110kv变电站一次系统设计

****大学毕业设计（论文）说明书-1-摘要变电站作为电力系统中的重要组成部分，直接影响整个电力系统的安全与经济运行。根据任务书的要求，本次设计为110kV降压变电站一次系统设计。拟建的变电站在整个电力系统中起着汇聚和分配电能的作用。担负着向该地区工厂和农村供电的重要任务。本说明书主要阐述了110kV**变电所各设计阶段的设计依据、原则和方法，各方案的拟订、比较以及设计选择的结论。先对变电站的原始资料进行分析，根据原始资料上所给系统与线路及所有出线处负荷的参数，计算出35kV和10kV两个电压等级处的总负荷。然后通过计算得到110kV侧的总负荷。因为还要考虑到远期发展，所以通过一个负荷增长率来得到各电压等级侧的远期负荷。接着通过对拟建变电站的概括以及各电压等级出线方向的考虑，先分别为三个电压等级确定几个可选择的电气主接线方案，通过对各种方案的可靠性、灵活性分析和经济性比较，最终确定了所设计变电站的电气主接线方案。然后，根据负荷情况和变电站所在地区的地理情况选择了主变压器的型号。接下来选取基准值，计算出主变压器各绕组的电抗的标幺值，画出等值电抗图，并对各电压侧的三相短路进行短路电流分析计算。根据短路电流计算结果对变电所的各电压等级侧的断路器、隔离开关、电流互感器、电压互感器、开关柜、母线，避雷器等进行了选择和校验。最后进行了110kV变电站防雷保护和接地的简要说明。本设计中，结合了相关的设计手册，辅助资料和国家有关规程，翻阅并参考了有关国内外最常用的设计方法、研究成果和大量的电气设备，并从中选择最适合本次设计使用的设计方法和电器设备。由于条件的限制，和本人知识和经验的欠缺，本次毕业设计只是对110kV变电站电气一次部分作了较简单的设计，而对于变电站的继电保护，无功补偿和总平面布置方面做忽略处理。希望在以后的学习和工作中可以进行更深入的学习和研究。关键字：电气主接线；主变压器选择；短路电流计算；设备选择；稳定校验****大学毕业设计（论文）说明书-2-AbstractPowersystemsubstationasanimportantpartofadirectimpactontheentirepowersystemsecurityandeconomicoperation.Accordingtotherequirementsofthetaskbook,thisonedesignedto110kVstep-downsubstationsystem.Theproposedsubstationinthepowersystemplaystheroleofaggregationanddistributionofelectricenergy.Factoriesintheregionandbearstheimportanttaskofruralelectrification.Thismanualexpoundsthe110kVsubstation**designbasisforthedesignphase,principlesandmethods,theprogramdevelopment,comparisonandconclusionofdesignoptions.Firstsubstationoftheoriginaldata,accordingtotheoriginaldataonthesystemloadline,andalltheparametersofoutletDepartmentcalculatedtwovoltage10kV35kV,andthetotalloadofoffice.Thencalculatedthetotalloadof110kVside.Alsoinconsiderationoflong-termdevelopment,sotogetthroughaloadgrowthrateoftheforwardsideoftheloadvoltage.Thensummarizedbytheproposedsubstationandthedirectionoftheoutletvoltageconsiderations,thefirstthreevoltagelevelsrespectivelytodeterminethemainelectricalconnectionofseveralalternativeprograms,throughvariousprogramsofthereliability,flexibilityanalysisandeconomicnaturecomparison,finalizedthedesignofsubstationmainelectricalconnectionplan.Then,accordingtoloadconditionsandthegeographicareasubstationstochoosethemodelofthemaintransformer.Next,selectthereferencevalue,calculatethemaintransformerwindingreactanceperunitvalue,theequivalentreactancegraphdrawing,andthevoltagesideofthethree-phaseshort-circuittoshortcircuitcurrentcalculation.Accordingtoshort-circuitcurrentcalculationofthevoltagelevelsonthesubstationsideofthecircuitbreaker,disconnectingswitches,currenttransformers,voltagetransformers,switchgear,busbar,lightningarrester,etc.,wereselectedandverified.Finally,110kVsubstationlightningprotectionandearthingofthedesignbrief.Thisdesign,combinedwithrelevantdesignmanual,supportinginformationand****大学毕业设计（论文）说明书-3-relevantnationalregulations,readandrefertothemostcommonlyusedondomesticandforeigndesign,researchandalotofelectricalequipment,andchoosethemostsuitabledesignforuseofthisdesignmethodsandelectricalequipment.Duetoconstraints,andmylackofknowledgeandexperience,thisgraduationdesignisonlyonepartoftheelectricalsubstationonthe110kVmadeamoresimpledesign,andforsubstationrelayprotection,reactivepowercompensationandgenerallayoutdonedealignored.Hopeinafuturestudyandworkcanbemorein-depthstudyandresearch.Keyword:Mainelectricalconnection；Choiceofmaintransformer；Short-circuitcurrentcalculation；Equipmentselection；Stabilitytest****大学毕业设计（论文）说明书-4-目录1绪论····························································································12设计要求及负荷计算·······································································32.1设计要求··············································································32.2负荷计算··············································································32.2.1原始资料····································································32.2.2计算过程····································································43电气主接线的设计··········································································63.1电气主接线概述·····································································63.2电气主接线的基本要求···························································63.3电气主接线的设计原则···························································73.4主接线的基本形式和特点························································73.5主接线的选择······································································103.5.1110kV侧主接线选择····················································103.5.235kV侧主接线选择·····················································113.5.310kV侧主接线选择·····················································123.5.4变电站的主接线·························································124主变压器的选择···········································································134.1主变选择原则······································································134.2主变容量和台数的选择·························································134.3主变型式的选择···································································144.3.1相数的选择·······························································144.3.2绕组数量和连接组别的选择································