullsetofcapabilitiesandhowtousethemtotheirbestadvantage.Theprojectswithmoreexperiencereportedhavingmoreconfidenceinthegridimpactsandreliabilityimprovementstheyobserved.

Projectspursuedbothcentralizedanddistributedformsofcontrolsystemsforautomatedfeederswitching,dependingontheircircumstancesandobjectives.Therelativemeritsofthesetwoapproaches,andthecircumstanceswhentheybestapply,areimportantconsiderations.

TheinitialresultsraisequestionsabouttheusefulnessofCAIDIasanindexformeasuringtheeffectsofautomatedfeederswitchingonthedurationofcustomerinterruptions.Thisisbecauseautomatedfeederswitchinggenerallyreducesthenumberofcustomersexperiencingsustainedoutages(reducingthedenominatoroftheindex),relativetothedurationofthesustainedoutages(expressedinthenumerator.)

NextStepsAsdiscussed,thefocusofthisreportisontheimpactsofautomatedfeederswitching.Futurereportswillanalyzeautomatedfeederswitchingingreaterdetailandwithmoredata.Inaddition,theimpactsofotherdistributionreliabilitycapabilitieswillalsobeanalyzedincludingfaultandoutagedetectionandnotification,andequipmenthealthmonitoring.Improvementsinoperationsandmaintenancecostsfromdistributionreliabilityupgradeswillalsobeassessed.DOEOEwillcontinuetoworkwiththeprojectsandotherindustrystakeholderstoassessthesesmartgridapplicationsandtheireffectsonthereliabilityindices.

ReliabilityImprovementsInitialResults Pageiv


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Whileallofthe48SGIGdistributionreliabilityprojectswillultimatelyhaveimportantinformationandfindingstoshare,DOEOEwillfocusitsanalysisontheonesthataremostabletoprovidequantitativedataandresults.Inthenextyear,manymoreoftheprojectswillbemeasuringchangesindistributionreliability,includingthefourincludedinthisreport.DOEOEplanstoconductfollowupanalysispresentingadditionalresultsfromSGIGdistributionreliabilityprojectsinthefuture.Inthemeantime,updatesondeploymentprogressandcasestudieshighlightingprojectexamplesarepostedregularlyonwww.smartgrid.gov.

ReliabilityImprovementsInitialResults Pagev


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1. IntroductionTheU.S.DepartmentofEnergy(DOE),OfficeofElectricityDeliveryandEnergyReliability(OE),isimplementingtheSmartGridInvestmentGrant(SGIG)programundertheAmericanRecoveryandReinvestmentActof2009.TheSGIGprograminvolves99projectsthataredeployingsmartgridtechnologies,tools,andtechniquesforelectrictransmission,distribution,advancedmetering,andcustomersystems.DOEOErecentlypublishedtheSmartGridInvestmentGrantProgramProgressReport(July2012)toprovideinformationaboutthedeploymentstatusofSGIGtechnologiesandsystems,examplesofsomeofthekeylessonslearned,andinitialaccomplishments.

4

DOEOEisanalyzingtheimpacts,costs,andbenefitsoftheSGIGprojectsandispresentingtheresultsthroughaseriesofimpactanalysisreports.Thesereportscoveravarietyoftopics,including:

Peakdemandandelectricityconsumptionreductionsfromadvancedmetering

infrastructure,customersystems,andtimebasedrateprograms Operationalimprovementsfromadvancedmeteringinfrastructure Reliabilityimprovementsfromautomatingdistributionsystems Efficiencyimprovementsfromadvancedvolt/voltamperereactive(VAR)controlsin

distributionsystems Efficiencyandreliabilityimprovementsfromapplicationsofsynchrophasortechnologies

inelectrictransmissionsystems1.1 PurposeandScopeThisimpactanalysisreportpresentsinformationonthe48SGIGprojectsseekingtoimproveelectricdistributionsystemreliability,specificallythetypesofdevicesbeingdeployed,systemsbeingimplemented,deploymentprogress,expectedbenefits,andinitialresults.Ingeneral,theSGIGelectricreliabilityprojectsseektoachieveoneormoreofthefollowingdistributionreliabilityobjectives:(1)reducingthefrequencyandcustomersaffectedbybothmomentaryandsustainedoutages,(2)reducingthedurationofoutages,and(3)reducingtheoperationsandmaintenancecostsassociatedwithoutagemanagement.Inachievingtheseobjectives,theprojectsareapplyingavarietyofnewcapabilitiesincludingenhancedfaultandoutagedetectionandnotification,automatedfeederswitching,andremotediagnosisandnotificationoftheconditionofdistributionequipment.4DOEOE,SmartGridInvestmentGrantProgramProgressReport,July2012,www.smartgrid.gov.

ReliabilityImprovementsInitialResults Page1


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Mostofthe48SGIGdistributionreliabilityprojectsareinearlystagesofimplementationandhavenotfinisheddeploying,testing,andintegratingthesmartgriddevicesandsystems.Thedatainthisreportrepresentthefirsttimetheprojectshavereportedimpacts.Fouroftheprojects,representing1,250feeders,havereportedtoDOEOEaboutinitialresultsbasedonoperationalexperiencesthroughMarch31,2012.Thefourprojectsupgraded870,185,120,and75feeders,respectively.Theinitialresultspresentedinthisreportincludefeedersthathaveautomatedfeederswitchinginstalledandoperational,buttheequipmenthasnotyetbeenfullyintegratedwithdistributionmanagementsystems.GridimpactinformationisreportedtoDOEOEbytheprojectsasaveragesoversixmonthperiodsandiscomparedwithpreestablishedbaselines.Baselineswerecalculatedbyeachprojectusingthreeormoreyearsofhistoricaldataandcoveringtimeperiodsbeforedistributionautomationdevicesandsystemswereimplemented.1.2 BackgroundonElectricDistributionReliabilityThereliabilityofelectricdistributionsystemsiscriticallyimportantforbothutilitiesandcustomers.Electricreliabilityaffectspublichealthandsafety,economicgrowthanddevelopment,andsocietalwellbeing.Manyutilitiesestimatethevalueofelectricservicestoconsumerstoassessthebenefitsofinvestmentstoimprovereliability.5Mostpoweroutagesarecausedbyweatherrelateddamagetooverheadpowerlines.Highwinds,ice,andsnowcancausetreestotouchpowerlines,andsometimescancauselinesandpoles

to

break.

Animal

contact,

vehicle

accidents,

equipment

failure,

and

human

error

also

contributetopoweroutages.Poweroutagesinelectricdistributionsystemsaredocumentedandclassifiedbythenumberofcustomersaffectedandthelengthoftimethatpowerisout.TheInstituteofElectricalandElectronicEngineers(IEEE)specifiesthreetypesofoutages:

MajorEventsarethosethatexceedthereasonabledesignand/oroperationallimitsoftheelectricpowersystemandaffectalargepercentageofthecustomersservedbytheutility.

6

5LawrenceBerkeleyNationalLaboratory,EstimatedValueofServiceReliabilityforElectricUtilityCustomersin

theUnitedStatesLBNL2132E,June2009.6TherecentlypublishedIEEEStandard1366TM2012containsthepreferredapproachfordeterminingmajor

events.However,thisstandardwasnotavailableatthetimetheanalysispresentedinthisreportwasconducted.



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SustainedInterruptionsincludeoutagesnotclassifiedasmomentaryeventsandthatlastformorethanfiveminutes.

MomentaryInterruptionsinvolvethebrieflossofpowertooneormorecustomerscausedbyopeningandclosingofinterruptiondevices.

Reliabilityindicesarecommonlyusedtoassessoutagesandevaluatetheperformanceofelectricsystems.FortheSGIGprogram,DOEOErequestedthattheprojectsusethedefinitionsandcalculationmethodslistedintheIEEEGuideforElectricPowerDistributionReliabilityIndicesIEEEStandard1366TM2003.7Thesearethestandardindicesusedbytheelectricpowerindustryandprovideauniformmethodologyfordatacollectionandanalysis.Majoreventdaysareexcludedfromtheindicestobetterrevealtrendsindailyoperations.Theindicesusedfortheanalysisinclude:

SystemAverageInterruptionFrequencyIndex(SAIFI) MomentaryAverageInterruptionFrequencyIndex(MAIFI) SystemAverageInterruptionDurationIndex(SAIDI) CustomerAverageInterruptionDurationIndex(CAIDI)

1.3 OrganizationofthisReportSection2ofthisreportprovidesinformationonthetypesofdevicesandsystemsbeingdeployedbytheSGIGelectricdistributionreliabilityprojectsandtheirexpectedbenefits.Section3providesinformationonthestatusofdeploymentincludingdetailsaboutthespecificreliabilityobjectivestheprojectsaretryingtoachieve.Section4providesasummaryoftheDOEOEanalysisofthefourdistributionreliabilityprojectsthatreportedinitialresults.Section5discussesnextstepsforDOEOEanalysisoftheSGIGelectricdistributionreliabilityprojects.Fourappendicesprovidesupplementaryinformation.AppendixAprovidesinformationonthedefinitionsofthereliabilityindices.AppendixBprovidesbenchmarkdataonthereliabilityindicesfromtheIEEEDistributionReliabilityWorkingGroup.AppendixCprovidesanalysisdetailsoftheresultsforthefourprojects.AppendixDprovidesatableofthe48SGIGelectricdistributionreliabilityprojects,summariesofdeploymentprogress,andcertainoftheplannedimplementationactivities.AppendixEprovidesanoverviewofautomatedfeederswitchingoperations.

7Goingforward,IEEE1366TM2012willbeused.



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2. OverviewofSystems,Devices,andExpectedBenefitsThissectionprovidesanoverviewofthedevicesandsystemsthattheSGIGdistributionreliabilityprojectsaredeploying,aswellasthebenefitsthesedevicesandsystemsareexpectedtoprovide,including:

Communicationnetworks, Informationandcontrolsystems, Fielddevices,and Expectedbenefits.

Toimplementautomateddistributioncapabilitiesproperly,itisnecessarytointegratecommunicationsnetworks,controlsystems,andfielddevices.Inaddition,testingandevaluationisrequiredtodeterminewhethertheequipmentisperformingasdesigned.Trainingofgridoperatorsandfieldcrewsisalsorequiredtoensuresafeandefficientuseofthetechnologies.Forexample,smartrelays,automatedfeederswitches,anddistributionmanagementsystemscanbecoordinatedtoimplementfaultlocation,isolation,andservicerestoration(FLISR)operations.Itisthusimportanttounderstandhowthedevicesandsystemsworktogether,inadditiontounderstandhowtheyworkontheirown,asutilitiestypicallypursueapproachesthatinvolvevaryingdegreesofcoordination.

2.1

CommunicationsNetworks

Communicationsnetworksfordistributionsystemsmakeitpossibletoacquiredatafromsensors,processthedata,andsendcontrolsignalstooperateequipment.Theapplicationofcommunicationsnetworksforthesepurposesenhancesthecapabilitiesofgridoperatorstomanagepowerflowsandaddressreliabilityissues.Mostutilitiesusemultilayeredsystemstocommunicatebetweeninformationandcontrolsystemsandfielddevices.Inmanycases,twolayercommunicationsnetworksareused.Typically,thefirstlayerofthenetworkconnectssubstationsanddistributionmanagementsystemsatheadquarterlocationsandconsistsofhighspeed,fiberopticormicrowavecommunicationssystems.Someutilitiesuseexistingsupervisorycontrolanddataacquisition(SCADA)communicationssystemsforthislayer.Thesecondlayerofthenetworktypicallyconnectssubstationswithfielddevicesanduseswirelessnetworksorpowerlinecarriercommunications.



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2.2 InformationandControlSystemsEquipmentAutomationApproachesAutomatedfeederswitchingisaccomplishedthroughautomaticisolationandreconfigurationofsegmentsofdistributionfeedersusingsensors,controls,switches,andcommunicationssystems.Automatedfeederswitchescanopenorcloseinresponsetoafaultconditionidentifiedlocallyortoacontrolsignalsentfromanotherlocation.Whencombinedwithcommunicationsandcontrols,theoperationofmultipleswitchescanbecoordinatedtoclearfaultedportionsoffeedersandreroutepowertoandfromportionsthathavenotexperiencedfaults.Thesecoordinatedactionsarecalledfaultlocation,isolation,andservicerestoration.FLISRactionscanreducethenumberofcustomerswhoexperiencesustainedoutagesandtheaveragedurationofoutages.TheperformanceofFLISRsystemsdependsonseveralfactors,including(1)thetopologyofthefeeders(i.e.,radial,looped,andnetworked),(2)loadingconditions,(3)thenumberoffeedersegmentsaffected,and(4)thecontrolapproachesimplemented.AppendixEprovidesexamplesoffeederswitchingoperations.Ingeneral,therearetwomaintypesofautomationapproaches:centralizedanddecentralized.CentralizedswitchinginvolvesdistributionmanagementsystemsorSCADAtocoordinateautomatedequipmentoperationsamongmultiplefeeders.Decentralizedswitching(alsosometimescalleddistributedorautonomousswitching)useslocalcontrolpackagestooperateautomatedequipmentonspecificfeedersaccordingtopreestablishedswitchinglogics.Manyprojects

are

using

acombination

of

centralized

and

decentralized

approaches.

TheamountoftimeittakestoaccomplishFLISRactionsdependsonthesequenceofevents,fielddevices,andtheextentoflatencyinthecommunicationssystems.CentralizedsystemstakemorefactorsintoaccountwhendeterminingswitchingstrategiesandtakelongertoperformFLISR,buttheyincludemoreswitchingoptionsifthereareloadingissuesorothercomplications.DecentralizedsystemstypicallyswitchbetweenafewpredeterminedfeedersandareabletoperformFLISRmorequickly.Thedifferentfeederswitchingdevices,systems,andapproachesdependontheprojectsobjectives,legacyequipmentandsystems,longtermgridmodernizationgoals,andinvestmenttimetables.Projectsthatseektoaddressasmallgroupoffeedersthatarehighlyvulnerabletooutagesmayfavoradistributedapproach,whileprojectsthatseektoimprovereliabilityforlargeportionsoftheirserviceterritoriesmaychooseacentralizedapproach.Otheraspectsofdistributionsystemmodernization,suchasvoltagecontrols,reactivepowermanagement,andassetmanagementalsoaffectinvestmentdecisionsinfeederswitchingapproaches.



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AutomatedControlPackagesSomeutilitiesareretrofittingexistingdistributionswitcheswithautomatedcontrolpackages,orinstallingnewswitchesequippedwiththesecontrols.Thecontrolpackagesincludecomputers,userinterfaces,andcommunicationssystemsthatenableequipmenttobeprogrammedandcontrolledremotely.TwoexamplesareshowninFigure1.

Figure1.ExamplesofAutomatedControlPackagesThesedevicesusevoltageandcurrentsensorstodetectfaults.Thecontrollersopenandclosetheswitchesindependently,orincombinationwithotherswitches,dependingontheprogrammedlogicandsystemconditions.ThiscapabilityisessentialtobalancingfeederloadsduringFLISRoperationswithoutdamagingequipment.Controlpackagescanalsobeoperatedremotelybyoperatorsordistributionmanagementsystems.Dependingonthespecificneeds,controlpackagescanhavemorecomplexalgorithmsthatcanrespondtochangingsystemconditionsoroperationalobjectives.Forexample,withseverestormsapproaching,switchescanbeprogrammednottoreclosebasedontheexpectationthatmostfaultscouldnotbeclearedwithreclosing.Thiscapabilitycanavoidproblemsthatarisefromunnecessaryreclosingandfromfaultcurrentsonportionsofthesystemthatwouldultimatelygooutofservicebecauseofstormdamage.DistributionManagementSystemsDistributionmanagementsystems(DMS)integratedifferentsourcesofdatafromsensors,monitors,andotherfielddevicestoassessconditionsandcontrolthegrid.Theyactasvisualizationanddecisionsupportsystemstoassistgridoperatorswithmonitoringandcontrollingdistributionsystems,components,andpowerflows.DMSaretypicallyusedtomonitorthesystemforfeederandequipmentconditionsthatmaycontributetofaultsand



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outages,identifyfaults,anddetermineoptimalswitchingschemestorestorepowertothegreatestamountofloadornumberofcustomers.ADMScontinuouslyupdatesdynamicmodelsofthedistributionsysteminnearrealtimesogridoperatorscanbetterunderstanddistributionsystemconditionsatalltimes.Changesinsystemloads,outages,andmaintenanceissuesarepresentedtooperatorsthroughdashboardsandvisualizationtools.DMScanalsobeusedassimulatorsfortraininggridoperatorsandastoolstoanalyzerestorationresponsestovarioustypesofoutagescenarios.DMScanalsobeusedtoautomateorsupportvoltageandvoltamperereactive(VAR)controls,aswellasotheractivitiesthatincreasetheefficiencyofdistributionoperationsandmaintenance.OutageManagementSystemsOutagemanagementsystems(OMS),asshowninFigure2,areinformationmanagementandvisualizationtoolsthatanalyzeoutagereportstodeterminethescopeofoutagesandthelikelylocationofproblems.AnOMScompilesinformationonthetimesandlocationsofcustomercalls,smartmeteroutagenotifications,andfaultdatafromsubstationsandmonitoringdevicesonfeederlines.Typically,OMSincorporategeographicinformationsystemsthatarelinkedtocomputersusedbyrepaircrewssotheycangettopreciseoutagelocationsmorequicklyandoftenwithabetterideaoftheproblemtheywillneedtosolve.Inthepast,mostOMSoperatedwithinformationlimitedtocustomercallsandgeneralinformationaboutsubstationoutagesandbreakerpositions.Byfilteringandanalyzingoutageinformationfrommultiplesources,modernOMScanprovidegridoperatorsandrepaircrewswithmorespecificandactionableinformationtomanageoutagesandrestorationsmorepreciselyandcosteffectively,resultinginimprovedoperations.

Figure2.ExampleofaVisualDisplayfromanOutageManagementSystem



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UtilitiesalsouseOMStocommunicateoutageinformationtocustomers,includingthelikelycausesandestimatedrestorationtimes.AnOMSmaybeintegratedwithDMStoprovideadditionalinputsforvisualizationanddecisionsupportthatcanbebeneficial,particularlywhenaddressinglargeoutagesandmajorevents.2.3 FieldDevicesFielddevicescompriseasuiteoftechnologiesthatareinstalledalongfeederlinesandinsubstationsandareusedtomanagepowerflowsonthegrid.Fielddeviceoperationscanbecoordinatedwithinformationandcontrolsystemstoachieveelectricdistributionreliabilityobjectives.FaultDetectionandAutomatedFeederSwitchesSmart

relays

and

fault

analysis

applications

incorporated

with

DMS

provide

greater

accuracy

in

locatingandidentifyingfaultsandtheircauses.Remotefaultindicatorsnotifygridoperatorsandfieldcrewswhenfaultsoccurandvoltageandcurrentlevelsareoutsidenormaloperatingboundaries.Smartrelayscollectelectricalinformationaboutfaultsandusemoresophisticatedalgorithmstohelpgridoperatorswithdiagnosticanalysisofthelocationsandcausesoffaults.Thesedevicesandsystemstypicallyusehigherresolutionsensorsthatarebetterabletodetectfaultsignaturesandidentifyandaddressmomentaryinterruptions.Throughanalysisoffaultdetectiondata,utilitiescanimplementcorrectiveactions(e.g.,automatedfeederswitchingorvegetationmanagement)andreducethelikelihoodofsustainedoutages.Recentadvancesinsensorandrelaytechnologieshavealsoimprovedthedetectionofhighimpedancefaults.Thesefaultsoccurwhenenergizedpowerlinescomeincontactwithforeignobjects(e.g.,treelimbs),butthecontactproducesalowfaultcurrent.Currentsfromthesetypesoffaultsaredifficulttodetectwithconventionalrelays.Faultindicators,suchastheexamplesshowninFigure3,aresensorsthatdetectelectricsignaturesassociatedwithfaults,suchashighcurrentsorlow/novoltages.FaultindicatorscanhavevisualdisplaysinstalledwiththemtoassistfieldcrewsandcommunicationsnetworksthatareintegratedwithSCADAorDMS.Bymonitoringfaultsandtheirprecursors,utilitiescanidentifyproblemswithequipmentortreecontactswithpowerlines,andinitiatecorrectiveactionstopreventsustainedoutages.Automatedfeederswitchesopenandcloseinresponsetocontrolcommandsfromautonomouscontrolpackages,DMS,orgridoperatorcommands.Switchescanbeconfiguredtoisolatefaultsandreconfigurefaultedsegmentsofthedistributionfeedertorestorepower.Switchesarealsoconfiguredtoopenandcloseatpredeterminedsequencesandintervalswhen



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Distribution Management

Distribution ManagementSystem


Figure3.ExampleRemoteFaultIndicator

faultcurrentisdetected.Thisaction,knownasreclosing,isusedtointerruptpowerflowtoafeederthathasbeencontactedbyanobstructionandreenergizeaftertheobstructionhascleareditselffromtheline.Reclosingreducesthelikelihoodofsustainedoutageswhentreesand

other

objects

temporarily

contact

power

lines

during

storms

and

high

winds.

EquipmentHealthSensorsandLoadMonitorsEquipmenthealthsensorsmonitorconditionsandmeasureparameters,suchaspowertransformerinsulationoiltemperatures,thatcanrevealpossibilitiesforprematurefailures.Thesedevicescanbeconfiguredtomeasuredifferentparametersonmanytypesofdevices.Typically,thesedevicesareappliedonsubstationandotherequipmentwhosefailurewouldresultinsignificantconsequencesforutilitiesandcustomers.Whencoupledwithdataanalysistools,equipmenthealthsensorscanprovidegridoperatorsandmaintenancecrewswithalertsandactionableinformation.Actionsmayincludetakingequipmentoffline,transferringloadorrepairingequipment.Figure4providesanoverviewofanequipmenthealthsensornetworkformonitoringsubstationpowertransformers.

Power TransformerEquipment Health Sensors

Equipment

Health Info

Data Retrieval

For Analysis

Retrieval of

Monitored

Parameters

Figure4.IllustrationofanEquipmentHealthSensorNetworkforPowerTransformers



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Figure5isanexampleofafeedermonitorthatcanmeasureloadondistributionlinesandequipmentinnearrealtime.Whendataiscommunicatedtogridoperators,thesemeasurementscanbeusedtotriggeralarmswhenloadsreachpotentiallydamaginglevels.Loadmonitorsneedtobeintegratedwithcommunicationsnetworksandanalysistoolssothatgridoperatorscaneffectivelyassessloadingtrendsandtakecorrectiveswitchingactions,whennecessary.Thesefielddevicesareusedincoordinationwithinformationandcontrolsystemstopreventoutagesfromoccurringduetoequipmentfailureoroverloadconditions.

Figure5.ExampleFeederMonitorOutageDetectionDevicesandSmartMetersUntilrecently,mostutilitiesonlyrealizedthatcustomershadlostpowerwhenthecustomerscalledtoreporttheoutage.Notallcustomersreportoutages;thosewhodomaydosoatdifferenttimesandfewcustomersreportwhenthepowerhascomebackon.Thusutilitieshavehadincompleteinformationaboutoutagelocations,resultingindelayedandinefficientresponses.Newdevicesandsystemsmakeitpossibleforutilitiestoknowwhencustomerslosepowerandtopinpointoutagelocationsmoreprecisely.Thiscapabilityimprovesrestorationtimesandshortensoutagedurations.Smartmetersareequippedwithoutagenotificationcapabilitiesthatallowthedevicestotransmitalastgaspalertwhenpowertothemeterislost.Thealertincludesthemeternumber,whichindicatesitslocation,andatimestamp.Advancedmeteringinfrastructure(AMI)headendsystems(HES)processthesealertsandcannotifygridoperatorsandrepaircrewswhichmeterslostpowerandtheirlocations.TheHESisnormallyintegratedwithanOMStoprocessoutagedatafrommultiplesourcesandhelpoperatorstoassessthescopeofoutagesanddeterminetheirlikelycauses.Smartmeterscanalsotransmitpoweronnotificationstooperatorswhenpowerisrestored.ThisinformationcanbeusedtomoreeffectivelymanageservicerestorationeffortsandhelpReliabilityImprovementsInitialResults Page10


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ensurethatnootheroutageshaveoccurredbeforerepaircrewsaredemobilized.SomeutilitiesuseanAMIfeaturethatallowsthemtopingmetersinaffectedareastoassessoutageboundariesandverifywhetherpowerhasbeenrestoredtospecificcustomers.Thesecapabilitiesenablefieldcrewstobedeployedmoreefficiently,thussavingtimeandmoney.2.4 ExpectedBenefitsTherearetwomaintypesofbenefitsfromdeployingsmartgriddevicesandsystemstoaddressdistributionreliabilitychallenges:reliabilityimprovementsandoperationalsavings.ImprovedReliabilityBothsustainedoutagesandmomentaryinterruptionshavethepotentialtonegativelyaffectpublichealthandsafety,economicactivity,andsocietalwellbeing.Fewerinterruptionsforcommercialandindustrialcustomersoftenmeanhigherlevelsofoutputandproductivityandlowerlevelsofscrapandspoilage.Thisaffectstheirfinancialperformanceandabilitytocompete.Thebenefitsoffeweroutagesforresidentialcustomersrangefromgreaterconvenience,tosavingsfromlessfoodspoilage,toavoidanceofmedicalandsafetyproblems.Reducingthefrequencyofoutages,asmeasuredbySAIFIandMAIFI,isgenerallyrelatedtoacombinationoffactorsincludingundergrounding,stormhardening,infrastructureimprovements,andtheuseofautomateddistributionsystems.Forexample,diagnosisandnotificationofequipmentconditionscanpreventequipmentfailureswhileFLISRactionsprimarilyinvolvereductionsinthenumberofcustomersaffectedbysustainedoutages.Thishappenswhenautomatedfeederswitchingisinstalledonafeederandthecircuitisdividedintosections,whichcanreducethecustomersaffectedduringanoutagebyreroutingpowerandprotectingnonaffectedsectionsandthecustomerstheyserve.Reducingoutageduration,asmeasuredbySAIDI,isgenerallyrelatedtotheimplementationofdistributionautomationandmoreefficientoperatingandrestorationpractices.Isolating,reclosing,orFLISRactionscanreduceoutagedurationforcustomersonsectionsoffeedersthatareisolatedfromdamages.Outagedurationsarereducedprimarilyfortworeasons:automatedswitchingeliminatesthetimerequiredtodispatchfieldcrewstomanuallyactuateswitches,andautomatedisolationoftheportionsofthefeederthatarenotdamagedreducethenumberofcustomersaffectedbysustainedoutages.Inaddition,thedurationofoutagescanalsobereducedbyimprovingmethodsforlocatingandaddressingfaults.Reducingthedurationofoutages,asmeasuredbyCAIDI,isgenerallyrelatedtotheimplementationofoutagedetectiontechnologiesandmoreefficientrestorationpracticesforthosecustomersexperiencingsustainedoutages.Remotefaultindicatorsandsmartmeterscan



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beusedtoimproverestorationtimes.Improvedoutagedetectioncapabilitiesreducethetimetoidentifyandlocateoutages.Theyalsoreducethenumberofcustomerswhoexperienceanestedoutageforprolongedperiodsafterothercustomershavehadpowerrestored.Table1providesasummaryofthevarioussmartgridapplicationsforelectricdistributionreliabilityandtheirexpectedimpactsonthefrequencyanddurationofoutages.OperationalSavingsUtilitiesspendsignificantresourceslocatingandrespondingtooutages.TheuseofAMIandsmartmeters,faultdetectiontechnologies,andautomatedcontrolscanhelpimprovetheallocationoffieldresourcestorestorepower.Costreductionsarederivedfromfewertruckrollsandlaborresourcestolocateandtroubleshootoutages.Costlyreworkcanbeavoidedby

SmartGridApplications PrimaryImpactsonOutagesFaultdetectionandautomatedfeederswitching Reductionsinthefrequencyanddurationof

outagesandthenumberofaffectedcustomersDiagnosticandequipmenthealthsensors Reductionsinthefrequencyofoutagesandthe

numberofaffectedcustomersOutagedetectionandnotificationsystems Reductionsinthedurationofoutages

Table1.ApplicationsandImpactsonOutagesusingsmartmeterrestorationnotificationstoensureallcustomershavepowerrestoredbeforedemobilizingfieldcrews.Itisexpectedthatthelevelofsavingsfromtheseactionswillcorrelatewiththesizeoftheoutage.Thegreatestsavingswilloccurduringrestorationfollowingmajoreventsthatrequiremanyfieldcrewsandlongworkperiods,oftenunderextremeconditions.Utilitiesfrequentlyoperateswitchestosupportloadbalancingandtodeenergizefeedersegmentsformaintenance.Beforeautomation,manyoftheseactivitiesrequiredcrewstotraveltomultiplesitesandperformswitchingoperationsmanuallybeforemaintenanceoperationsbegan.Whenthemaintenanceworkwascompleted,manualswitchingwasagainrequiredtoputfeedersbackintotheiroriginalserviceconfigurations.Automatedfeederswitchingcanproduceoperationalsavingsbyeliminatingmanualswitchingandimprovingtheproductivityoffieldcrews.Traditionally,distributionequipmentismaintainedmostlybyvisualinspection,onsitetesting,andrepairsaremadebyfieldcrews.Maintenancemayalsoincludereplacementofpartsorentiredevices.Utilitiesnormallymaintainequipmentonpredeterminedschedulesbasedonmanufacturerguidelines.UtilitiesarenowbeginningtouseequipmenthealthsensorsandassetReliabilityImprovementsInitialResults Page12


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managementsystemstooptimizemaintenanceschedulesandlowercosts.Referredtoasconditionbasedmaintenance,theseprocessesemployequipmenthealthsensors,communicationsnetworks,andadvancedalgorithmstodetermine(1)theconditionofkeyassets,(2)operatingtrendsandthelikelihoodoffailure,and(3)whentonotifyoperatorsandfieldcrewsthatmaintenanceisrequired.Conditionbasedmaintenanceisintendedtodeployresourcesmoreefficientlywhilemaintainingacceptablereliabilityperformancelevels.



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3. SGIGDistributionReliabilityProjectsandDeploymentProgress

The48SGIGprojectsdeployingvariouselectricdistributiontechnologies,tools,andtechniquestoimprovereliabilityarelistedinTable2.AppendixDprovidesfurtherinformationontheseprojectsandthedevicesandsystemstheyhavedeployedasofJune30,2012.Oncetheseprojectsfinishinstallingequipmentandbeginoperations,theyareexpectedtohaveenhancedcapabilitiesforimprovingelectricdistributionreliability.However,mostoftheprojectshavenotfinishedinstallingequipment,andmanyarecurrentlyfocusedontestingandpreparingtobeginoperationsinthenearfuture.

ElectricCooperatives PublicPowerUtilities InvestorOwnedUtilities DentonCountyElectric BurbankWaterandPower, AvistaUtilities,Washington

Cooperative,Texas California CenterPointEnergy,Texas NorthernVirginiaElectric CentralLincolnPeoples ConsolidatedEdisonCompanyof

Cooperative,Virginia UtilityDistrict,Oregon NewYork,Inc.,NewYork GoldenSpreadElectric CityofAnaheimPublic DetroitEdisonCompany,Michigan

Cooperative,Inc.,Texas UtilitiesDepartment, DukeEnergy,Indiana,NorthCarolina, PowderRiverEnergy California Ohio,SouthCarolina

Corporation,Wyoming CityofAuburn,Indiana ElPasoElectric,Texas RappahannockElectric CityofFortCollinsUtilities, FirstEnergyServiceCompany,NewJersey,

Cooperative,Virginia Colorado Ohio,Pennsylvania SouthMississippiElectric CityofGlendale,California FloridaPower&LightCompany,Florida

PowerAssociation, CityofLeesburg,Florida HawaiianElectricCompany,HawaiiMississippi CityofNaperville,Illinois IndianapolisPowerandLightCompany,

SouthwestTransmission CityofRuston,Louisiana IndianaCooperative,Inc.,Arizona CityofTallahassee,Florida MinnesotaPower(Allete),Minnesota

TalquinElectricCooperative, CityofWadsworth,Ohio NSTARElectricCompany,MassachusettsInc.,Florida CumingCountyPublicPower OklahomaGasandElectric,Oklahoma

VermontTransco,LLC, District,Nebraska PECO,PennsylvaniaVermont EPB,Tennessee PotomacElectricPowerCompany

GuamPowerAuthority, AtlanticCityElectricCompany,Guam NewJersey

KnoxvilleUtilitiesBoard, PotomacElectricPowerCompanyTennessee DistrictofColumbia

PublicUtilityDistrictNo.1of PotomacElectricPowerCompanySnohomishCounty, MarylandWashington PPLElectricUtilitiesCorporation,

SacramentoMunicipalUtility PennsylvaniaDistrict,California ProgressEnergyServiceCompany,Florida,

TownofDanvers, NorthCarolinaMassachusetts SouthernCompanyServices,Inc.,

Alabama,Georgia,Louisiana,Mississippi WestarEnergy,Inc.,Kansas

Table2.SGIGProjectsDeployingDistributionReliabilityDevicesandSystemsReliabilityImprovementsInitialResults Page14


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Figure6providesasummarythatshowsthenumberofprojectsthataredeployingvarioustypesofdevicesandsystemstoimprovedistributionreliability.Asshown,thereisarelativelyhighlevelofinterestinautomatedfeederswitches.Manyoftheprojectsaredeployingautomatedswitchesonasmallnumberoffeederstoevaluateequipmentperformancebeforedecidingtoundertakelargescaleinvestmentsindistributionautomationprojects.Severaloftheprojectshavealreadygonethroughthisstepandareinstallingautomatedswitchesonalargenumberoffeeders.AMIoutagedetectioncapabilitiesandremotefaultindicatorsarealsobeingusedinamajorityoftheprojects.

Figure6.NumberofSGIGReliabilityProjectsDeployingCertainDevicesandSystemsFigure7providesabreakdownofthe42projectsthataredeployingautomatedfeederswitchestoshowtherangeinthenumberoffeedersbeingupgraded.Utilitiestypicallyinstallonetothreeswitchesonadistributionfeederdependingontheconfiguration,length,customersserved,andthenumberofdifferentroutes(tiepoints)toalternatepowersources.Asshown,thereareanumberofprojectsdeployingasmallnumberofswitchestotestinteroperabilityandfunctionalitywithcommunicationnetworksandenterprisesystems.Theseprojectsintendtoresolveissuesonspecificfeedersandgenerallyaffectasmallnumberofcustomers.Otherprojectsareinstallinglargenumbersofswitcheswhichaffectreliabilityforspecificregions,butgenerallynotforentiresystems.



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Figure7.NumberofProjectsDeployingAutomatedFeederSwitches3.1 DeploymentProgressFigure8providesanoverviewoftheprogressofprojectsthataredeployingautomatedfeederswitchesasofJune30,2012.Thechartshowsthatabout32%oftheprojectshavecompletedtheinstallationofautomatedfeederswitchesandthatabout30%havenotgottenstartedyet,andtherestaresomewhereinbetween.Intotal,about50%oftheautomatedfeederswitcheshavebeeninstalledbytheprojects.AppendixDprovidesprojectleveldetailsofthedifferentdevicesandsystemsthatarebeingdeployedbythe48projects.Forexample,itlistswhethertheprojectsplantodeploycertaintypesofequipment,whetherornottheyplantointegrateapplicationsorsystems,thedevicesandsystemsbeingdeployedfordiagnosisandnotificationofequipmentconditionsanddetectionofoutages.AppendixDshowsthatthemajorityoftheprojectsaredeployingmultipletypesofdevicesandsystems.



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Figure8.ProgresswithDeployingAutomatedFeederSwitches3.2 ProjectExamplesThefollowingexamplesprovidemorespecificinformationtoillustratehowelectricdistributionreliabilityobjectivesarebeingaccomplishedbySGIGprojects.8Theexamplesexplainthedistributionreliabilityobjectivesthattheprojectsarepursuingandhowthedevicesandsystemsarebeingappliedtoachievethem.CenterPointEnergyHoustonElectric,LLC(CEHE)CEHEisaregulatedtransmissionanddistributioncompanyservingovertwomillionmetereddistributionlevelcustomersina5,000squaremileareaalongtheTexasGulfCoast,includingtheHoustonmetropolitanarea.CEHEispursuingtwoprimaryreliabilityobjectives:(1)reducingthefrequencyofoutagesduetoequipmentfailuresandotherfactorsand(2)restoringservicemorequicklytoreduceoutageduration.Equipmentisbeinginstalledonradialoverheadfeederswithadensityofapproximately151customersperdistributionmile.DMSandmultilayercommunicationssystemsconsistingoffiber,Ethernet,microwave,andwirelessmeshnetworksarebeingintegratedwithAMItoaccomplishtheseobjectives.

8DescriptionsoftheseandotherSGIGprojectsareavailableat:

http://www.smartgrid.gov/recovery_act/deployment_status/project_specific_deployment

http://www.smartgrid.gov/recovery_act/deployment_status/project_specific_deploymenthttp://www.smartgrid.gov/recovery_act/deployment_status/project_specific_deployment


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MonitoringequipmentonsubstationpowertransformerswillbeusedbyCEHEtopreventequipmentfailurescausedbythermaloverloading.TheDMSwillanalyzeequipmenthealthsensordataandprovideoperatorsandrepaircrewswithinformationtorespondtoabnormaloperatingconditions.AdvancedmeteringinfrastructurewillbeusedbyCEHEtotransmitpremiseleveloutageandrestorationnotificationstoCEHEsOMSandDMS.ThesedatawillbeusedinconjunctionwithoutageinformationfromSCADAandcustomercallstodispatchservicecrewstocompleterepairorders.CEHEisautomatingfeedersbyreplacingelectromechanicalrelaypanelswithmicroprocessors,installingautomatedfeederswitches,andretrofittingexistingswitches.ThesedeviceswillbeintegratedwithDMS,whichcompilesinformationfromSCADA,otherdistributionequipment,andsmartmeterstosupportFLISR.Basedonthisinformation,theDMSwillbeabletoremotelyassessoperatingconditionsonthedistributionsystem,locatefaults,andreroutepowerforservicerestoration.CEHEgridoperatorswilloperateswitchesremotelyuntilDMSintegrationandautomatedFLISRareoperationalin2014.EPBLocatedinChattanooga,Tennessee,EPBservesapproximately172,000customers,involvingapproximately309distributionfeedersand117substations.EPBispursuingtwoprimarydistributionreliabilityobjectives:(1)reducingoutagefrequencyand(2)restoringservicemorequicklytoreduceoutageduration.EPBisinstallingnewautomatedfeederswitchesonits46kilovoltand12kilovoltoverheadfeeders.Thesefeedersareacombinationofradialandloopedoverheadfeederswithadensityofapproximately48customersperdistributionmile.Theprojectexpectstorealizetheequipmentsfullpotentialayearafterallequipmentisinstalledandintegrated.EPBhasinstalleddecentralizedautomatedfeederswitchesandcontrolpackageswithfaultinterruptingandreclosingcapabilitiestoisolatefaultsandreroutepowertotheportionsoffeedersthatarenotdamaged.Theimplementationofthisfaultlocating,isolation,andservicerestoration(FLISR)capabilitywillbecompletedin2012.Whiletheswitchesoperateautonomously,operationalandoutagedataaresenttotheSCADAsystemandoperatorscanalsocontroltheswitchesremotely.EPBisalsoimplementingDMSthisyear.Theoverallcommunicationsnetworkfordistributionautomationutilizesavirtuallocalareanetwork(VLAN)onEPBsfiberopticsystem.ThefibernetworkalsoincludesaseparateVLANthatsupportsAMI.EPBhasinstalledthemajorityofitssmartmetersandhasimplementedoutagenotificationcapabilities.EPBisusingAMItoconfirmthatpowerisrestoredtocustomers



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beforedemobilizingrestorationcrews.AMIandanOMSarebeingintegratedattheendofthisyear,andtheprojectisusingoutagenotificationdataforbetterdecisionsupportbygridoperatorsandfieldcrews.PhiladelphiaElectricCompany(PECO)HeadquarteredinPhiladelphia,Pennsylvania,PECOserves1,600,000customers,involvingapproximately2,278distributionfeedersand450distributionsubstations.PECOispursuingtwoprimaryreliabilityobjectives:(1)reducingoutagefrequencyand(2)restoringservicemorequicklytoreduceoutageduration.Automatedloopschemeequipmentisbeinginstalledmostlyonradialoverheadfeederswithacustomerdensityofapproximately73customersperdistributionmile.SomeportionsofPECOsundergroundsystemarealsobeingaddressed.ADMSandfiberopticandwirelesscommunicationsnetworksarebeingintegratedwithnewand

existing

reclosers.

Smart

relays

and

load

monitors

are

being

installed

at

substations

to

detectdisturbancesandisolatefaults.AMIoutagedetectionisalsobeingintegratedwithOMStosupportrestorationactivities.Automatedfeederswitchesareoperatinginadecentralizedmannertoaccomplishreclosing,butwillbeintegratedwithaDMStoaccomplishFLISR.Reclosersisolatefaultsandattempttoclearthefaultbyreclosingafterpreconfiguredintervalsandovercurrentsettings.ReclosingactionsareloggedandcommunicatedtotheOMSsoPECOcananalyzetheimpactonoutagedurationandthenumberofcustomersaffected.



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4. AnalysisofInitialResultsThissectionpresentsanalysisofthefourSGIGprojectsrepresentingfourfeedergroupsthatreportedinitialresultstoDOEOEandincludesresultsthatareaggregatedoverallfourfeedergroupsandalsoanalyzedattheprojectlevel.Observationsbasedontheinitialresultsarealsopresented.AppendixCprovidesmoredetailedanalysisofthefourfeedergroups,whicharelabeledAthroughDtomasktheidentityoftheprojectsbecausethedataisconsideredconfidentialaccordingtothetermsandconditionsofthegrants.TheanalysisresultsincludechangesinthereliabilityindicesthatwerecalculatedbasedondifferencesbetweenbaselineforecastsandmeasuredconditionsfromApril1,2011toMarch31,2012.Thebaselinesweredevelopedbytheprojectsusinghistoricalreliabilitydataforthefeederswhereequipmentwasinstalledandoperational.TheprojectsusedIEEEstandardsforcalculatingbaselinesandexcludeddatafromtimeperiodsthatwereconsideredtobeoutsideofhistoricalaverages.Theinitialanalysisfocusesontheimpactsfromautomatedfeederswitchingandenhancedfaultdetectioncapabilitiesasthiswastheequipmentthatwasinstalledandoperational.Futureanalysiswilladdressothersmartgridcapabilitiesfordistributionreliability.4.1 AggregatedResultsGridoperatorsusedbothdecentralizedandcentralizeddistributionautomationapproachestoisolatefaultsandrestorepowertofeedersegmentsthatwerenotdamaged.Someprojectsusedbothapproacheswithintheirsystembasedonthefeederdesigns,customerdensities,andoutagehistories.Smartmeternotificationswereusedbyoneprojecttoconfirmpowerrestorationsandavoidnestedoutages,butwerenotusedtocoordinateautomatedfeederswitchesortosupportgridoperators.Table3providesinitialresultsoftheimpactsfromtheoperationofthedevicesandsystemsforthefourfeedergroups.Thetableprovidesarangeofresultsbasedonthenumberoffeederswitchesthatwereoperationalduringtheobservationperiod.Therangesincludelowandhighpercentchangesinthereliabilityindicesfromthecorrespondingbaselines.Thebaselinevaluesarealsolistedtoprovidereferencepointsofthehistoricalreliabilitylevels.OnlyoneprojecttrackedMAIFIandreportedresultsinthisarea.Theresultsshowsignificantimprovementinreducingsustainedinterruptions,momentaryinterruptions,andaveragesysteminterruptiondurationascalculatedbychangesinSAIFI,MAIFI,andSAIDIrespectively.(SeeAppendixAfordefinitionsoftheseindicesandequations



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showinghowtheyarecalculated.)Thegreatestimprovementsintheseindicesoccurforthefeedergroupswiththeworstbaselinereliabilitylevels.Alsoshowninthetableisanadditionalindexusedforassessingreliabilityimpacts,CustomerMinutesInterrupted(CMI),thatmeasuresthetotalnumberofcustomersandtheminutestheywerewithoutpower.AsshowninAppendixA,CMIisoneoftheinputsusedtocalculateSAIDI.Table3alsoshowsthataveragecustomerinterruptiondurationindex(CAIDI)worsenedinmostcases,despitethefactthattheextentofsustainedoutageswasreducedbyautomatedfeederswitching.ThisisduelargelytothetermsoftheequationthatisusedtocalculateCAIDI.Forexample,asthenumberofcustomersexperiencingsustainedoutagesisreduced,thedenominatoroftheCAIDIindexalsogoesdownrelativetothevalueofthenumerator,andthustheoverallindexincreases.ReducingCAIDIrequiresreducingrestorationtimesforthoseremainingwithoutpowerafterautomatedfeederswitchingoperationshaveoccurred.Itisexpectedthatenhancedfaultdetectionandoutagedetectionandnotificationcapabilitieswillcontributetoreductionsinthedurationofsustainedoutagesforaffectedcustomers,andthusreduceCAIDI.ReliabilityIndices Units RangeofImprovement%Change(LowtoHigh) RangeofBaselines(LowtoHigh)

SAIFI AverageNumberofSustainedInterruptions 13%to 40% 0.8to1.07

MAIFI AverageNumberofMomentaryInterruptions 28% 9.0

SAIDI AverageNumberofSystemOutageMinutes 2%to 43% 67to107

CAIDI AverageNumberofCustomerOutageMinutes +28%to 2% 67to100

CMI TotalNumberofCustomerMinutesInterrupted(Millions) +8%to 35% 44to20

Table3.SummaryofChangesinDistributionReliability(April

2011March

2012)

4.2 FeederGroupSpecificResultsFigure9showsthechangesinreliabilityforthefourfeedergroupsA,B,C,andD.Outagefrequency(SAIFI)isgivenonthehorizontalaxisandcustomeroutageduration(CAIDI)isshown



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ontheverticalaxis.Curvesrepresentativeofsystemoutageduration(SAIDI)areheldconstanttoshowtherelationshipbetweenCAIDI,SAIFI,andCMI.Thefiguredepictsthereliabilitychangesbythemovementfromthebaseline(solidcircles)tothemeasuredresults(opencircles).Asshowninthefigure,reliabilityimprovementsoccurfromfewerandshorteroutages,whichonthechartareshownbychangestotheleftand/ordown.Thechangeinthesizeofthecirclesrepresentsthechangeinthenumbercustomerminutesinterrupted(CMI).Thefigureshowsthatalloftheprojectsareimprovingreliabilitybyreducingthefrequencyanddurationofsustainedoutages.Thisreductionisattributabletotheoperationofautomatedfeederswitchestoisolatefaultsandrestorepowerresultinginareductioninthenumberofcustomersexperiencingsustainedoutages.FeedergroupAattributedaportionoftheimprovementstotheuseofequipmenthealthsensorstopreventoverloadingofpowertransformerswhichwouldhaveresultedinasignificantoutageonmultiplefeeders.

Figure9.ProjectLevelChangesinDistributionReliability(April2011March2012)FeedergroupsA,C,andDshowCAIDIgettingworsewhileSAIDIisgettingbetter.Asdiscussedpreviously,reductionsinCAIDIwillbeimprovedasthetimetorestorepowertothoseremainingwithoutpoweritisreduced.



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FeedergroupB,ontheotherhand,showedCAIDIimprovements,buttheydidnotattributetheimprovementstothedeploymentofsmartgridequipmentbutrathertothetypesofoutagesthatoccurredandtheconvenientlocationofthefeederandtheabilityoffieldcrewstorestorepowerrelativelyquickly.Withtheapplicationofoutagedetectionandnotificationsystems,andcorrespondingimprovementsinservicerestorationpractices,thedurationofoutagesexperiencedbyaffectedcustomersonallfeedersandlocationscandecrease,andthusCAIDIcanbeexpectedtodecrease.Ingeneral,reliabilityimprovedoverallbecauseofreductionsinSAIFIandSAIDI.TheprojectsexpectthatimprovementsinoutagefrequencyandCMItocontinueasmoreswitchesareinstalledandgridoperatorsgainexperiencedevelopingautomationschemesanddevelopingactionableinformationfromfaultdetectiondevicesandequipmenthealthsensors.4.3 SummaryofObservationsAsdiscussed,mostoftheprojectsthathavereportedinitialresultsarestillinstallingequipment,integratingsystems,andrefiningapproachestoachievetheirrespectivedistributionreliabilityobjectives.Whileimpactshavebeenobserved,manyaretheresultofdeploymentsandintegrationeffortsthatarenotcomplete.Becausetheprojectshavedifferentlevelsofexperiencewiththevariousautomationapproaches,theyhaveindicatedthatthereisasignificantlearningperiodforgridoperatorsandfieldcrewstounderstandthenewdevicesandsystemsanddeterminethebestwaystousethemtoachievedesiredresults.Ingeneral,thecompanieswiththemostpriorexperiencehavebeentheonesmostabletoachievebetterresults.Theprojectshavebeenabletoattributereductionsinthefrequencyanddurationofoutagestotheinstallationandoperationoffaultdetectionandautomatedfeederswitchingequipment.Ingeneral,theseprojectsreportthattheyhaverelativelyhighconfidencelevelsintheinitialresultsandhaveconfirmedinformationonspecificoutagesandswitchingoperationstosupporttheirpreliminaryfindings.OneofthecontributingfactorstotheobservedreductioninthefrequencyofsustainedoutagesistheprocessofrepairingwornordamagedequipmentaspartoftheoverallinstallationprocesswhendeployingtheSGIGequipment.Thesepracticeshavecontributedtothereliabilityimprovementsobservedherebutarenotrelatedtotheoperationofthenewdevicesandsystems.Thereisarelativelyhighlevelofvariationinthereportedresults.Someofthisisduetothevariationsindevicesandsystemsbeinginstalledandtovariationsinthelevelsofexperiencewithoperatingautomateddistributiondevicesandsystems.ThereisalearningperiodduringReliabilityImprovementsInitialResults Page23


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whichgridoperatorsandfieldcrewsbecomeacquaintedwithfunctions,capabilities,andstrategiesforoperatingautomatedfeederswitchestoachieveperformanceimprovementsanddevelopneededcompetencies.Inaddition,differencesinbaselinesalsocontributetothevariabilityofresults.TheinitialresultsalsoindicateaneedtomonitortheimpactsofautomatedfeederswitchingonCAIDIovertimetoassessitsusefulnessasareliabilityindex.ThisisbecauseincreasesinCAIDIdonotnecessarilyindicatethatreliabilityisgettingworse.Infact,becauseofautomatedfeederswitchingfewercustomersareexperiencingsustainedoutages,andthereforereliabilityisgettingbetter.ImprovementsinCAIDIcanbeachievedwithotherapproachessuchasadvancementsinoutagedetectionandnotificationandimplementationofimprovementsinservicerestorationpractices.Mostutilitiesdonottrackthefrequencyofmomentaryinterruptions,and/ortheydonothavesufficienthistoricaldatatodevelopappropriatebaselines.Projectsmaynothavethedatameasurementsystemsinplace,ortheymaynotberequiredtoprovidethisinformationtoregulators.However,thedeploymentofsmartdevicesandsystemsprovidetheprojectswithnewandbetterwaystoassessmomentaryinterruptions.Someprojectsreportthattheyplantousethesedatatoidentifyfeedersthathavehighfrequenciesofmomentaryinterruptions,andthattheywillfollowupanddomoreinspectionsofthesefeedersegments,andwilltakecorrectiveactions,suchasvegetationmanagement,toavoidmomentaryinterruptions(andsustainedoutages)inthefuture.



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5. NextStepsAsadditionaldataontheimpactsbecomeavailable,DOEOEwillconductfurtheranalysisoftheresults.CollaborationbetweenDOEOEandtheSGIGdistributionreliabilityprojectsisessentialforensuringthatappropriatedataaregatheredandreported,andforunderstandingtheanalysisresults.Collaborationincludesreviewsofresultswiththeappropriateprojectteamstovalidatethemandsharewhathasbeenlearned.Theanalysishasfocusedsofaronchangesinreliabilityindicesbutwillbeexpandedasmoreprojectscompleteequipmentdeploymentandbegintointegratethenewdevicesandsystemswithdistributionsystemoperations.Forexample,DOEOEplanstoexpandtheanalysistounderstandtheroleofdistributionreliabilitydevicesandsystemsinreducingrestorationandoperationsandmaintenancecosts.Dependingontheavailabilityandqualityofquantitativedatafromtheprojects,potentialareasforfutureanalysisinclude:understandingtheincrementalimpactofsmartmeterswhenworkingtogetherwithdistributionautomationsystems,analyzingresultsoverextendedtimeperiodstoidentifytrendsandchangesastheyrelatetoincreasedoperationalexperience,trackingtheoperationofautomatedfeederswitchingequipmenttobetterdeterminecustomersaffectedandoutagedurationimpacts,andassessingtheintegrationofDMSwithexistingandnewdevicesandsystemsandtheeffectsofrefinedrestorationalgorithmsonreliabilitylevels.TheSGIGprojectsincludingthefourdiscussedinthisreportwillcontinuetoimplementdistributionreliabilitydevicesandsystemsandreportactivitiesandresults.DOEOEplanstopresentadditionalresultsandlessonslearnedfromtheSGIGdistributionreliabilityprojectsinthefuture.Inthemeantime,updatesondeploymentprogressandcasestudieshighlightingprojectexamplesarepostedregularlyonwww.smartgrid.gov.



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ReliabilityImprovementsInitialResults PageA1

AppendixA.ReliabilityIndicesReliabilityIndex EquationDescription Equation

Thesumofthenumberofinterrupted

customers(Ni)foreachpoweroutagegreaterSystemAverage

thanfiveminutesduringagivenperiod,orInterruption Ni CIcustomersinterrupted(CI),dividedbythetotal SAIFI = =FrequencyIndex

numberofcustomersserved(NT).Thismetricis NT NT(SAIFI)expressedintheaveragenumberofoutagesper

year.Majoreventsareexcluded.

Thesumoftherestorationtimeforeach

sustainedinterruption(ri)multipliedbythesumSystemAverage

ofthenumberofcustomersinterrupted(Ni),orInterruption riNi CMIcustomerminutesinterrupted(CMI),dividedby SAIDI = =DurationIndexthetotalnumberofcustomersservedforthe NT NT(SAIDI)area(NT).Thismetricisexpressedinaverage

minutesperyear.Majoreventsareexcluded.

Thesumoftherestorationtimeforeach

Customer sustainedinterruption(ri)multipliedbythesumAverage ofthenumberofcustomersinterrupted(Ni),or riNi CMI

CAIDI = =Interruption customerminutesinterrupted(CMI),dividedby

Ni NiDurationIndex thesumofthenumberofcustomersinterrupted(CAIDI) (Ni).Thismetriciscommonlyexpressedin

minutesperoutage.Majoreventsareexcluded.

Thesumofthenumberofmomentary

Momentary interruptions(IMi)multipliedbythesumoftheAverage numberofcustomersinterruptedforeach

IMiNmiInterruption momentaryinterruption(Nmi)dividedbythe MAIFI =FrequencyIndex totalnumberofcustomersserved(NT).This NT(MAIFI) metricisexpressedinmomentaryinterruptions

peryear.


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2005to2010IEEESAIFIBenchmarkingQuartiles2

Outages

1.711.8 1.71.63 1.6

Sustained1.6 1.49 1.46

1.39 1.36 1.33 1.341.4

1.171.09 1.11 1.121.2 1.06 1.06

of

Number 0.93

1 0.890.8

Average

0.60.4

FourthQuartileThirdQuartileSecondQuartile

2005 2006 2007 2008 2009 2010

FigureB1.SummaryofIEEEBenchmarkDataSAIFI


AppendixB.IEEEReliabilityBenchmarkDataSince2003,theIEEEDistributionWorkingGrouphassurveyedCanadianandU.S.electricutilitieseachyeartodevelopbenchmarkdataondistributionreliability.Benchmarkdataareprovidedbymorethan100utilities;coveralltypes,sizes,andregions;andareintendedtoprovideinformationsothatutilitiescanassesstheirperformancerelativetooneanother.FiguresB1,B2,andB3provideasixyearsummaryofthedifferentperformancelevelsforSAIFI,SAIDI,andCAIDIandshowthevariabilityamongutilitiesandovertime.ThebenchmarkswerecalculatedusingtheIEEEGuideforElectricPowerDistributionReliabilityIndicesIEEEStandard1366TM2003.Thelinesonthechartsrepresenttheminimumvaluesfortherespectivequartiles.Additionalinformationonthesurveyandlinkstodetailedresultsforeachyearislistedathttp://grouper.ieee.org/groups/td/dist/sd/doc/.

ReliabilityImprovementsInitialResults PageB1
http://grouper.ieee.org/groups/td/dist/sd/dochttp://grouper.ieee.org/groups/td/dist/sd/doc


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2005to2010IEEESAIDIBenchmarkingQuartiles250

Min

utes

200

Outage150

Sustained

198 200192 196167

154 158145 146 143128 FourthQuartile

116105 109 10398

89 ThirdQuartile100 81

SecondQuartile500

2005 2006 2007 2008 2009 2010

FigureB2.SummaryofIEEEBenchmarkDataSAIDI

Minutes

Outa

ge

Customer

Sustained

2005to2010IEEECAIDIBenchmarkingQuartiles160140120100

135131

127 127121 122

108 109 110105 10610294

88 FourthQuartile83 8582 83

ThirdQuartile80

SecondQuartile604020

2005 2006 2007 2008 2009 2010

FigureB3.SummaryofIEEEBenchmarkDataCAIDI


ThesefiguresshowthatmanyU.S.utilitiesaremonitoringchangesinreliabilitylevelsusingtheEEEcalculationstodeterminereliabilityindices,andthattheyaredevelopingbenchmarksIagainstwhichtheycanevaluateandcomparetheirperformance.TheSGIGelectricdistributionreliabilityprojectsareusingcomparableapproachesindevelopingbaselinesforthefeedergroupsanalyzedinthisreport.ReliabilityImprovementsInitialResults PageB2


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AppendixC.SupplementaryAnalysisResultsTablesC1throughC4providetabularresultsforeachofthefourfeedergroupsanalyzedinSection4andarelabeledAthroughDtomasktheidentityoftheprojects.Eachfeedergroupcomprisesasetoffeedersthathavebeenupgradedbytheprojects.Thefourfeedergroupscorrespondtothefourprojects.Thefeedergroupsincludebothloopedandradialfeederconfigurations.FeederGroupATableC1providesinitialresultsforFeederGroupA,whichconsistsof120feeders.Forthisproject,gridoperatorsreportedhavingpriorexperiencedeployingandoperatingautomatedfeederswitchingequipmentandindicatedthattheinitialresultswereinlinewiththeirexpectations.

GridoperatorsattributeimprovementsinSAIFIandMAIFItotheoperationofdecentralizedautomatedfeederswitchingandreclosing.Theoperatorsalsoindicatethatsomeoftheimpactsonoutagefrequencies,includingMAIFI,arerelatedtotheinspectionandrepairofwornfeedersthatoccurredatthesametimeastheinstallationoftheSGIGequipment.TheoperatorsreportthatimprovementsinSAIDIandCMIarealsoprimarilyrelatedtoautomatedfeederswitching.Faultdetectioncapabilities,derivedfromsmartrelaysandDMS,wereusedtosupportsomeoftherestorations.ThemajorityoftheSAIDIandCMIimpactsweresaidtobeduetoreductionsinthenumberofcustomersaffectedbyautomatedfeederswitchingandreclosing.AMIoutagedetectionwasnotoperational,butitisplannedforimplementationinthenearfuture.TheoperatorsindicatedthatincreasesinCAIDIwereduetotheCAIDIcalculationmethod.Theautomatedfeederswitchesreducedthenumberofcustomersaffectedbysustainedoutages.

Index Units April2011September2011 October2011March2012Baseline % Baseline %

SAIFI NumberofInterruptions 1.0 41% 0.6 31%MAIFI NumberofInterruptions 12.6 35% 5.5 13%SAIDI NumberofMinutes 72.3 25% 37.0 11%CAIDI NumberofMinutes 70.4 +27% 63.3 +29%CMI NumberofCustomerMinutes

(Millions) 8.5 25% 6.9 11%TableC1.FeederGroupAResults

ReliabilityImprovementsInitialResults PageC1


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FeederGroupBTableC2providesinitialresultsforFeederGroupB,whichconsistsofapproximately95overheadradialdistributionfeederswithtiepointsinthefirstreportingperiod,and185duringthesecond.GridoperatorsforFeederGroupBreportedhavingpriorexperiencedeployingandoperatingautomationdevicesandsystemsandSCADAsystemsbutindicatedthatthefullcapabilitiesoftheequipmenthadnotyetbeenimplemented.Theoperatorsalsonotedthatweathervariabilitycontributedtoreliabilityimprovements,inadditiontoautomatedfeederswitching,whencomparedtothebaselines.TheoperatorsforFeederGroupBindicatedthatimprovementsinSAIFIwererelatedtotheoperationofcentralizedremotefeederswitchinganddistributedreclosing.Switchingenabledoperatorstoavoidsustainedoutagesforportionsofthefeederthatwerenotdamaged.ImprovementsinSAIDIandCMIwerealsosaidtoberelatedtoremotefeederswitchingandreclosing.Themajorityofthefeederswitcheswerecapableofremoteoperations,butadditionalintegrationandengineeringworkisrequiredbeforeFLISRisfullyoperational.TheoperatorsreportedanincreaseinCAIDIduringthefirstreportingperiodandadecreaseduringthesecond.TheysaidthedecreasesinCAIDIweretheresultofafeedersegmentthathappenedtoberelativelyeasytorepair.


SAIFI

Numberof

Interruptions

1.3

41%

0.8

49%

MAIFI NumberofInterruptions SAIDI NumberofMinutes 133.2 35% 79.8 56%CAIDI NumberofMinutes 99.6 +11% 100.0 15%CMI NumberofCustomerMinutes

(Millions) 20.4 35% 22.6 56%

TableC2.FeederGroupBResults

FeederGroupCTableC3providesinitialresultsforFeederGroupC,whichconsistsofapproximately285overheaddistributionfeederswithtiepointsinthefirstreportingperiodand870inthesecond.Thegridoperatorsreportedhavinglittlepriorexperiencedeployingandoperatingremotefeederswitchesandfaultlocationanalysistoolsandtheysaidtheydonotbelievetheyhaverealizedthefullpotentialofthedevicesandsystemsyet.



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TheoperatorsreportedthatimprovementsinSAIFIwererelatedtotheoperationofcentralizedremotefeederswitchingandreclosing.DistributionfeederswerealsoinspectedbeforetheSGIGequipmentwasinstalled.Portionsofthefeederthatwereoutofspecificationordamagedwereidentifiedandrepaired.Examplesincludevegetationmanagement,fusereplacement,andcrossarmreplacement.Theoperatorsindicatedthatsomedeviceswerenotfullyoperationalduringthefirstreportingperiodandthattheyweregainingexperiencewiththeequipmentandfaultlocationanalysistools,includingDMS.Theysaidthatthelackofexperiencecontributedtomeasuredincreasesinthedurationofcustomeroutages.Theoperatorsreporteddecreasesinoutagefrequencyanddurationforthesecondperiod,whichtheyattributedtofeederswitching,relays,andbetteruseofanalysistools.Switchingenabledtheoperatorstoavoidsustainedoutagesforportionsofthefeederthatwerenotdamaged.


SAIFI NumberofInterruptions 1.1 20% 0.6 11%MAIFI NumberofInterruptions SAIDI NumberofMinutes 84.2 +4% 49.2 13%CAIDI NumberofMinutes 80.0 +29% 84.1 2%CMI NumberofCustomerMinutes

(Millions) 48.8 +8% 46.4 9%

TableC3.FeederGroupCResultsFeederGroupDTableC4providesinitialresultsforFeederGroupD,whichconsistsofapproximately75overheadloopedfeeders.Gridoperatorsattributedreductionsinthefrequencyofsustainedoutagestoreclosingandremotebreakerswitching.ReductionsinSAIDIandCMIwerealsoattributedtoreclosingandswitching.Theoperatorsplantoimplementfeederswitchingtoreroutepowerfromalternatesources

using

aDMS,

but

this

functionality

was

not

operational

during

the

reporting

periods.

AMIoutagedetectioncapabilitieswerealsonotoperationalorintegratedwiththeOMSduringthereportingperiods.Operatorsanticipateadditionalbenefitswhenthesefunctionsandcapabilitiesarefullyoperational.



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SAIFI NumberofInterruptions 1.5 22% 1.5 24%MAIFI NumberofInterruptions SAIDI NumberofMinutes 139.7 14% 139.7 16%CAIDI NumberofMinutes 97.0 +10% 97.0 +11%CMI NumberofCustomerMinutes

(Millions) 19.0 14% 19.2 16%

TableC4.FeederGroupDResults



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U.S.Depa

AppendixD.SGIGElectricDistributionReliabilityProjects

Project AutomatedFeederSwitchesDevicesDeployedasof6/30/2012

Installed(#) Expected(#) Installed(%)

EquipmentHealthSensors

LoadMonitors

RemoteFault

IndicatorsSmartRelays FLISR AMIOutageDetection

AvistaUtilities 258 258 100% N/A 102 N/A 102 X N/ABurbankWaterandPower N/A N/A N/A 0 N/A 0 74 X X*CenterPointEnergy 204 584 35% 0 0 0 155 X X*CentralLincolnPeople'sUtilityDistrict 0 17 0% 7 0 0 0 X X*CityofAnaheim,California 17 70 24% N/A 0 14 N/A X XCityofAuburn,Indiana 0 13 0% 0 0 0 20 X X*CityofFortCollinsUtilities 0 5 0% N/A 0 0 N/A X X*CityofGlendale,California 4 18 22% N/A 0 0 4 X X*CityofLeesburg,Florida 0 12 0% 0 0 0 0 X XCityofNaperville,Illinois 7 7 100% N/A 0 0 12 X* X*CityofRuston,Louisiana 0 10 0% N/A N/A 0 N/A X X*CityofTallahassee,Florida 0 75 0% N/A N/A 0 N/A X N/ACityofWadsworth,Ohio 0 24 0% 0 0 0 0 X X*ConsolidatedEdisonCompanyofNewYork,Inc. 572 630 91% 11,170 274 381 61 X N/ACumingCountyPublicPowerDistrict 0 9 0% N/A 67 N/A N/A N/A N/A

ReliabilityImprovementsInitialResults


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U.S.Depa




LoadMonitors

RemoteFault


DentonCountyElectricCooperative 2 2 100% N/A N/A 6 N/A X XDetroitEdisonCompany 5 121 4% 2 N/A N/A 31 X X*DukeEnergy 387 416 93% N/A 49 219 251 X* XElPasoElectric 13 13 100% N/A 6 8 8 X* N/AEPB 1,124 1,300 86% N/A 0 0 0 X X*FirstEnergyServiceCorporation 0 30 0% N/A 0 N/A 0 X N/AFloridaPower&LightCompany 230 254 91% 2,452 108 159 863 X* XGoldenSpreadElectricCooperative,Inc. 0 121 0% 0 N/A N/A N/A X X*GuamPowerAuthority 0 34 0% 0 N/A 0 0 X XHawaiianElectricCompany 29 29 100% N/A N/A N/A N/A N/A N/AIndianapolisPower&LightCompany 158 178 89% 0 N/A 0 435 N/A XKnoxvilleUtilitiesBoard N/A N/A N/A N/A N/A 0 N/A N/A X*MinnesotaPower 1 6 17% 0 1 N/A N/A X X*NorthernVirginiaElectricCooperative 10 14 71% 33 N/A N/A 19 N/A N/ANSTARElectricCompany 254 295 86% N/A 254 254 N/A X* N/AOklahomaGas&Electric 69 125 55% N/A N/A N/A 8 X X*PECO 100 100 100% N/A N/A 0 209 X XPotomacElectricPowerCompanyAtlanticCityElectricCompany 146 146 100% 11 N/A N/A 30 X N/A



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U.S.Depa




LoadMonitors

RemoteFault


PotomacElectricPowerCompanyDistrictofColumbia 38 51 75% 14 N/A N/A 354 X X*PotomacElectricPowerCompanyMaryland 67 94 71% 8 N/A 65 306 X X*PowderRiverEnergyCorporation N/A N/A N/A N/A N/A N/A N/A N/A N/APPLElectricUtilitiesCorporation 213 213 100% N/A N/A 0 0 X XProgressEnergyServiceCompany 218 440 50% 24 1,425 N/A N/A X XPublicUtilityDistrictNo.1ofSnohomishCounty 0 31 0% N/A 11 11 281 X N/ARappahannockElectricCooperative N/A N/A N/A N/A 23 N/A N/A N/A X*SacramentoMunicipalUtilityDistrict 2 153 1% N/A 0 0 97 X X*SouthMississippiElectricPowerAssociation N/A N/A N/A 5 28 0 39 N/A X*SouthernCompanyServices,Inc. 1,537 2,059 75% 109 N/A 62 739 X* X*SouthwestTransmissionCooperative,Inc. 12 12 100% 99 0 54 92 X X*TalquinElectricCooperative N/A N/A N/A N/A N/A N/A N/A N/A X*TownofDanvers,Massachusetts

4 45 9% N/A 1 N/A 0 X X*VermontTransco,LLC 23 144 16% 7 23 13 151 N/A X*WestarEnergy,Inc. 31 31 100% N/A N/A 27 N/A X X*



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AppendixE.OverviewofFeederSwitchingOperationsAutomatedfeederswitchesarebecomingkeycomponentsinelectricdistributionsystems.Thesedevicescanbeopenedorclosedinresponsetosensingafaultcondition,orbyreceivingcontrolsignalsfromotherlocations.FiguresE1andE2showhowthiscanbeaccomplished.

Smart Switch Smart Switch(Normally Open) (Normally Closed)

A

A B

C

B

BA

B

C

C

Customers

served bySubstation A Substation A Substation B

Smart Switch(Normally Open)

A

Customers

served bySubstation B

B

Fault

Substation C

FigureE1.ConfigurationofFeederBeforeSwitchingCustomers

now served bySubstation C

A

A B

C

A B

CA

C

C

C

Fault

B

FigureE2.ConfigurationofFeederAfterSwitching

ReliabilityImprovementsInitialResults PageE1


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Ingeneral,therearethreemajortypesoffeederconfigurationsthataredeployedbyutilities:(1)radialfeeders,(2)loopedfeeders,and(3)networkedfeeders.Utilitiestypicallyemployradialfeedersforremoteareaswherepopulationdensitiesarerelativelylow.Loopedandnetworkedfeedersaremostsuitableformoredenselypopulatedareas.RadialFeedersRadialfeedersoriginateatsubstations,servegroupsofcustomers,andarenotconnectedtoanyotherfeeder.Powerflowsalongradialfeedersfromsubstationstocustomersalongasinglepath,which,wheninterrupted,resultsinlossofpowertothecustomersservedbythosefeeders.Radialfeedersaretypicallyconnectedtoasinglesubstationandcannotbefedfromothersources.FigureE3illustratesatypicalswitchingsequenceforradialfeeders.Inthisexample,thenumberofcustomerswhoexperiencesoutagescanbereducedbyoperatingaswitchonthefeeder.

1

Fault

2

Fault

3

Fault

4

CircuitSwitch(closed) SubstationtransformerLinetransformer

PrimaryfeederLateralcircuitFuse

CircuitSwitch(open)Note:Deenergizedportionofthecircuitandloadswithoutpowerarehighlightedinred.

FigureE3.ExampleofSwitchingOperationsonRadialFeedersReliabilityImprovementsInitialResults PageE2


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LoopedFeedersLoopedfeedersinvolveatleasttwofeedersinterconnectedthroughnormallyopentiepoints(i.e.,undernormalconditions,electricitydoesnotflowthroughthetiepoint).Powercanflowonloopedfeedersfromalternatepathsduringoutages.FigureE4illustratesswitchingoperationsonloopedfeedersandshowshowutilitiescanreducetheimpactsoffaultsbyquicklyisolatingthem.

1

Fault

2

Fault

3

CircuitSwitch(closed)

Substationtransformer

Linetransformer

PrimaryfeederLateralcircuitFuse

CircuitSwitch(open)

Note:Deenergizedportionofthecircuitandloadswithoutpowerarehighlightedinred.

Directionofpower flow

FigureE4.ExampleofSwitchingOperationsonLoopedFeedersNetworkedFeedersNetworkedfeedersinvolvemultiplepowerflowsfrommultiplesourcestoallofthecustomersthatareservedbythenetwork.Ifafailureoccursinoneofthelines,powercanbereroutedinstantlyandautomaticallythroughotherpathways.Forexample,ifonesourceisinterruptedduetoafaultedsegment,thecustomerisautomaticallytransferredtoanothersource.FigureE5illustratesswitchingoperationsonnetworkedfeederstoreducetheimpactsofoutages.

ReliabilityImprovementsInitialResults PageE3


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PrimaryDisconnect

SecondaryDisconnect

1 2

Fault

3

Fault

4Fault

FigureE5.ExampleofSwitchingOperationsonNetworkedFeeders

distribution reliability report - final (1).pdf

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