10/12/2014 AdvantagesOfIEC61850|EEP

http://electricalengineeringportal.com/advantagesofiec61850 1/5

electricalengineeringportal.com http://electricalengineeringportal.com/advantagesofiec61850

AdvantagesOfIEC61850

IEC61850AdvantagesandKeyFeatures

Oneofthesignificantchallengesthatsubstationengineersfaceisjustifyingsubstationautomationinvestments.Thepositiveimpactsthatautomationhasonoperatingcosts,increasedpowerquality,andreducedoutageresponsearewellknown.Butlittleattentionispaidtohowtheuseofacommunicationstandardimpactsthecosttobuildandoperatethesubstation.

Legacycommunicationprotocolsweretypicallydevelopedwiththedualobjectiveofprovidingthenecessaryfunctionsrequiredbyelectricpowersystemswhileminimizingthenumberofbytesthatwereusedbytheprotocolbecauseofseverebandwidthlimitationsthatweretypicaloftheseriallinktechnologyavailable10

10/12/2014 AdvantagesOfIEC61850|EEP

http://electricalengineeringportal.com/advantagesofiec61850 2/5

15yearsagowhenmanyoftheseprotocolswereinitiallydeveloped.

Later,asEthernetandmodernnetworkingprotocolslikeTCP/IPbecamewidespread,theselegacyprotocolswereadaptedtorunoverTCP/IPEthernet.

Thisapproachprovidedthesamebasicelectricpowersystemcapabilitiesastheseriallinkversionwhilebringingtheadvantagesofmodernnetworkingtechnologiestothesubstation.Butthisapproachhasafundamentalflaw:theprotocolsbeingusedwerestilldesignedtominimizethebytesonthewireanddonottakeadvantageofthevastincreaseinbandwidththatmodernnetworkingtechnologiesdeliverbyprovidingahigherleveloffunctionalitythatcansignificantlyreducetheimplementationandoperationalcostsofsubstationautomation.

Top

ModernNetworkingTechnologiesIEC61850isunique.IEC61850isnotaformerseriallinkprotocolrecastontoTCP/IPEthernet.IEC61850wasdesignedfromthegrounduptooperateovermodernnetworkingtechnologiesanddeliversanunprecedentedamountoffunctionalitythatissimplynotavailablefromlegacycommunicationsprotocols.

TheseuniquecharacteristicsofIEC61850haveadirectandpositiveimpactonthecosttodesign,build,install,commission,andoperatepowersystems.WhilelegacyprotocolsonEthernetenablethesubstationengineertodoexactlythesamethingthatwasdone1015yearsagousingEthernet,IEC61850enablesfundamentalimprovementsinthesubstationautomationprocessthatissimplynotpossiblewithalegacyapproach,withorwithoutTCP/IPEthernet.

TobetterunderstandthespecificbenefitswewillfirstexaminesomeofthekeyfeaturesandcapabilitiesofIEC61850andthenexplainhowtheseresultinsignificantbenefitsthatcannotbeachievedwiththelegacyapproach.

Top

KeyFeatures

ThefeaturesandcharacteristicsofIEC61850thatenableuniqueadvantagesaresonumerousthattheycannotpracticallybelistedhere.Someofthesecharacteristicsareseeminglysmallbutyetcanhaveatremendousimpactonsubstationautomationsystems.

Forinstance,theuseofVLANsandpriorityflagsforGOOSEandSMVenablemuchmoreintelligentuseofEthernetswitchesthatinandofitselfcandeliversignificantbenefitstousersthatarentavailablewithotherapproaches.Forthesakeofbrevity,wewilllistheresomeofthemorekeyfeaturesthatprovidesignificantbenefitstousers:

UseofaVirtualizedModelThevirtualizedmodeloflogicaldevices,logicalnodes,ACSI,andCDCsenablesdefinitionofthedata,services,andbehaviorofdevicestobedefinedinadditiontotheprotocolsthatareusedtodefinehowthedataistransmittedoverthenetwork.

UseofNamesforAllDataEveryelementofIEC61850dataisnamedusingdescriptivestringstodescribethedata.Legacyprotocols,ontheotherhand,tendtoidentifydatabystoragelocationanduseindexnumbers,registernumbersandtheliketodescribedata.

AllObjectNamesareStandardizedandDefinedinaPowerSystemContext

10/12/2014 AdvantagesOfIEC61850|EEP

http://electricalengineeringportal.com/advantagesofiec61850 3/5

ThenamesofthedataintheIEC61850devicearenotdictatedbythedevicevendororconfiguredbytheuser.Allnamesaredefinedinthestandardandprovidedinapowersystemcontextthatenablestheengineertoimmediatelyidentifythemeaningofdatawithouthavingtodefinemappingsthatrelateindexnumbersandregisternumberstopowersystemdatalikevoltageandcurrent.

DevicesareSelfDescribingClientapplicationsthatcommunicatewithIEC61850devicesareabletodownloadthedescriptionofallthedatasupportedbythedevicefromthedevicewithoutanymanualconfigurationofdataobjectsornames.

HighLevelServicesACSIsupportsawidevarietyofservicesthatfarexceedswhatisavailableinthetypicallegacyprotocol.GOOSE,GSSE,SMV,andlogsarejustafewoftheuniquecapabilitiesofIEC61850.

StandardizedConfigurationLanguageSCLenablestheconfigurationofadeviceanditsroleinthepowersystemtobepreciselydefinedusingXMLfiles.

Top

MajorBenefits

ThefeaturesdescribedaboveforIEC61850deliversubstantialbenefitstousersthatunderstandandtakeadvantageofthem.RatherthansimplyapproachinganIEC61850basedsysteminthesamewayasanyothersystem,auserthatunderstandsandtakesadvantageoftheuniquecapabilitieswillrealizesignificantbenefitsthatarenotavailableusinglegacyapproaches.

EliminateProcurementAmbiguity

NotonlycanSCLbeusedtoconfiguredevicesandpowersystems,SCLcanalsobeusedtopreciselydefineuserrequirementforsubstationsanddevices.UsingSCLausercanspecifyexactlyandunambiguouslywhatisexpectedtobeprovidedineachdevicethatisnotsubjecttomisinterpretationbysuppliers.

LowerInstallationCost

IEC61850enablesdevicestoquicklyexchangedataandstatususingGOOSEandGSSEoverthestationLANwithouthavingtowireseparatelinksforeachrelay.ThissignificantlyreduceswiringcostsbymorefullyutilizingthestationLANbandwidthforthesesignalsandconstructioncostsbyreducingtheneedfortrenching,ducts,conduit,etc.

LowerTransducerCosts

Ratherthanrequiringseparatetransducersforeachdeviceneedingaparticularsignal,asinglemergingunitsupportingSMVcandeliverthesesignalstomanydevicesusingasingletransducerloweringtransducer,wiring,calibration,andmaintenancecosts.

10/12/2014 AdvantagesOfIEC61850|EEP

http://electricalengineeringportal.com/advantagesofiec61850 4/5

LowerCommissioningCosts

ThecosttoconfigureandcommissiondevicesisdrasticallyreducedbecauseIEC61850devicesdontrequireasmuchmanualconfigurationaslegacydevices.ClientapplicationsnolongerneedtomanuallyconfiguredforeachpointtheyneedtoaccessbecausetheycanretrievethepointslistdirectlyfromthedeviceorimportitviaanSCLfile.

Manyapplicationsrequirenothingmorethansettingupanetworkaddressinordertoestablishcommunications.Mostmanualconfigurationiseliminateddrasticallyreducingerrorsandrework.

LowerEquipmentMigrationCosts

BecauseIEC61850definesmoreoftheexternallyvisibleaspectsofthedevicesbesidesjusttheencodingofdataonthewire,thecostforequipmentmigrationsisminimized.Behavioraldifferencesfromonebrandofdevicetoanotherisminimizedand,insomecases,completelyeliminated.

Alldevicessharethesamenamingconventionsminimizingthereconfigurationofclientapplicationswhenthosedevicesarechanged.

LowerExtensionCosts

BecauseIEC61850devicesdonthavetobeconfiguredtoexposedata,newextensionsareeasilyaddedintothesubstationwithouthavingtoreconfiguredevicestoexposedatathatwaspreviouslynotaccessed.AddingdevicesandapplicationsintoanexistingIEC61850systemcanbedonewithonlyaminimalimpact,ifany,onanyoftheexistingequipment.

LowerIntegrationCosts

Byutilizingthesamenetworkingtechnologythatisbeingwidelyusedacrosstheutilityenterprisethecosttointegratesubstationdataintotheenterpriseissubstantiallyreduced.RatherthaninstallingcostlyRTUsthathavetobemanuallyconfiguredandmaintainedforeachpointofdataneededincontrolcenterandengineeringofficeapplication,IEC61850networksarecapableofdeliveringdatawithoutseparatecommunicationsfrontendsorreconfiguringdevices.

ImplementNewCapabilities

TheadvancedservicesanduniquefeaturesofIEC61850enablesnewcapabilitiesthataresimplynotpossiblewithmostlegacyprotocols.Wideareaprotectionschemesthatwouldnormallybecostprohibitivebecomemuchmorefeasible.

BecausedevicesarealreadyconnectedtothesubstationLAN,theincrementalcostforaccessingorsharingmoredevicedatabecomesinsignificantenablingnewandinnovativeapplicationsthatwouldbetoocostlytoproduceotherwise.

Conclusions

IEC61850isnowreleasedtotheindustry.TenpartsofthestandardarenowInternationalStandards(part10isadraftinternationalstandard).Thisstandardaddressesmostoftheissuesthatmigrationtothedigital

10/12/2014 AdvantagesOfIEC61850|EEP

http://electricalengineeringportal.com/advantagesofiec61850 5/5

worldentails,especially,standardizationofdatanames,creationofacomprehensivesetofservices,implementationoverstandardprotocolsandhardware,anddefinitionofaprocessbus.

Multivendorinteroperabilityhasbeendemonstratedandcompliancecertificationprocessesarebeingestablished.DiscussionsareunderwaytoutilizeIEC61850asthesubstationtocontrolcentercommunicationprotocol.IEC61850willbecometheprotocolofchoiceasutilitiesmigratetonetworksolutionsforthesubstationsandbeyond.

SOURCE:RalphMackiewiczSISCO,Inc.SterlingHeights,MIUSA

AboutAuthor//

EdvardCsanyi

EdvardElectricalengineer,programmerandfounderofEEP.HighlyspecializedfordesignofLVhighpowerbusbartrunking(