FunctionandnumberedprincipleofsecondaryelectricpowerequipmentCONTENTSPAGEFamiliarwiththeroleofsecondaryelectricpowerequipment0102Familiarwiththecompositionand

functionoftheSecondarycircuitofpowerequipment03Befamiliarwiththeclassificationofthesecondarycircuitdrawings04Familiarwiththegraphicsymbols,textsymbolsandnumberingprinciplesofthesecondaryequipmentBefamiliarwiththeclassificationofthesecondarycircuitdrawingsFamiliarwiththeroleofsecondaryelectricpowerequipment01FamiliarwiththeroleofsecondaryelectricpowerequipmentInpowersystems,itisusuallydividedintoprimaryandsecondaryequipmentaccordingtothefunctionoftheelectricalequipment.Primaryequipmentreferstotheelectricalequipmentdirectlyusedfortheproduction,transmissionanddistributionofelectricity,includingthegenerator,powertransformer,circuitbreaker,isolationswitch,busline,powercableandtransmissionlines,etc.,whichisthemainbodyofthepowersystem.secondaryelectricpowerequipmentSecondaryequipmentisalow-voltageelectricalequipmentusedformonitoring,measuring,controlling,protectingandregulatingtherunningconditionsoftheprimaryequipmentinthepowersystem,includingarelayprotectiondevice,measurementandcontroldevice,automaticdevice,operationmonitoringsignal,automaticmonitoringsystem,communicationequipment,etc.Italsousuallyincludessecondarywindingleads

wireofthe

voltagetransformerandcurrenttransformer,andDCpowersupplyforthestation.CompositionandfunctionofSecondarycircuitofpowerequipment02CompositionandfunctionofsecondarycircuitofpowerequipmentAcircuitconnectingthesecondaryequipmenttogetheraccordingtocertainrequirementsiscalledsecondarywiringorsecondarycircuit.Drawingsdescribingthesecondarywiringarecalledasecondarywiringdiagramorasecondarycircuitdiagram.Secondarycircuitisanimportantpartofthepowerplantandsubstation,andanimportantguaranteeforthesafe,economicandstableoperationofthepowersystem.(I)ControlsystemThefunctionofthecontrolsystemistotripandclosetheswitchgearofthesubstationinplace

orinthedistance,

tomeettherequirementsofchangingtheoperationmodeofthemainsystemanddealingpowersystem

faults.Thecontrolsystemconsistsofacontroldevice,acontrolobject,andacontrolnetwork.Inthecomprehensiveautomaticsubstation,thecontrolsystemcontrolmodehastwokinds:remotecontrolandlocalcontrol.Amongthem,theremotecontrolhasthesubstationterminalcontrolandscheduling(orcentralizedcontrolcenter)terminalcontrolmode;thelocalcontrolhasoperating

mechanismandprotection(ormonitoring)screencontrolmode.Thesecondarycircuithasvariousfunctions,mainlyincludingthefollowingcontents:CompositionandfunctionofsecondarycircuitofpowerequipmentThesecondarycircuithasvariousfunctions,mainlyincludingthefollowingcontents:(2)SignalsystemThefunctionofthesignalsystemistodisplaytheoperationstateofthecorrespondingprimaryequipmentaccuratelyandtimely,andtoprovideareliablebasisfortheoperation,adjustmentandfaulttreatmentfortheoperators.Thesignalsystemiscomposedofasignaltransmissionmechanism,asignalreceivinganddisplayelement(device)anditsnetwork.Accordingtothenatureofsignal,itcanbedividedintopositionsignal,abnormalsignalandaccidentsignal.Commonpositionsignalsincludecircuitbreakerpositionsignal,variousswitchpositionsignals,transformergearsignal,etc.;commonabnormalsignalandaccidentsignalshaveprotectiveactionsignal,devicefaultsignalandvariousabnormalsignalsmonitoredbycircuitbreaker.CompositionandfunctionofsecondarycircuitofpowerequipmentThesecondarycircuithasvariousfunctions,mainlyincludingthefollowingcontents:(3)MeasurementandtestingsystemThefunctionofthemeasurementandmonitoringsystemistoindicateorrecordtheoperationparametersoftheelectricalequipmentandthetransmissionlines,asthebasisfortheoperatorstomastertheoperationsituationofthemainsystem,faulthandlingandeconomicaccounting.Themeasurementandmonitoringsystemconsistsofvariouselectricalmeasuringinstruments,monitoringdevices,switchingswitchesandtheirnetworks.Substationiscommonwithcurrent,voltage,frequency,power,electricityandothermeasurement,AC,DCinsulationmonitoringsystem.(4)AdjustmentsystemThefunctionoftheadjustmentsystemistoadjusttheoperatingparametersofsomemainequipmenttoensurethesafety,economicandstableoperationofthemainequipmentandpowersystem.Theadjustmentsystemiscomposedofmeasuringmechanism,transmissionequipment,automaticcontroldevice,actuatorelementsanditsnetwork.Commonusedadjustmentsaremanual,automaticandsemi-automatic.CompositionandfunctionofsecondarycircuitofpowerequipmentThesecondarycircuithasvariousfunctions,mainlyincludingthefollowingcontents:(5)RelayprotectionandautomaticdevicesystemThefunction

ofrelayprotectionandautomaticdeviceisthatwhenthepowersystemfails,automatically,quicklyandselectivelyremovethefault,reducethedamageoftheequipment,ensurethestabilityofthepowersystem,increasethereliabilityofpowersupply;timelyreflecttheabnormalworkingstateofthemainequipment,prompttheoperatorstopayattentiontoandprocessing,ensuretheintegrityofthemainequipmentandthesafetyofthesystem.Relayprotectionandautomaticdevicesystemconsistsofsecondarywindingofvoltageandcurrenttransformer,relayprotectiondevice,automaticdevice,circuitbreakerandanditsnetwork.CompositionandfunctionofsecondarycircuitofpowerequipmentThesecondarycircuithasvariousfunctions,mainlyincludingthefollowingcontents:(6)OperatingthepowersupplysystemTheoperatingpowersupplysystemistheworkingpowersupplyfortheabovesecondarysystems,tripping,switching

powersupplyandaccidentpowersupplyofthecircuitbreaker.Undernormalandfaultconditions,itisusuallycomposedofDCpowersupplyequipment(includingbatteryandcharger),monitoringequipmentandpowersupplynetwork.CompositionandfunctionofsecondarycircuitofpowerequipmentClassificationofthesecondarycircuitdrawings03ClassificationofthesecondarycircuitdrawingsAccordingtothefunctionofthedrawings,thedrawingsofthesecondarycircuitcanbedividedintoschematicdrawingsandinstallationdrawings.Theschematicdiagramisthedrawingreflectingtheworkingprincipleofthesecondarycircuit,whichcanbedividedintocentralized

schematicdiagramandexpansionschematicdiagramaccordingtotheformofitsperformance.Theinstallationdiagramisdividedintolayoutdrawing

andinstallationwiringdiagramaccordingtoitsfunction.Classificationofthesecondarycircuitdrawings（1）

centralizedschematicdiagramThecentralizedschematicdiagramexpressestheworkingprincipleinthedrawing,suchastheinterconnectedcurrentcircuit,voltagecircuitandDCcircuit,etc.Therefore,thiswiringdiagramischaracterizedbyenablingthegraphreadertohaveaclearoverallconceptofthecompositionofthewholesecondaryloopandtheactionprocess.Thedisadvantageisthatthedetailsofthesecondarycircuitarenotenough,cannotindicatetheactualpositionofthewiringbetweentheelements,doesnotreflecttheinternalwiring,terminallabel,circuitlabelofeachelement,whichisnotconvenientforthemaintenanceanddebuggingonsite,andisdifficultforthecomplexsecondarycircuitreading.Therefore,inpracticaluse,theexpansionschematicdiagramiswidelyused.AsshowninFigure1isthecentralizedschematicdiagramofovercurrentprotection.Figure1centralizedschematicdiagram

ofovercurrentprotectionClassificationofthesecondarycircuitdrawings(2)

expansionschematicdiagramTheexpansionschematicisdividedbyeachindependentpowersupplyofthesecondarycircuit.SuchasACcurrentcircuit,ACvoltagecircuit,DCcontrolcircuit,relayprotectioncircuitandsignalcircuit,etc.Accordingtothisprinciple,thecurrentcoil,voltagecoilandcontactsbelongingtothesameelementmustbedrawnindifferentcircuitsrespectively.Inordertoavoidconfusion,thecoil,contactsbelongingtothesameelementarerepresentedbythesametextsymbol.Figure2SchematicdiagramofovercurrentprotectionexpansionThewiringoftheexpansionschematicisclearandeasytoread,whichiseasytomastertheoperationprocessandworkingprincipleofthewholerelayprotectionandthesecondarycircuit.Especiallyinthesecondarycircuitofthecomplexrelayprotectiondevice,theexpansionschematicshowsitsmoreprominentadvantages.AsshowninFigure2,theovercurrentprotectionexpansionschematic.Classificationofthesecondarycircuitdrawings(3)LayoutdrawingoftheprotectivecabinetThelayoutdrawingoftheprotectivecabinetisthebasisforprocessing,manufacturingandinstallingtheequipmentonthecabinet.Thearrangementofeachelementonthecabinetshallbedeterminedaccordingtotherationalityofoperationandconsideringtheconvenienceofmaintenance,operationandconstruction,whichshallbedrawnaccordingtoacertainproportionandmarked.ClassificationofthesecondarycircuitdrawingsThecabinetlayoutdrawingisin

frontviewtounderstandandbefamiliarwiththeconfigurationandarrangementorderoftheequipment(elements)onthecabinetfromthe

frontofthecabinet.Equipment(components)onthecabinetarenumberedaccordingtocertainrulesandtextsymbols.Textsymbolsareconsistentanduniquewiththesymbolsontheexpansionschematictofacilitatemutualaccessandcontrol.Thearrangementoftheequipment(components)onthecabinetarebasedontherationalityoftheoperationandtheconvenienceofmaintenance,operationandconstruction.Inthecabinetequipmenttablelistednexttothecabinetdiagram,thesequencenumber,symbol,name,model,technicalparameters,quantityandquantityofeachequipment(element)shallbeindicated.Ifadevice(element)isinstalledintherearof

thecabinet,itshouldbeindicatedintheremarkscolumnoftheequipmenttable.Classificationofthesecondarycircuitdrawings(4)WiringdiagramonthebackofthecabinetThewiringdiagramonthebackofthecabinet

isbasedonthecabinet

layoutandtheprincipleexpansiondiagram.Itisthebackviewusedbythestaffwhenworkingbehindthecabinet.Therefore,thearrangementoftheequipmentcorrespondstothecabinet

layout,andtheleftandrightdirectionisjustoppositetothecabinetlayout

drawing.Fortheconvenienceofwiring,eachelementandtheterminalrowarenumberedbyrelativenumberingintheinstallationwiringdiagramtoillustratethemutualconnectionbetweentheseelements.ClassificationofthesecondarycircuitdrawingsThewiringdiagramonthebackofthecabinetcanbedividedintotheequipmentwiringdiagramandtheterminalrowinstallationwiringdiagram.Themainfunctionistoshowtheconnectionbetweentheequipment(elements)inthecabinetandthebackoftheequipment(elements)andtheterminalrow;thelatterisspeciallyusedtoindicatetheconnectionbetweentheequipmentinthecabinetandtheoff-cabinet

equipment.

Cablesbetweentheterminalblockanddevicesonthecabinet

aremarkedontheinsideoftheterminalblock.Cableconnectionsbetweentheterminalblockanddevicesoutsidethecabinet

aremarkedoutsidetheterminalblock.Theconnectionoftheequipment

outsidethecabinetismainlycable.Clearlythenumber,destination,cablenumber,corenumberandsectionofeachcableshouldbemarked,andeachcircuitshallbemarkedaccordingtotheprincipleofequalpotential.ClassificationofthesecondarycircuitdrawingsGraphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment04Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipmentInordertofacilitatethedesign,manufacture,installation,commissioningandoperationandmaintenance,thegraphicsymbolsandtextsymbolsofthecomponentsareusuallyusedonthedrawingstoconnectaccordingtocertainrulestodescribethesecondarycircuit.Thiskindofdrawingswecallthesecondarycircuitwiringdiagram.Theequipment,elementsorfunctionalunitsorotheritemsinthesecondarycircuitwiringdiagrammustbeillustratedwithgraphicsymbols,textsymbolsandcircuiticonnumbers.Graphicsymbolsandtextsymbolsareusedtorepresentanddistinguisheachelectricalequipmentinthesecondarycircuit,andthecircuiticonnumberisusedtodistinguishthevariouscircuitsconnectedbetweentheelectricalequipment.Thegraphicalsymbols,textsymbolsandcircuiticonnumbersinthesecondarywiringdiagramallhavenationalandinternationalstandards.(1)DrawingsymbolGraphicalsymbolsareusedtovisuallyrepresentanydevice,element,functionalunit,andotheritemsinthesecondaryloopdiagram.Atpresent,GraphicSymbolsforElectricalMap,Part7:Switch,ControlandProtectionDevices(GB/T4728.7-2008/IEC60617database),GraphicSymbolsforElectricalMap,Part8:MeasurementMeters,LightsandSignalDevices(GB/T4728.8-2008/IEC60617database),etc.,theform,contentandquantityofsymbolsareexactlythesameasthecurrentlyusedinternationalIEC60617standards.Butforavarietyofreasons,somedepartmentspainted,usedbythegraphicsymbolsorearlierstandards.Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipmentComponents,devicesandequipmentarerepresentedbygraphicalsymbolsinstandardelectricaldiagramsandaredrawnintheir"normalstate".The

"normalstate"meansthattheelements,devicesandequipmentinthecircuithasnovoltagepresenceornoexternalforce,suchastherelayandcontactorcoilarenotcharged(orthepassingvoltagedoesnotreachtheactionvalue);theisolationswitchandcircuitbreakerinthedisconnectedposition,buttons,travelswitchintheshelvedposition,etc.AsshowninFigures1,2,and3.Figure1.RelayFigure2On(normallyopen)/off(normallyclosed)contactoftherelayFigure3CircuitBreaker/isolationswitchGraphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment(2)TextsymbolsTextsymbolsareusedincombinationwithgeneralgraphicsymbolsasqualifyingsymbols,whichcandistinguishdifferentequipment(components)anditemssuchasequipment(components)orfunctionalunitswithdifferentfunctionsinthesameequipment(components)inmoredetail.Thegeneralruleforcompilingthecodesofcommonlyusedelectricalequipment(components)isthatthetextsymbolsshouldbeabbreviatedaccordingtotheEnglishtermsspecifiedintherelevantnationalstandardsorprofessionalstandardsforelectricalterminology,andthefirstletterofthewordisusedtoformthetextsymbols,generallynot.morethanthreeletters.Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment1.MathematicsserialnumberItrepresentstheserialnumberofsimilarequipmenttodistinguishthesequencenumberofsimilarequipmentorelementsinthesameelectricaldrawingunit.Forexample,1TV,TVisavoltagetransformertextsymbol,and1representstheserialnumberofthesamedevice.Whenthesameelectricalunitcontainstwoormoredevicesorelementsofthesameset,addnumericnumbersinfrontofthebasictextsymbol.Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment2.basictext

symbolBasictextsymbolsareanecessaryiteminthecompositionoftextsymbolsusedtorepresentthetypeofdeviceorelement.Thebasictextsymbolsaredividedintosingle-lettersymbolsandtwo-lettersymbols.Thesingle-lettersymbolusestheLatinalphabettodividevariouselectricalequipmentandcomponentsinto23categories,andeachclassisrepresentedbyadedicatedlettersymbol,Two-lettersymbolsareusedonlywhensingle-lettersymbolscannotmeettherequirementsandrequirefurtherdivisionofthelargeclasses.Thecombinedformoftwo-lettersymbolsisasingle-lettersymbolintheanteriorandanotherletterislistedintheposteriororder.Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment3.auxiliarylettersymbolAuxiliarytextsymbolsareusedtorepresentthefunctions,states,andmainfeaturesofelectricalequipment,devices,andcomponents,andlines,usuallyconsistingofthefirstoneortwolettersofanEnglishword.Auxiliarytextsymbolsaregenerallyplacedatthebackofthebasictextsymbolstoformthecombinedtextsymbols.Auxiliarytextsymbolscannotbeusedalone,butmustbecombinedwiththebasictextsymbolstoformacompletetextsymbol.Forexample,VandAinTVandTAareallauxiliarytextsymbols,indicatingthevoltageandcurrent,respectively.Graphicsymbol,textsymbol,numberingprincipleofthesecondaryequipment1.EquipmentstandardnumberInthepast,RomannumeralsandArabicnumberswerecommonlyusedforinstallationdrawingswithalargenumberofequipmentinthescreen(box).Atpresent,thecomputerprotectioncabinetusuallyuses1n,2ntoindicatethedevicenumberof2n.(3)PrinciplesofnumberingGraphicsymbol,textsymbol,numberingprincipleofthesecondaryequipmentKnowledge

preparationPrincipleofdevicemarkingintheprotectioncabinetIntheStandardizationDesignCodeofQ/GDW1161-2014LineProtectionandAuxiliaryEquipment,Q/GDW1175-2013Transformer、HighVoltageShuntReactorandBusProtectionandAuxiliaryEquipment,thestandardprincipleofprotectivecabinetdevicesandtheirterminalrowsisstandardized.DetailsaregiveninTable1andTable2.BasicknowledgeofsubstationsecondarycircuitordernumberDevicetypeUnitstandardnumberCabinetterminalblocklabelllineprotection1n1D2Lineindependentbackupprotection(optional)2n2D3Circuitbreakerprotection(withreccoincidence)3n3D4Operationbox,circuitbreakerintelligentterminal4n4D5TheACvoltageswitchingbox7n7D6Overvoltageandremotetripprotection9n9D7Shortleadprotection10n10D8Distantsignaltransmissiondevice,transceivermachine11n11D9Relayprotectioncommunicationinterfacedevice24n24D10mergecells13n13DordernumberDevicetypeUnitstandardnumberCabinetterminalblocklabellTransformerprotection,highresistanceprotectionandbusprotection1n1D2Operationbox,circuitbreakerintelligentterminal,busintelligentterminal4n4D3Transformernon-powerprotection,highanti-non-powerprotection,bodyintelligentterminal5n5D4TheACvoltageswitchingbox7n7D5BusCoupling(Section)Protection8n8D6mergecells13n13DTable1LineprotectionandauxiliaryequipmentlabelingprincipleTable2Componentprotectionandauxiliarydevicelabelingprinciples2.EquipmentterminaldesignationEachdevicehasclearlabelsonitsterminalswhenitleavesthe