110kv降压变电站的一次系统初步设计

2011年5月湖南工业大学本科生毕业设计（论文）I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。本论文中待设计的变电站是一座降压变电站，在系统中起着汇聚和分配电能的作用，担负着向该地区工厂、农村供电的重要任务。该变电站的建成，不仅增强了当地电网的网络结构，而且为当地的工农业生产提供了足够的电能，从而达到使本地区电网安全、可靠、优质、经济地运行的目的。本论文《110kV某市变电站一次系统设计》，首先通过对原始资料的分析及根据变电站的总负荷选择主变压器，同时根据主接线的经济可靠、运行灵活的要求，选择了两种待选主接线方案进行了技术比较，淘汰较差的方案，确定了变电站电气主接线方案。其次进行短路电流计算，从三相短路计算中得到当短路发生在各电压等级的母线时，其短路稳态电流和冲击电流的值。再根据计算结果及各电压等级的额定电压和最大持续工作电流进行主要电气设备选择及校验（包括断路器、隔离开关、电流互感器、电压互感器等）。最后，做了防雷保护、继电保护、并绘制了电气主接线图。关键词：变电站，降压，电气设备湖南工业大学本科生毕业设计（论文）IIABSTRACTPowersystemsubstationasanimportantpartoftheentirepowersystemdirectlyaffectsthesafetyandeconomicoperation.Tobedesignedinthispaperisastep-downsubstationinthesystemplaystheroleofaggregationanddistributionofelectricenergy,chargedwiththefactorytotheregion,theimportanttaskofruralelectrification.Thecompletionofthesubstationwillnotonlystrengthenthelocalpowergridnetworkstructure,butalsoforthelocalindustrialandagriculturalproductionprovidesenoughpower,sothattheregionalpowergridsoastoachievesafe,reliable,quality,aimtoruntheeconomy.Inthisthesis,110kVsubstationcityprimarysystemdesign,firstthroughtheanalysisofrawdataandselectedbasedontotalloadofthesubstationmaintransformer,themainwiringunderbotheconomicalandreliable,flexibleoperationrequirements,selectthemainconnectionofthetwotobeelectedAtechnicalcomparisonprogram,outofpoorprogramtodeterminethemainelectricalsubstationconnectionprogram.Second,theshort-circuitcurrentcalculation,obtainedfromthethree-phaseshortcircuitcalculationoccurswhenshort-circuitthevoltagelevelofthebus,itssteady-statecurrentandtheimpactofshort-circuitcurrentvalue.Accordingtotheresultsandthevoltagelevelofvoltageandmaximumcontinuousoperatingcurrentofthemainelectricalequipmentselectionandvalidation(includingcircuitbreaker,disconnectingswitch,currenttransformer,voltagetransformer,etc.).Finally,themaindrawoftheelectricalwiringdiagram,electricalgenerallayoutplans,withlightningprotection.Keywords：Powersystemsubstation,step-downsubstation,electricalequipment湖南工业大学本科生毕业设计（论文）III目录第1章设计内容和任务.......................................11.1原始资料分析......................................................11.1.1变电站的建设规模..............................................11.1.2电力系统与本所的连接情况......................................11.1.3计算负荷的确定................................................21.2设计原则和基本要求................................................31.3设计内容..........................................................3第2章主变压器的选择.......................................42.1主变台数的确定.........................................................................................................42.2本变电站站用变压器的选择.....................................................................................7第3章电气主接线的选择.....................................83.1选择原则..........................................................83.1.1主接线设计的基本要求及原则....................................83.1.2主接线的基本形式和特点........................................93.2变电站的各侧主接线方案的拟定.....................................103.2.1110KV侧主接线方案............................................103.2.235KV侧主接线方案.............................................123.2.310KV侧主接线方案.............................................13第4章短路电流计算........................................154.1短路电流计算的主要目的...........................................154.2短路电流计算的假设...............................................154.2.1进行以下数据的计算...........................................154.2.2三相短路瞬态过程中某一时刻短路电流周期分量有效值的计算。.....154.3短路电流计算的一般规定...........................................154.4短路电流计算步骤.................................................164.5短路点的设置原则.................................................174.6网络参数标么值计算...............................................174.6.1网络参数及基准值计算.........................................174.6.2取基准值.....................................................17湖南工业大学本科生毕业设计（论文）IV4.6.3各元件参数标么值计算.........................................174.6.4短路点的选择和等值网络图.....................................184.6.5最大运行方式下三相短路电流计算...............................184.6.6最小运行方式下三相短路电流计算...............................204.6.7三相对称短路电流计算结果汇总表...............................21第5章导体和电气设备的选择................................225.1电气设备的选择原则...............................................225.2按短路情况校验...................................................235.3断路器和隔离开关的选择...........................................265.4互感器的选择.....................................................305.5母线的选择.......................................................325.6高压熔断器的选择.................................................36第6章变电站防雷保护......................................396.1变电所的保护对象.................................................396.2电工装置的防雷措施...............................................396.3本设计的防雷保护方案.............................................41第7章继电保护............................................437.1继电保护部分配置.................................................437.1.1主变压器、线路的保护和自动装置...............................43结论......................................................45参考文献..........................................