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页数:15页
时间:2017-09-21
《虎石台220 60kv降压变电所电气部分初步设计 计算书》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第一章短路电流的计算1.1系统计算电路图和等值电路图取SB=100MVA,VB=Up,求得等值电路图中各阻抗标幺值如下:发电机1:X2=X4=Ud%/100×SB/S=12.4/100×100/200/0.85=0.0527变压器1:X3=X5=Xd%/100×SB/S=14/100×100/240=0.0583发电机2:X6=X8=X10=Ud%/100×SB/S=18/100×100/125/0.85=0.1224变压器:X7=X9=X11=Xd%/100×SB/S=10.5/100100/160=
2、0.0656线路:2×100KM:X’=1/2×100×0.4×100/2202=0.041360KM:X”=60×0.4×100/2202=0.0496X1=X+X=0.0413+0.0496=0.090948KM线路:X12=48×0.4×100/2202=0.03972×60KM线路:X13=1/2×60×0.4×100/2202=0.02482×100KM线路:X14=160×0.4×100/2202=0.041380KM线路:X15=80×0.4×100/2202=0.06611.2220KV
3、母线上K1点发生短路时的短路计算首先进行网络化简,化简后的网络图见图:X‘1=X*+X1=0.05+0.0909=0.1409X‘2=(X2+X3)/2=(0.0527+0.0583)=0.0555X‘3=(X6+X7)/3=(0.1224+0.0656)/3=0.0627X‘4=X12=0.0397X‘5=X13=0.0248X‘6=X15=0.0661X‘7=X14=0.0413进一步化简如下:对X’5X’6X’7进行三角变换网络见图1-4所示X”1=X’5X’7/(X’5+X’6+X’7)=0.0
4、248×0.0413/(0.0248+0.0661+0.0413)=0.00748X”2=X’6X’7/(X’5+X’6+X’7)=0.0661×0.0413/(0.0248+0.0661+0.0413)=0.02066X”3=X’5X’6/(X’5+X’6+X’7)=0.0248×0.0661/(0.0248+0.0661+0.0413)=0.01240网络见图1-5所示X‘=X1X2/X1+X2=0.1409×0.0555/(0.1409+0.0555)=0.03983X“=(X‘+X3)X4/(X
5、‘+X3+X4)=(0.03983+0.04742)×0.07507/(0.03983+0.04742+0.07507)=0.04035X#=X‘+X”=0.02066+0.04035=0.06101C3=X”/(X’+X3)=0.04035/(0.03983+0.04742)=0.46250C4=1-C3=1-0.4625=0.5375C1=C3X’/X1=0.4625×0.02066/0.14091=0.13072C2=C3-C1=0.4625-0.13072=0.33178X∈=0.06101X1
6、∈=X∈/C1=0.06101/0.13072=0.46674X2∈=X∈/C2=0.06101/0.33178=0.18389X4∈=X∈/C4=0.06101/0.5375=0.11351Xjs1=X1∈SG1/SB=0.46674×11000/100=51.3409Xjs2=X2∈SG2/SB=0.18389×200/0.85/100=0.43268Xjs4=X4∈SG3/SB=0.11351×125/0.85/100=0.16692X‘∈=X∈+1/2×(Ud%/100)×(100/S变)=0.
7、06101+(1/2)×(14.3/100)×(100/120000)=0.06107X‘1∈=X‘∈/C1=0.06107/0.13072=0.46719X‘2∈=X‘∈/C2=0.06107/0.33178=0.18407X‘4∈=X‘∈/C4=0.06107/0.5375=0.11362X‘js1=X1∈SG1/SB=0.46719×11000/100=51.39103X‘js2=X2∈SG2/SB=0.18407×200/0.85/100=0.43310X‘js4=X4∈SG3/SB=0.113
8、62×125/0.85/100=0.16709d1点短路有名值:I”(3)=1/Xjs1×SG1/Uav=1/51.34089×11000/×230=0.5378250s:I”d1(3)=I”+2.411×SG2/Uav+6.763×SG3/Uav=0.537825+(2.411×200×2+6.763×125×3)/0.85/(×230)=10.775900.6s:I”d1(3)=I”+1.872×SG2/Uav+3.359×SG3/Ua
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