220kV降压变电站电气部分设计摘要变电站是电力系统的一个重要的组成部分，它直接影响着整个电力系统的安全与经济运行，是联系发电厂与用户的中间环节，起着变换和分配电能的作用。本文主要针对220kV一次降压变电站电气部分进行设计。根据任务书，设计的主要内容包括主变的选择、电气主接线方案的比较与确定、短路计算、电气设备选型、系统暂态稳定分析、继电保护配置等。本文对主变的选择、电气主接线的选择、配电装置的规划、继电保护的配置进行了详细的说明。本文的重点计算包括设备的选择校验计算、继电保护计算。本次设计既满足了电力系统安全、经济、可靠的基本要求，又重视了电力系统长期规划和长远的发展。对变电站的设计，是一次较为综合性的实践过程，是对以往所学专业知识的系统的总结和提高。本设计属于变电所电气部分的初步设计，基本能满足任务书的要求。关键词：变电站设计，电气设备选型，暂态稳定，继电保护-1-AbstractSubstationisanimportantpartofpowersystem,whichdirectlyinfluencesthewholepowersystemsafetyandeconomicaloperation,islinkedtopowerplantsandusersoftheintermediatelinks,playsaroleintransfermationanddistributionofelectricenergy.Thispapermainlyisaimedattheelectricalpartdesignofa220kvstep-downtransformersubstation.Accordingtothespecification,themaincontentsofthedesignincludetheselectionofmaintransformer,themainelectricalwiringschemecomparisonanddetermination,shortcircuitcalculation,electricequipmenttypeselection,systemtransientstabilityanalysisandrelayprotectionconfiguration,etc.Inthispaper,theselectionofmaintransformerandmainelectricalwiring,powerdistributionequipmentplanningandtheconfigurationofrelayprotectionwillbeinthedetail.Thefocusofthispaperincludsthevalidationcalculationofselectedequipmentandrelayprotectioncalculation.Thisdesignwillnotonlymeetthebasicrequirementsofpowersystemsecurity,economic,reliable,butalsotothelong-termplanningandlongtermpowersystemdevelopment.Thedesignofsubstation,isamorecomprehensivepracticeprocessandasummaryandimprovementofpreviouslyprofessionalknowledge.Thisdesignispartofthepreliminarydesignoftheelectricalsubstation,basiclycanmeetthespecificationrequirements.Keywords：Substationdesign,electricalequipmentselection,transientstability,Relayprotection-2-目录摘要........................................................................................................................................-1-Abstract................................................................