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110kV变电站设计计算书

计算书目录第一章负荷资料的统计分析 (2)第二章短路电流的计算 (4)第一节最大运行方式下的短路电流计算 (4)第二节最小运行方式下的短路电流计算 (10)第三章主要电气设备的选择及校验 (18)第一节设备的选择 (18)第二节隔离开关的选择 (20)第三节导线的选择 (22)第四节互感器的选择 (24)第四章布置形式 (26)第一章负荷资料的统计分析一、10KV侧供电负荷统计S10=(1.6+1.4+2.6+0.5+2.2+1.02+1.2+4.00)×1.05×0.9/0.85=16142.82KVA二、35KV侧供电负荷统计S35=(5+6+5+6)×1.05×0.9/0.85=24458.82KVA三、所用电负荷统计计算负荷可按照下列公式近似计算:所用电计算负荷S=照明用电+生活区用电+其余经常的或连续的负荷之和×0.85(KVA)根据任务书给出的所用负荷计算:S所用=(3.24+3.24+4.5+2.7+1.1+2.5+9.7+10+20+4.5+5+10.6)×0.85/0.85=77.08KVA四、110KV供电负荷统计S110=(S10 +S35 +S所用)×1.05=(16142.82+24458.82+77.08)×1.05=42712.66KVA五、主变压器的选择经计算待设计变电所的负荷为42712.66KVA。

单台主变容量为Se=∑P*0.6=42712.66*0.6=25627.59KVA六、主变型式确定选用传递功率比例100/100/5035KV侧输送功率为31500×0.8=25200KW≥31796.5×0.8×0.5×1.15=14626.39KW经比较合理10KV侧输送功率为31500×0.8×0.5=12600KW≥18677.6×0.8×0.5×1.15=8591.7KW经比较合理因此,三绕组变压器选用传递功率比例100/100/50SFS7-31500/110三绕组变压器参数:额定容量:31500KVA额定电压:110±2×2.5%/38.5±2×2.5%/11KV连接组别:YN,yn0,d11空载损耗:46kW 短路损耗:175kW空载电流:1.0%阻抗电压:Uk1-3%=17 Uk2-3%=6 Uk1-2%=10.5七、经济比较计算综合投资Z:Z=Z0(1+a/100) =1.9 Z0 (万元)计算年运行费用U:U=a*△A*10+U1+U2 = 2△A+0.08Z(万元)式中:U1——小修、维护费,一般为(0.022-0.042)本次设计取0.022Z(变电工程)U2——折旧费,一般为(0.005-0.058)Z,本次设计取0.058Z。

(变电工程) a——电能电价,由各省市实际电价确定。

本次设计取0.20元/KW〃h △A——变压器年电能损失总值(KW〃h)第二章短路电流的计算(运行方式:根据系统运行方式,110KV电站不是电压枢纽点,没有特殊调压要求;另外,有部分系统功率由110KV电网经过变电站送到35KV变电站。

设系统的最大运行方式为:电厂机组满发,各电源短路容量为最大;系统的最小运行方式为:电厂容量不变,其余2个电源的最小短路容量为最大短路容量的75%。

)一、最大运行方式下的短路电流计算1、选取基准功率Sj =100MVA;基准电压Uj= Up计算各元件参数的标么值:(1)110KV系统变电所及进线X 1*=1/(Sx/SB)+X0LSB/Uav2=100/533+0.4×9×100/1152=0.215 Sx=533MVA等值电路:(2)110KV火电厂及进线发电机阻抗计算:X G1*=SBXG%/100SN=0.11*100*0.85/25=0.374X G2*=XG3*=SBXG%/100SN=0.15×100×0.85/12=1.063变压器阻抗计算:X T1*= SBUd%/100SN=10.5/31.5=0.333已知T2,T3参数: Ud1-2%=10.5, Ud1-3%=17,Ud2-3%=6,则Ud1%=1/2(Ud1-2%+Ud1-3%-Ud2-3%)=10.75Ud2%=1/2(Ud1-2%+Ud2-3%-Ud1-3%)=-0.25Ud3%=1/2(Ud1-3%+Ud2-3%-Ud1-2%)=6.25X 1T1= X2T1= SBUk1%/100SN=10.75/31.5=0.341X 1T2= X2T2= SBUk2%/100SN=-0.25/31.5=-0.008X 1T3= X 2T3= S B Uk 3%/100S N =6.25/31.5=0.198 则 X T2*=X T3*=0.341+(-0.008)=0.333 14KM 线路阻抗计算:X *=X 1L 1S B /Uav 2=0.4×14×100/1152=0.042 等值电路:*******简化后的等值电路:X 2*=0.707//1.396//1.396+0.042=0.393(3)35KV 变电站及进线X 3*=1/(S 1/S B )+X0LS B /Uav 2=100/300+0.4×5×100/372=0.479 S x =300MVA 等值电路:3(4)所选出的SFS7-31500/110型变压器阻抗计算:变压器参数:U 1—2%=10.5 ;U 1—3%=17;U 2—3%=6Ud1%=1/2(Ud1-2%+Ud1-3%-Ud2-3%)=10.75 Ud2%=1/2(Ud1-2%+Ud2-3%-Ud1-3%)=-0.25≈0 Ud3%=1/2(Ud1-3%+Ud2-3%-Ud1-2%)=6.25X 4*= U d1%/100 ×S j /S n =10.75/100×100/63=0.171 X 5*=0X 6*= U d3%/100 ×S j /S n =6.25/100×100/63=0.099两台变压器并联的等值电路:645(5) 短路电流计算等值电路图及短路点选择:645d 1点短路电流计算:110KV 基准电流:I j =S j /√3U j =100/1.732×115=0.502KA a.110KV 变电站侧提供的电流:I (3)dz*=1/ X 1*=1/0.215=4.651KA 短路电流的有名值:I (3)dz = I (3)dz*〃I j =4.651×0.502=2.335KA K ch 取1.8冲击电流: I (3)ch =2.55I (3)dz =2.55×2.335=5.954KA 电流最大有效值:I ch =1.51×I (3)dz =1.51×2.335=3.526KA短路容量:S (3)d = I (3)dz* S j =4.651×100=465.1MVAb.110KV 火电厂侧提供的电流: I (3)dz*=1/ X 1*=1/0.393=2.545 短路电流的有名值:I (3)dz = I (3)dz*〃I j =2.545×0.502=1.277KA K ch 取1.8冲击电流: I (3)ch =2.55I (3)dz =2.55×1.277=3.256KA电流最大有效值:Ich =1.52×I(3)dz=1.52×1.277=1.941KA短路容量:S(3)d = I(3)dz*Sj=2.545×100=254.5 MVAc.35KV变提供的电流:I(3)dz*=1/(X3*+X4*+X5*)=1/(0.479+0+0.171)=1.538短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.538×0.502=0.772KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×0.772=1.969KA电流最大有效值:I ch =1.51×I(3)dz=1.51×0.772=1.166KA短路容量:S(3)d = I(3)dz*Sj=1.538×100=153.8MVA(6)、d2点短路电流计算:35KV 基准电流:Ij =Sj/1.732Uj=100/1.732×36.75=1.571KAa.110KV变电站侧提供的电流:I(3)dz*=1/(X1*+X4*+X5*)=1/0.386=2.591短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.571×2.591=4.070KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×4.070=10.379KA电流最大有效值:Ich =1.51×I(3)dz=1.51×4.070=6.146KA短路容量:S(3)d = I(3)dz*Sj=2.591×100=259.1MVAb.110KV火电厂侧提供的电流: I(3)dz*=1/ (X2*+X4*+X5*)=1/0.564=1.773短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.773×1.571=2.785KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×2.785=7.102KA电流最大有效值:Ich =1.52×I(3)dz=1.52×2.785=4.233KA短路容量:S(3)d = I(3)dz*Sj=1.773×100=177.3MVAc.35KV变提供的电流:I(3)dz*=1/X3*=1/0.479=2.088短路电流的有名值:I(3)dz = I(3)dz*〃Ij=2.088×1.571=3.280KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×3.280=8.364KA电流最大有效值:Ich =1.51×I(3)dz=1.51×3.280=4.953KA短路容量:S(3)d = I(3)dz*Sj=2.088×100=208.8 MVA(7)、d3点短路电流计算:10KV 基准电流:Ij =Sj/1.732Uj=100/1.732×10.5=5.499KAa.110KV变电站侧提供的电流:I(3)dz*=1/(X1*+X4*+X6*)=1/0.485=2.062短路电流的有名值:I(3)dz = I(3)dz*〃Ij=2.062×5.499=11.339KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×11.339=28.914KA电流最大有效值:Ich =1.51×I(3)dz=1.51×11.339=17.122KA短路容量:S(3)d = I(3)dz*Sj=2.062×100=206.2MVAb.110KV火电厂侧提供的电流:I(3)dz*=1/ (X2*+X4*+X6*)=1/0.663=1.508短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.508×5.499=8.292KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×8.292=21.145KA电流最大有效值:I ch =1.52×I(3)dz=1.52×8.292=9.467KA短路容量:S(3)d = I(3)dz*Sj=1.508×100=150.8 MVAc.35KV变提供的电流:I(3)dz*=1/(X3*+X6*)=1/0.578=1.730短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.730×5.499=9.513KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×9.513=24.258KA电流最大有效值:Ich =1.51×I(3)dz=1.51×9.513=14.365KA短路容量:S(3)d = I(3)dz*Sj=1.730×100=173 MVA计算参数表二、最小运行方式下的短路电流计算1、选取基准功率Sj =100MVA;基准电压Uj= Up计算各元件参数的标么值:(1)110KV变电站及进线X 1*=1/(Sx/SB)+X0LSB/Uav2=100/(533×0.75)+0.4×9×100/1152=0.277Sx=533×0.75=399.75MVA 等值电路:(2)110KV火电厂及进线发电机阻抗计算:X G1*=SBXG%/100SN=0.11*100*0.85/25=0.374X G2*=XG3*=SBXG%/100SN=0.15×100×0.85/12=1.063变压器阻抗计算:X T1*= SBUd%/100SN=10.5/31.5=0.333已知T2,T3参数: Ud1-2%=10.5, Ud1-3%=17,Ud2-3%=6,则Ud1%=1/2(Ud1-2%+Ud1-3%-Ud2-3%)=10.75Ud2%=1/2(Ud1-2%+Ud2-3%-Ud1-3%)=-0.25Ud3%=1/2(Ud1-3%+Ud2-3%-Ud1-2%)=6.25X 1T1= X2T1= SBUk1%/100SN=10.75/31.5=0.341X 1T2= X2T2= SBUk2%/100SN=-0.25/31.5=-0.008X 1T3= X2T3= SBUk3%/100SN=6.25/31.5=0.198则 XT2*=XT3*=0.341+(-0.008)=0.33314KM线路阻抗计算:X *=X1L1SB/Uav2=0.4×14×100/1152=0.042等值电路:*******简化后的等值电路:X 2*=0.707//1.396//1.396+0.042=0.393(3)35KV 变电站及进线X 3*=1/(S 1/S B )+X0LS B /Uav 2=100/(300×0.75)+0.4×5×100/372=0.590 S x =225MVA 等值电路:3(4)所选出的SFS7-31500/110型变压器阻抗计算:变压器参数:U 1—2%=10.5 ;U 1—3%=17;U 2—3%=6Ud1%=1/2(Ud1-2%+Ud1-3%-Ud2-3%)=10.75 Ud2%=1/2(Ud1-2%+Ud2-3%-Ud1-3%)=-0.25≈0 Ud3%=1/2(Ud1-3%+Ud2-3%-Ud1-2%)=6.25X 4*= U d1%/100 ×S j /S n =10.75/100×100/63=0.171 X 5*=0X 6*= U d3%/100 ×S j /S n =6.25/100×100/63=0.099两台变压器并联的等值电路:645(5) 短路电流计算等值电路图及短路点选择:645d 1点短路电流计算:110KV 基准电流:I j =S j /√3U j =100/1.732×115=0.502KA a.110KV 变电站侧提供的电流:I (3)dz*=1/ X 1*=1/0.277=3.610KA 短路电流的有名值:I (3)dz = I (3)dz*〃I j =3.610×0.502=1.812KA K ch 取1.8冲击电流: I (3)ch =2.55I (3)dz =2.55×1.812=4.621KA 电流最大有效值:I ch =1.51×I (3)dz =1.51×1.812=2.736KA短路容量:S (3)d = I (3)dz* S j =3.610×100=361MVAb.110KV 火电厂侧提供的电流: I (3)dz*=1/ X 2*=1/0.393=2.545 短路电流的有名值:I (3)dz = I (3)dz*〃I j =2.545×0.502=1.277KA K ch 取1.8冲击电流: I (3)ch =2.55I (3)dz =2.55×1.277=3.256KA电流最大有效值:Ich =1.52×I(3)dz=1.52×1.277=1.941KA短路容量:S(3)d = I(3)dz*Sj=2.545×100=254.5 MVAc.35KV变提供的电流:I(3)dz*=1/(X3*+X4*+X5*)=1/(0.590+0+0.171)=1.314短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.314×0.502=0.660KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×0.660=1.683KA电流最大有效值:Ich =1.51×I(3)dz=1.51×0.660=0.997KA短路容量:S(3)d = I(3)dz*Sj=1.314×100=131.4MVA(6)、d2点短路电流计算:35KV 基准电流:Ij =Sj/1.732Uj=100/1.732×36.75=1.571KAa.110KV变电站侧提供的电流:I(3)dz*=1/(X1*+X4*+X5*)=1/0.448=2.232短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.571×2.232=3.506KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×3.506=8.940KA电流最大有效值:Ich =1.51×I(3)dz=1.51×3.506=5.294KA短路容量:S(3)d = I(3)dz*Sj=2.232×100=223.2MVAb.110KV火电厂侧提供的电流: I(3)dz*=1/ (X2*+X4*+X5*)=1/0.564=1.773短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.773×1.571=2.785KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×2.785=7.102KA电流最大有效值:Ich =1.52×I(3)dz=1.52×2.785=4.233KA短路容量:S(3)d = I(3)dz*Sj=1.773×100=177.3MVAc.35KV变提供的电流:I(3)dz*=1/X3*=1/0.590=1.695短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.695×1.571=2.663KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×2.663=6.791KA电流最大有效值:Ich =1.51×I(3)dz=1.51×2.663=4.021KA短路容量:S(3)d = I(3)dz*Sj=1.695×100=169.5MVA(7)、d3点短路电流计算:10KV 基准电流:Ij =Sj/1.732Uj=100/1.732×10.5=5.499KAa.110KV变电站侧提供的电流:I(3)dz*=1/(X1*+X4*+X6*)=1/0.547=1.828短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.828×5.499=10.052K AKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×10.052=25.633KA电流最大有效值:Ich =1.51×I(3)dz=1.51×10.052=15.179KA短路容量:S(3)d = I(3)dz*Sj=1.828×100=182.8MVAb.110KV火电厂侧提供的电流:I(3)dz*=1/ (X2*+X4*+X6*)=1/0.663=1.508短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.508×5.499=8.292KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×8.292=21.145KA电流最大有效值:Ich =1.52×I(3)dz=1.52×8.292=9.467KA短路容量:S(3)d = I(3)dz*Sj=1.508×100=150.8 MVAc.35KV变电站提供的电流:I(3)dz*=1/(X3*+X6*)=1/0.689=1.451短路电流的有名值:I(3)dz = I(3)dz*〃Ij=1.451×5.499=7.979KAKch取1.8冲击电流: I(3)ch =2.55I(3)dz=2.55×7.979=20.346KA电流最大有效值:Ich =1.51×I(3)dz=1.51×7.979=12.048KA短路容量:S(3)d = I(3)dz*Sj=1.451×100=145.1 MVA计算参数表第三章主要电气设备的选择及校验一、设备的选择1、断路器的选择(一)110kV侧断路器的选择(1)、该回路为 110 kV电压等级,故可选用六氟化硫断路器。

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