SubstationDesignPowersystemisthesystemofproductionandconsumptionofelectricitygeneration,transmission,transformation,distributionandelectricityandotheraspectsofthecomposition.Itsprimaryfunctionistheenergyconversionmeansthroughnaturalgenerationpowerintoelectricalenergy,andthenbytransmissionanddistributionsubstationandsuppliespowertoeachuser.Themainstructureofthepowersystemhaspower(hydropower,thermalpowerplants,nuclearpowerplants,etc.),substations(boostsubstation,loadcentersubstation,etc.),transmissionanddistributionlinesandloadcenters.Eachpowerpointisalsointerconnectedtoachieveenergyexchangebetweendifferentregionsandregulationtoimprovesecurityofsupplyandeconomy.Substationtransmissionlinenetworkconsistingoftheelectricitynetworkandisusuallycalled.Substationisfromthemainterminal,themaintransformers,highandlowvoltagepowerdistributionequipment,relayprotectionandcontrolsystems,thepowerandDCsystems,remoteandcommunicationsystems,thenecessaryreactivepowercompensationdeviceandthemaincontrolroomandothercomponents.Amongthem,themainterminal,themaintransformers,highandlowvoltagepowerdistributionequipment,suchasbelongingtoasystem;protectionandcontrolsystems,theDCsystem,remoteandcommunicationsystemsaresecondarysystem.Mainconnectionisthemostimportantpartofthesubstation.Itdeterminesthefunctionofthesubstation,construction,investment,operationquality,maintenanceconditionsandsupplyreliability.Generallydividedintoseveralbasicformssinglebusbar,doublebusbar,ahalfbreakerandringwiringandsoon.Substationmaintransformeristhemostimportantequipment,whichdirectlyaffectstheperformanceandconfigurationoftheadvancednatureofthesubstation,economyandreliability.Generalneedtoinstallsubstationmaintransformer2to3sets;330kVandbelow,themaintransformerisusuallyathree-phasetransformer,itscapacityby5to10yearsintotheexpectedloadselection.Inaddition,substationsandotherequipmentselectionandtheoveralllayoutofthesiteselectionalsohavespecificrequirements.Substationrelayprotectionsubsystem(includingtransmissionlinesandbusprotection)andcomponentprotection(includingtransformers,reactorsandreactivepowercompensationdeviceprotection)categories.Substationcontrolmodeisgenerallydividedintothedirectcontrolandoptionalcontroltwocategories.Transformersubstationisthemainequipmentisdividedintotwo-windingtransformer,three-windingtransformersandautotransformersthathighandlowvoltagewindingsforeachphaseofashared,takingaheaderfromthemiddleofthehighvoltagewindingqualifyasalow-voltagewindingofthetransformer.Voltageisproportionaltothelevelofthewindingturns,thecurrentisinverselyproportionaltothenumberofturns.Transformerscanbeclassifiedaccordingtotheirroleandstep-downtransformerstep-uptransformer.Theformerisusedtosendendsubstationpowersystem,whichisusedbytheendofthesubstation.Voltagetransformerandvoltageofthepowersystemneedstoadapt.Inordertomaintainacceptablevoltageunderdifferentloadconditionsmayneedtoswitchthetransformertap.Bywayoftransformertapswitchwithload-loadandno-loadregulatingtransformerno-loadtapchanger.OLTCismainlyusedbytheendofthesubstation.Voltageandcurrenttransformers.Theiroperatingprincipleissimilartothetransformer,whichtheoperatingvoltageofhighvoltageequipmentandbusbar,highcurrentthatthedeviceandthebusloadorshort-circuitcurrentmeasurementinstrumentsaccordingtoapredeterminedratiobecomeslowvoltagerelayprotectionandcontrolequipmentandasmallcurrent.Operationatratedvoltagetransformersecondaryvoltagel00V,currenttransformersecondarycurrentis5Aor1A.Currenttransformersecondarywindingisoftenconnectedwiththeloadclosetoashortcircuit,pleasenote:neverletitopen,otherwiseitwillendangerduetohighvoltageequipmentandpersonalsafetyortothecurrenttransformerburned.Switchgearincludescircuitbreakers,isolatingswitches,loadswitches,highvoltagefusesaredisconnectedandclosethecircuitdevices.Breakersaregenerallycomposedofacontactsystem,arcsystem,operationmechanism,release,housingandsoon.Theroleofthecircuitbreakeristurnedoffandtheloadcircuit,andcutoffthefaultcircuittopreventtheaccidentandensuresafeoperation.Thehigh-voltagecircuitbreakerstobreaking1500V,current1500-2000Aarc,whichcanbestretchedto2marccontinuestoburnisnotextinguished.Itisahighvoltagecircuitbreakerinterruptermustbeaddressed.Blowingarcextinctionofthearcprincipleisdiminishedheatfreecooling,ontheotherhandbyblowingarcelongatedarcreinforcedcompositeanddiffusionofchargedparticles,whilethearcgapofchargedparticlesdispersequicklyrestorethedielectricstrengthofthemedium.Isolationswitch(knife)primaryroleistoisolatethevoltageatthedeviceorlinemaintenance,toensuresafety.Itdoesnotdisconnecttheloadcurrentandshort-circuitcurrent,shouldbeusedinconjunctionwiththecircuitbreaker.Afterapoweroutageshouldpullisolationswitchbeforepullingcircuitbreakers,powertransmissionshouldbefitafterisolationswitchisclosedcircuitbreaker.Ifmisusewillcauseequipmentdamageandpersonalinjury.Theabilitytobeabletodisconnecttheloadswitchwithoutdisconnectingtheloadcurrentfaultcurrentinnormaloperation,generallyusedforhigh-voltagetransformerfusewithorwithoutoutletvoltage10kVandaboveregularoperations.Inordertoreducetheareasubstationpositivedevelopmentinrecentyears,sulfurhexafluorideenclosedSwitchgear(GIS).Itisthecircuitbreakers,disconnectors,busbar,groundingswitches,transformers,bushingorcableterminalswereinstalledintheirprimeinconcentratedformasealbetweentheoverallenclosurefilledwithsulfurhexafluoridegasasinsulatingmedium.Thiscombinationhasacompactstructure,smallappliancesandlightweightwithoutaffectingatmosphericconditions,longmaintenanceintervals,noelectricshockandelectricalnoise,etc.,havebeenputintooperationbeforethedevelopmentof765kVsubstation.Currently,itsdisadvantageisexpensive,requirehighmanufacturingandmaintenanceprocesses.Readyforoperationmanagementofsubstationistoachievesafe,reliable,reasonableandanimportantguaranteeofeconomicpower.Sosubstationdesignmustmeettherequirements,sobasedonevidence.變電站設(shè)計(jì)電力系統(tǒng)是由發(fā)電、輸電、變電、配電和用電等環(huán)節(jié)組成的電能生產(chǎn)與消費(fèi)系統(tǒng)。它的功能是將自然界的一次能源通過(guò)發(fā)電動(dòng)力裝置轉(zhuǎn)化成電能，再經(jīng)輸電、變電和配電將電能供應(yīng)到各用戶。電力系統(tǒng)的主體結(jié)構(gòu)有電源（水電站、火電廠、核電站等發(fā)電廠），變電所（升壓變電所、負(fù)荷中心變電所等），輸電、配電線路和負(fù)荷中心。各電源點(diǎn)還互相聯(lián)接以實(shí)現(xiàn)不同地區(qū)之間的電能交換和調(diào)節(jié)，從而提高供電的安全性和經(jīng)濟(jì)性。輸電線路與變電所構(gòu)成的網(wǎng)絡(luò)通常稱電力網(wǎng)絡(luò)。變電所由主接線，主變壓器，高、低壓配電裝置，繼電保護(hù)和控制系統(tǒng)，所用電和直流系統(tǒng)，遠(yuǎn)動(dòng)和通信系統(tǒng)，必要的無(wú)功功率補(bǔ)償裝置和主控制室等組成。其中，主接線、主變壓器、高低壓配電裝置等屬于一次系統(tǒng)；繼電保護(hù)和控制系統(tǒng)、直流系統(tǒng)、遠(yuǎn)動(dòng)和通信系統(tǒng)等屬二次系統(tǒng)。主接線是變電所的最重要組成部分。它決定著變電所的功能、建設(shè)投資、運(yùn)行質(zhì)量、維護(hù)條件和供電可靠性。一般分為單母線、雙母線、一個(gè)半斷路器接線和環(huán)形接線等幾種基本形式。主變壓器是變電所最重要的設(shè)備，它的性能與配置直接影響到變電所的先進(jìn)性、經(jīng)濟(jì)性和可靠性。一般變電所需裝2～3臺(tái)主變壓器；330千伏及以下時(shí)，主變壓器通常采用三相變壓器，其容量按投入5～10年的預(yù)期負(fù)荷選擇。此外，對(duì)變電所其他設(shè)備選擇和所址選擇以及總體布置也都有具體要求。變電所繼電保護(hù)分系統(tǒng)保護(hù)（包括輸電線路和母線保護(hù)）和元件保護(hù)（包括變壓器、電抗器及無(wú)功補(bǔ)償裝置保護(hù)）兩類。變壓器是變電站的主要設(shè)備，分為雙繞組變壓器、三繞組變壓器和自耦變壓器即高、低壓每相共用一個(gè)繞組，從高壓繞組中間抽出一個(gè)頭作為低壓繞組的出線的變壓器。電壓高低與繞組匝數(shù)成正比，電流則與繞組匝數(shù)成反比。變壓器按其作用可分為升壓變壓器和降壓變壓器。前者用于電力系統(tǒng)送端變電站，后者用于受端變電站。變壓器的電壓需與電力系統(tǒng)的電壓相適應(yīng)。為了在不同負(fù)荷情況下保持合格的電壓有時(shí)需要切換變壓器的分接頭。按分接頭切換方式變壓器有帶負(fù)荷有載調(diào)壓變壓器和無(wú)負(fù)荷無(wú)載調(diào)壓變壓器。有載調(diào)壓變壓器主要用于受端變電站。電壓互感器和電流互感器。它們的工作原理和變壓器相似，它們把高電壓設(shè)備和母線的運(yùn)行電壓、大電流即設(shè)備和母線的負(fù)荷或短路電流按規(guī)定比例變成測(cè)量?jī)x表、繼電保護(hù)及控制設(shè)備的低電壓和小電流。在額定運(yùn)行情況下電壓互感器二次電壓為l00V，電流互感器二次電流為5A或1A。電流互感器的二次繞組經(jīng)常與負(fù)荷相連近于短路，請(qǐng)注意：絕不能讓其開路，否則將因高電壓而危