机械加工车间低压配电系统及车间变电所设计

本科毕业设计（论文）题目：机械加工车间低压配电系统及车间变电所设计学生姓名学号教学院系专业年级指导教师职称单位辅导教师职称单位完成日期2011年06月9日摘要本设计是机械厂机加工车间的低压配电系统及车间变电所供电系统。本文首先进行了负荷计算，根据功率因数的要求在低压母线侧进行无功补偿，进而确定对主变器容量、台数，从经济和可靠性出发确定主接线方案。其次，通过短路电流计算出最大运行方式和最小运行方式下的短路电流，确定导线型号及各种电气设备。最后根据本厂对继电保护要求，确定相关的保护方案和二次回路方案。本设计采用需用系数法进行负荷计算，无功功率补偿采用低压侧电容并联补偿方法，这种方法能补偿低压侧以前的无功功率、经济效益比较好。根据机械加工车间用电特点和需求，主接线方案采用了高压侧无母线、低压侧单母线分段的主接线方案。根据干式变压器与油浸变压器在经济和安装条件对比，选择两台SC9-500/10系列干式变压器。在仔细研究各负荷的实际数据，并严格按照国家规定，依照以上设计步骤设计本供电系统设计方案，以到达提高生产效益的目的。关键词：低压配电系统；负荷计算；主接线；变电所；短路计算AbstractThisdesignisthefactorymachiningworkshopoflowvoltagedistributionsystemandworkshopsubstationpowersupplysystem.Thispaperconductedaloadcalculation,accordingtotherequirementsofpowerfactorinthelow-pressuresideofthebusreactivepowercompensation,andtodeterminethecapacityofthetransformerdevice,thenumberofunits,startingfromtheeconomicandreliabilitytodeterminethemainterminalprogram.Secondly,calculatethemaximumshortcircuitcurrentoperationmodeandminimumoperatingmodeoftheshortcircuitcurrenttodeterminethewiretypeandvarietyofelectricalequipment.Finally,accordingtothefactoryonprotectionrequirements,identifyrelevantprogramsandsecondarycircuitprotectionprogram.Thisdesignusestheneedcoefficientmethodfortheloadcalculation,reactivepowercompensationcapacitorinparallelwithlow-pressuresideofthecompensationmethod,thismethodcancompensateforlow-voltagesideofthepreviousreactivepower,economicefficiencyisbetter.Accordingtomachineshopcharacteristicsandneedsofelectricity,themainconnectionschemesusingnon-bushighside,lowsideofthesingle-bussectionoftheMainWiring.Accordingtodry-typetransformersandoilimmersedtransformersandinstallationconditionsintheeconomycomparedtoselecttwoSC9-500/10seriesofdry-typetransformers.Onlythencarefullystudiesthefactorytheactualdata,strictlystipulatedaccordingtothecountry,andonlythenmaydesignaneconomyreliablepowersupplysystemthroughtheabovedesignprocedure,thusarrivestheenhancementproductionbenefitthegoal.Keywords:LowVoltageDistributionSystem;LoadCalculation;MainConnection;Substation;Shortcircuitcalculation目录1绪论...............................................................................................................................11.1设计背景、目的及意义.....................................................................................11.2设计内容.............................................................................................................11.3设计原则.............................................................................................................12负荷计算及无功补偿...................................................................................................22.1负荷计算.............................................................................................................22.1.1负荷计算的方法及其适用范围...............................................................22.1.2需用系数法...............................................................................................22.1.3负荷确定...................................................................................................42.2无功功率补偿.....................................................................................................52.2.1无功功率补偿概念...................................................................................52.2.2无功补偿提高功率因数的意义...............................................................52.3无功补偿容量计算.............................................................................................62.3.1无功功率补偿方式选择...........................................................................62.3.2无功补偿容量的确定...............................................................................82.3.3补偿容量计算...........................................................................................93变电所主接线方案设计及变压器选择.....................................................................103.1变电所主变压器台数与容量选择...................................................................103.1.1选择主变压器台数时应考虑下列原则.................................................103.1.2主变压器的确定.....................................................................................113.2总配变电所的主接线方案比较选择...............................................................124短路电流的计算及一次设备的选择原则.................................................................144.1短路计算...........................................................................................................144.1.1短路电流计算目的.................................................................................144.1.2采用三相短路电流计算为标准的原因.................................................144.1.3短路电流计算的方法步骤.....................................................................144.1.4短路电流计算.........................................................................................154.2一次设备选择...................................................................................................164.2.1概述.........................................................................................................164.2.2一次设备的选择原则.............................................................................164.2.3按