电气专业变电所设计外文翻译

附录附录A外文资料DesignofMv/LvSubstationTransformerAbstract：Asubstationisapartofanelectricalgeneration,transmission,anddistributionsystem.Substationsgenerallyhaveswitching,protectionandcontrolequipment,andtransformers.ThelowvoltagedistributionnetworksaresuppliedfromMV/LVsubstationtransformerthatrepresentthelaststepofbringingtransformationtothelowvoltageandensuringtheprotectionandmonitoringofthenetwork.TherearethreetypesofMV/LVsubstation:pole-mountedtransformersubstation,thesubstationinanenvelopeandsubstationinmasonry.ThispaperpresentsageneraldescriptionfordifferentMV/LVsubstationandamethodologytodesignthevariouselementsmakingupthepublicdistributionsubstation(choiceoftheemplacement,engineering,powertransformer,choiceofMVcells,circuitbreakers,fuses,disconnectswitch,conductors,...etc).Keywords:SubstationtransformerMVcellsSubstationinmasonryPole-mountedtransformersubstation1.IntroductionAsubstationisapartofanelectricalgeneration,trans-mission,anddistributionsystem.Substationstransformvoltagefromhightolow,orthereverse,orperformanyofseveralotherimportantfunctions.Electricpowermayflowthroughseveralsubstationsbetweengeneratingplantandconsumer,anditsvoltagemaychangeinseveralsteps.Substationsgenerallyhaveswitching,protectionandcontrolequipment,andtransformers.Distributioncircuitsarefedfromatransformerlocatedinanelectricalsubstation,wherethevoltageisreducedfromthehighvaluesusedforpowertransmission.Distributionnetworksaretypicallyoftwotypes,radialorinterconnected.Aradialnetworkleavesthestationandpassesthroughthenetworkareawithnonormalconnectiontoanyothersupply.Thisistypicaloflongrurallineswithisolatedloadareas.Aninterconnectednetworkisgenerallyfoundinmoreurbanareasandwillhavemultipleconnectionstootherpointsofsupply.Thesepointsofconnectionarenormallyopenbutallowvariouscon-figurationsbytheoperatingutilitybyclosingandopeningswitches.Operationoftheseswitchesmaybebyre-motecontrolfromacontrolcenterorbyalineman.Thebenefitoftheinterconnectedmodelisthatintheeventofafaultorrequiredmaintenanceasmallareaofnetworkcanbeisolatedandtheremainderkeptonsupply.TheMV/LVsubstationsareanodeofanetwork,whichincludesasetofequipmentdesignedtoprotectandfacilitatetheoperationoftheelectricalenergy.TheMV/LVsubstationsprovidetheinterfacebetweenthedistributionMVandLV.TheMV/LVadaptstoallmodesofoperationandwhyshouldfulfillthefollowingfunctions:●DistributethepowerandprotecttheLVdepartures;●IsolatetheMV/LVsubstationincaseofdefault;●ManagetheMVnetworkincaseofdefaultandthepositionbyremotecontrol.MV/LVsubstationtransformerhastwopurposes:-Theinterconnectionbetweenthelinesofthesamevoltagelevel,ithelpstodistributethepowerofthedifferentlinesfromsubstations.-Thetransformationofelectricalpower,processorscanswitchbetweenvoltagelevelstoanother.So,wecanclassifytheMV/LVsubstationsoverthenetworksonwhichtheyareusedaswellasthefunctionstheyperform.TherealizationofMV/LVsubstationsneedspriorknowledge:●Standardsofreferenceandstatutoryinstruments(voltage,qualityofsupply,short-circuitpower,...,etc);●Needstobeperforming(powerplantavailability,operation);●Specificneeds-relateduses(voltagevariationstolerated,compensationofreactivepower,immunitytointerferencereceivers,regulationsrelatedtofacilitysecurity);●Constraints,installationandenvironment.ThispaperpresentsthedifferentMV/LVsubstationtransformerandamethodologytodesignthevariouselementsmakingupthepublicdistributionsubstation.2.TheBirthofMV/LVSubstationTransformerThedecisionofaMVorLVsupplywilldependonlocalcircumstancesandconsiderationssuchasthosementionedabove,andwillgenerallybeimposedbytheutilityforthedistrictconcerned.WhenadecisiontosupplypoweratMVhasbeenmade,therearetwowidely-followedmethodsofproceeding:●Thepower-supplierconstructsastandardsubstationclosetotheconsumer’spremises,buttheMV/LVtransformerislocatedintransformerchamberinsidethepremises,closetotheloadcentre.●Theconsumerconstructsandequipshisownsubstationonhisownpremises,towhichthepowersuppliermakestheMVconnection.2.1.ProjectStudiesTheconsumermustprovidecertaindatatotheutilityattheearlieststageoftheproject.thepower-suppliermustindicate:●Thetypeofpowersupplyproposed,anddefinethekindofpower-supplysystem:overheadlineorunder-ground-cablenetwork,theserviceconnectiondetails:single-lineservice,ring-maininstallation,orparallelfeeders,andthepower(kVA)limitandfaultcurrent.●Thenominalvoltageandratedvoltage(Highestvolt-ageforequipment)●Meteringdetailswhichdefine:Thecostofconnectiontothepowernetworkandtariffdetails(consumptionandstandingcharges).2.2.ImplementationBeforeanyinstallationworkisstarted,theofficialagreementofthepower-suppliermustbeobtained.Therequestforapprovalmustincludethefollowinginformation,largelybasedonthepreliminaryexchangesnotedabove:●Locationoftheproposedsubstation;●Single-linediagramofpowercircuitsandconnections,togetherwithearthing-circuitproposals;●Fulldetailsofelectricalequipmenttobeinstalled,includingperformancecharacteristics;●Layoutofequipmentandprovisionformeteringcomponents;●Arrangementsforpower-factorimprovementifrequired;●Arrangementsprovidedforemergencystan