年度股东大会

前言电能是社会主义建设和人民生活不可缺少的重要资源，电力工业在国民经济中占有十分重要的地位，电能时有发电厂供给，因为考虑经济原因，发电厂大多建在动力资源比较丰富的地方，而这些地方又远离大中型城市和工厂企业，这样需要远距离输送，经过升降压变电所进行转接，在进一步的将电能分配给用户和生产企业。由于电力电能的重要特点是不能储存，因此电力电能的生产、输送、分配和使用是同时进行的，于是电力电能从生产到使用构成一个整体，称为电力系统。对电力系统运行的基本要求：1.保证供电的可靠性电力系统的中断将使生产停顿，生活混乱，甚至危机人身和设备的安全运行，造成十分严重的后果，给国民经济带来严重的损失，因此，对电力系统的运行首先要保证供电的可靠性。2.保证良好的电能质量3.提高系统运行的经济性4.保证电力系统安全运行课程设计：一、设计题目某机械厂降压变电所的电气设计二、设计要求要求根据本厂所能取得的电源及本厂用电负荷的实际情况，并适当考虑到工厂生产的发展，按照安全可靠、技术先进、经济合理的要求，确定变电所的位置与型式，确定变电所主变压器的台数与容量、类型，选择变电所主接线方案及高低压设备和进出线，确定二次回路方案，选择整定继电保护装置，确定防雷和接地装置，最后按要求写出设计说明书，绘出设计图纸。三、设计依据1.工厂总平面图图1工厂总平面图2.工厂负荷情况工厂多数车间为两班制，年最大负荷利用小时为6800小时，日最大负荷持续时间为8小时。该厂除特种电机分厂、实验站为一级负荷，铸造分厂、锅炉房属二级负荷外，其余均属三级负荷。低压动力设备均为三相，额定电压为380V。电气照明及家用电器均为单相，额定电压为220V。本厂的负荷统计资料如表1所示。3.供电电源情况按照工厂与当地供电部门签订的供用电协议规定，本厂可由离厂5km和8km（0.4欧姆/km）两处的35kV的公用电源干线取得工作电源。干线首端所装设的断路器断流容量为800MVA，该电源的走向参看工厂总平面图。表1工厂负荷统计资料厂房编号厂房名称负荷类型设备容量/kW额定电压/kV功率因数costan需要系数dk1成品试验站动力1＃50002＃20001＃102＃0.380.82-0.871.370.5-0.6照明6-120.381.000.5-0.62电机制造分厂动力7200.380.6-0.681.170.18-0.25照明6-121.000.7-0.93新品制造分厂动力8800.380.6-0.71.160.2-0.3照明5-101.000.7-0.94特种电机分厂动力5800.380.65-0.721.230.65-照明5-101.000.65-0.75铸造分厂动力2900.380.6-0.71.020.5-0.6照明6-121.000.7-0.96锻造分厂动力5000.380.62-0.681.170.3-0.35照明5-11.000.7-0.97原材料分厂动力2700.380.63-0.721.170.3-0.36照明4-81.000.7-0.98机加工分厂动力3800.380.6-0.651.120.22-0.32照明5-101.000.7-0.99线圈制造厂动力4200.380.6-0.71.170.2-0.3照明6-121.000.7-0.910锅炉房动力600.380.8-0.91.050.6-0.8照明3-51.000.7-0.911生活区照明6000.380.9-1.00.50.7-0.84.气象条件本厂所在地区，年最热月平均最高气温为35°C，最热月平均气温为18°C，最热月地下0.8m处平均气温为30°C。5.地质水文资料本厂所在地区平均海拔500m，地层以砂粘土为主，地下水位为2m。6.电费制度本厂与当地部门达成协议，在工厂变电所高压侧计量电能，设专用计量柜，按两部电费制缴纳电费。每月基本电费按主变压器容量为18元/KVA，动力电费为0.9元/kWh，照明电费为0.52元/kWh。工厂最大负荷时的功率因数不得低于0.9，此外，电力用户需按新装变压器容量计算，一次性向供电部门缴纳供电贴费6～10kV为800元/KVA。目录1.负荷计算和无功功率补偿···················································41.1负荷计算·······························································41.2无功功率补偿···························································62.变电所位置和型式选择·····················································83.变电所主变压器台数和容量、类型的选择·····································84.变电所主接线方案的设计···················································94.1装设一台主变压器的主接线方案·········································94.2装设两台主变压器的主接线方案·········································105.短路电流的计算···························································115.1计算电路·····························································115.2短路计算基准值·······················································115.3确定元件电抗标幺值···················································115.4短路点相关计算·······················································126.变电所一次设备的选择和校验···············································136.110kv侧一次设备的选择校验·············································136.2380v侧一次设备的选择和校验··········································146.3高低压母线的选择·····················································157.变电所进出线的选择和校验·················································157.110kv高压进线的选择···················································157.2380v低压出线的选择··················································167.3作为备用电源的高压联络线的选择校验···································188.变电所二次回路方案的选择及继电保护的整定·································208.1变电所二次回路方案的选择··············································208.2变电所继电保护装置···················································208.3装设电流速断保护·····················································218.4作为备用电源的高压联络线的继电保护装置·······························219.防雷保护与接地装置的设计·················································229.1变电所的防雷保护······················································229.2接地装置的设计························································2310．.附录一参考文献·························································2411.变压器主接线图···························································251．负荷计算和无功功率补偿1.1负荷计算1.1.1单组用电设备计算负荷的计算公式a)有功计算负荷（单位为KW）30P=dKeP，dK为系数b)无功计算负荷（单位为kvar）30Q=30Ptanc)视在计算负荷（单位为kvA）30S=cos30Pd)计算电流（单位为A）30I=NUS330,NU为用电设备的额定电压（单位为KV）1.1.2多组用电设备计算负荷的计算公式a)有功计算负荷（单位为KW）30P=ipPK30式中iP30是所有设备组有功计算负荷30P之和，pK是有功负荷同时系数，可取0.85~0.95b)无功计算负荷（单位为kvar）30Q=iqQK30，iQ30是所有设备无功30Q之和；qK是无功负荷同时系数，可取0.9~0.97c)视在计算负荷（单位为kvA）30S=230230QPd)计算电流（单位为A）30I=NUS330经过计算，得到各厂房和生活区的负荷计算表，如表1.1所示表1.1厂方编号厂方名称负荷类别计算负荷功率因素cosθtanθ需要系数Kd30P(KW)30Q(kva)S30(kva30I(A))1成品试验站动力30001200411016445088203529330910.82～0.871.370.5～0.6照明10.8010.8281.000.7～0.92电机制造分厂动力180210.62777280.6～0.681.170.18～0.25照明10.8010.8281.000.7～0.93新品制造分厂动力26430644111600.6～0.71.160.2～0.3照明909231.000.7～0.94特种电机分厂动力40649964316920.65～0.721.230.65～0.7照明909231.0007～0.95铸造分厂动力1741772481430.6～0.71.020.5～0.6照明10.8010.8281.000.7～0.96锻造分厂动力1752042681540.62～0.681.170.3～0.35照明909231.000.7～0.97原材料分厂动力971131483890.63～0.721.170.3～0.36照明7.207.2181.000.7～0.98机加工分厂动力121.61361821050.6～0.651.120.22～0.32照明909231.000.7～0.99线圈制造分厂动力1261471931110.6～0.71.170.2～0.3照明10.8010.8281.000.7～0.910锅炉房动力4850.469400.8～0.91.050.6～0.8照明4.504.5111.000.7～0.911生活区照明480048012630.9～1.00.50.7～0.8表1.230P(KW)30Q(kva)S30(kvA)30I(A)一次侧30004110508850.88二次侧3351.7348748367348.7表1.330P(KW)30Q(kva)S30(kvA)30I(A)功率因数一次侧5