某学校供配电设计

毕业设计I摘要本次设计题目为某市实验中学供配电系统设计，该系统通过降压变压器与10kv公共电源干线相连，然后向学校供给电能。该校对供电可靠性要求也较高。因此，必须采用可靠性较高的接线形式。本次设计主要内容包括：负荷计算、短路电流计算、电气主接线的设计、电气设备的选择与校验（包括主变压器的选择、断路器及隔离开关的选择与校验、导体的选择与校验、电流互感器的选择与校验、电压互感器的选择和避雷器的选择等）和变配电所的布置与结构设计。其中，主接线代表了变配电所主体结构，它对各种电气设备的选择、配电装置的布置、继电保护、自动装置和控制方式的拟定都有决定性的关系，并将长期影响电力系统运行的可靠性、安全性、灵活性和经济性。在设计的过程中，本人参阅了大量的供配电系统设计、变配电所设计、建筑电气设计规范等相关的规范和设计手册，最后对该校供配电系统进行了初步设计。本设计为毕业设计，其目的是通过设计实践，综合运用所学知识，理论联系实际，锻炼独立分析和解决电气设计问题的能力，为未来的工作奠定坚实的基础。关键词：变压器电气主接线电气设备继电保护毕业设计IIAbstractThisdesigntopicisthepowersupplyanddistributionsystemforaexperimentalhighschoolofAcity,thissystemisconnectedwiththepubliclineof10kVthroughstep-downtransformers,anddistributeelectricalpowertoexperimentalhighschoolofAcity.TheexperimentalhighschoolofAcityelectricalchargeisbig,andtheschool’demandofreliabilityofpowersupplyishigh,usingthehighreliablewiringform.Thisdesignmaincontentincludes:thechargecomputation,short-circuitcurrentcomputation,electricalmainwiringdesign,electricalequipmentchoiceandverification(includingmainvoltagetransformerchoice,circuitbreakeranddisconnectingswitchwithcheck-up,conductorchoicewithcheck-up,currenttransformerchoicewithcheck-up,voltagetransformerchoicewithcheck-upandlightningprotectorchoiceandsoon),thedisposalandconfigurationofthetransformersubstationdesign.Betweenthem,theelectricalmainwiringhasrepresentedthemainbodiesstructureofthesubstation,ithasthedecisiverelationsabouttheelectricalequipmentchoice,thepowerdistributionequipmentarrangement,therelayprotection,thedecisionofautomaticdeviceandthecontrolmode,andithaslong-terminfluenceaboutthereliability，security，flexibilityandefficiencyoftheelectricalpowersystemmovement.Inordertofinishthedesign,Ireferringtothepowersupplyanddistributiondesignstandard,thetransformersubstationdesignstandard，theelectricaldesignstandardofarchitectureandsoon,carryonthepreliminarydesigntothispowersystem.Thisdesignisagraduationdesign.Thepurposeofthisdesignistogiveusachanceofsyntheticalusageoftheknowledgewehavelearned.Besides,itcantrainourabilitytoanalyzeandsolvepracticalproblemsinConstructelectricityindependentlysothatthetheoryisconnectedwithpracticeandasolidbaseismadeinfavoroffuturework.Keywords:transformer,electricalmainwiring,electricalequipment，relayprotection毕业设计i目录摘要Abstract第1章绪论..................................................................11.1供配电设计的意义和要求...............................................11.2供配电设计必须遵循的一般原则.........................................11.3设计步骤.............................................................21.4本次设计的主要工作...................................................4第2章系统计算负荷及无功功率补偿...........................................52.1负荷计算.............................................................52.1.1负荷计算的内容和目的...........................................52.1.2计负荷的确定...................................................52.1.3按需要系数法确定计算负荷的公式.................................62.1.4负荷计算的结果.................................................62.2无功功率补偿及其计算.................................................92.2.1无功补偿的目的.................................................92.2.2无功功率的人工补偿装置.........................................92.2.3并联电容器的选择计算方法......................................102.2.4无功功率补偿的计算............................................10第3章变配电所位置和主变压器及主接线方案的选择............................123.1变配电所位置的选择..................................................123.1.1变配电所型式的概述............................................123.1.2变配电所位置选择的一般原则....................................133.2负荷中心的确定......................................................133.3变电所主变压器的选择................................................143.3.1变电所主变压器选型的原则......................................143.3.2变电所主变压器台数的选择......................................143.3.3变电所主变压器容量的选择......................................143.4变配电所主接线方案的选择............................................153.4.1变配电所主接线设计要求........................................153.4.2变配电所主接线方案的拟定......................................17第4章短路电流计算.........................................................204.1计算短路电流的目的..................................................204.2短路计算的方法......................................................204.3标么值法计算短路电流................................................204.3.1标么值的概念..................................................204.3.2电力系统各元件电抗标么值的计算................................214.3.3用标么值法进行短路计算的方法..................................214.4短路电流的计算过程与结果............................................22第5章变配电所一次设备的选择校验...........................................255.1一次设备选择与校验的条件与项目......................................25毕业设计ii5.1.1一次设备选择与校验的条件......................................255.1.2一次设备选择与校验的项目......................................255.2一次设备选择依据....................................................265.2.1按正常工作条件选择............................................265.3一次侧设备的选择校验................................................295.3.110KV侧一次设备的选择校验.....................................295.3.2380V侧一次设备的选择校验....................................325.4高低压母线的选择..................