kv变电站短路电流计算书

、短路电流计算取基准容量SplOOMVA,略去5Uj=l15KV,后0.502A富兴变：地区电网电抗Xi=Sj/Sdx=lj/ldx=0.502/15.94=0.0315km线路电抗X2=X*L*(S/Up2)=0.4*5*(100/1152)=0.015发电机电抗X3=(Xd,5%/100)*(Sj/Seb)=(24.6/100)*(100/48)=0.51216km线路电抗X4=X*L*(Sj/Up2)=0.4*16*(100/1152)=0.0495.6km线路电抗X5=X*L*(Sj/Up2)=0.4*5.6*(100/1152)=0.01731.5MVA变压器电抗X6=X7=六、既有避雷针保护范畴计算现下洋变有四支等高避雷针（相对站内地面标高），位置详见B992C-D0101-03o令hx=10m,贝ij1二（1.5h-2hx）p=（l.5x30-2x10）=25h0AB=h-D/7p=30-60/7=21.43m则A、B两针间高度为hx=10m水平面上保护范畴时一侧bxAB=l.5ho-2hx=1.5*21.43-2*10=12.1同理h0Bc-h-D/7=30-50/7=22.85m则bXBc=l.5h0-2hx=l.5*22.85-2*10=14.28mh0cD=h-D/7=30-50/7=22.85m贝bXCD=1.5*22.85-2*10=14.28mM=h-D/7=30-22.5/7=26.79m贝ijbXCD=1.5*26.79-2*10=25.19mllOkV变电站升压改造计算书（电气部分）(Ud%/100)*(S/Seb)=(10.5/100)*(100/31.5)=0.33350MVA变压器电抗X=(Ud%/l00)*(Sj/Seb)=0.272X8=X3+X4+X5=0.578X9=X]+X2=0.046X10=(X8*X9)/(Xs+X9)Xn=Xlo+X6=O.O46地区电网支路的分布系数C]=X10/X9=0.935发电机支路的分布系数C2=X1o/X8=O.O74贝ijX13=Xn/Ci=0.376/0.935=0.402X14二X"C2=0.376/0.074=5.081、求dl，点的短路电流求富兴变供应dl，点(即dl点)的短路电流lx 〃=lj/(Xi+X2)=0.502/(0.031+0.015)=10.913kA=Sj/(X1+X2)=l00/(0.031+0.015)-2173.913MVA*1.8*10.913=27.776kAlCh=lxz，Ml+2(Qh-l)2=10.913*V1+2(1.8-1)2=10.913*1.51=16.479kA求沙县城关水电站供应点的短路电流将发电机支路时等值电抗换算到以发电机容量为基准容量时的标幺值Xjs=X8*Srg/S『0.578*48/100=0.277查表得I*''=3.9931*0,2=3.096 1*4=3.043换算到115kV下发电机的额定电流：lef=Srg/(3Up)=48/(1.732x115)=0.241求 得 ：F'二「*33.993x0.241=0.962kAlf0.2''-l*o.2''*lef=3.096x0.241=0.746kAlf0.4'‘二I*/'*lef=3.043x0.241=0.732kAichf=M2KhT〃 =，2*1.8*0.962=2.448kA求得dl，点的短路电流lx〃=10.913+0.962=11.875kAich=27.776+2.448=30.224kAlch=11.875M 1+2*(1.8-1K=17.93kA2、求d2点的短路电流lx 〃=lj/(X1+X2+X6)=5.50/(0.031+0.015+0.333)=14.512kAi—O* V*1 "Ichx-N 、ch1x2=2*1.8*14.512=36.936kAlch=lxffVl+2(Kch-l)2=14.512*V1+2(181)2=21.913kA3、求d2,点的短路电流求富兴变供应d2,点日勺短路电流1〃=lj/X]3=5.5/0.402=13.68kA1尸72K/x〃=M2*1.8*13.68=34.82kA1+2(1.8-1)2=20.656kA求沙县城关水电站供应d2,点的短路电流将X14换算到以发电机容量为基准容量时时标 幺 值Xjs=X14*Srg/Sj=5.08*48/100=2.438查表得I*''=0.4251*0.2=0.431 1*4=0.431换算到115kV下发电机的额定电流：原二Srg/(3Up)=48/(1.732x10.5)=2.64求 得 ：-'二I*''*lef=0.425x2.64=1.122kAlf0.2''=1*。2''*扇=0.431x2.64=1.138M'二1/'*lef=0.431x2.64=1.138kA求得d2,点时短路电流ich=1.414x1.8x14.802=37.674kAlch=14.802M 1+2*(1.8-1K=22.35kA同理：求得终期d2点的短路电流L〃=li/(X1+X2+X6)=5.50/(0.031+0.015+0.272)=17.3kALhx=M2*1.8*17.3=44kAlch=lxz，*Vl+2(Kch-l)2=17.3*M1+1.28=26.122kA求得终期d2,点日勺短路电流lx〃=16.32+1.344=17.664kAich=1.414x1.8x17.664=44.96kAlch=lx〃V1+2*(181)2=26.655kA二、10KV母线选择(铜13720N/cm2,铝6860N/cm2)据最大长期工作电流选择TMY-2(100*10)时母线水平放置，环境温度为25℃时，载流量I=3248*0.9=2923A>1.05*2749=2886A(系数取0.9)检查热稳定VQ/C^V\2]/c=V]7.6642*1.5/171=126.5mm2<(2*l000)mm2检查动稳定短路电动力仁17.248*(I/O)*ich2*B*10-2=17.248*[(1.3*102)/(0.25*102)]*44.962*10-2=1809.76N产生应力ax.x=M/W=f1/10w=(1809.76*130)/(10*33.3)=707N/cm2<13720N/cm2[ 若是单片矩形导体日勺机械应力o=M/W=fl/10w二(1809.76*130)/(10*16.7)二1408.8N/cm2<l3720N/cm2 ]求得绝缘子最大容许跨距l=(7.614/ich)*v/acoa二(7.614/44.96)*M40*33.3*l3720=754cm求导体片间作用力。x=fx2*lc7hb2其 中fx=9.8*kx*(ich2/b)*10-2=9.8*0.12*(44.9671)*10-2=23.77N10/23.77=92cm本工程取40cm则ox=(23.772*402)/(i02*l)=9040.2N/cm2〈铜13720N/cm2o=ox-x+Ox=707+9040.2=9747.2N/cm2<铜13720N/cm2按机械共振条件拟定最大容许跨距(共振35-155HZ)l2=(112V£)/f=(l12*2.89*11400)/155=23800=>l=154cm本工程取1=1300mm三、支柱绝缘子选择手册P25510KV选ZS-35/8 (8*0.6=4.8kN)Fc=0.173*(lc/a)*ich2=0.173*(1.3/0.4)*44.962=1135.9N<4.8KN四、穿墙套管选择CWWL-103150/2,额定弯曲破坏负荷8KN动 稳 定 检 查8.62*(0.6+l)/0.4*44.962*10-2=697N<0.6*8=4.8kN五、接地网110KV为有效接地系统，接地电阻规定《0.5。(1)既有接地装置计算土壤电阻率p=cpPo 令P0=3*1。4*1.2。.cm则p=3600.cm设人工接地体，采用垂直接地体与水平接地体构成的复式接地装置的电阻原地网Rt=l/(n*nc/Rc+ns/Rs)其中Rc=[p/(2nl)]*ln*(4L/0.84b)=[3.6*104/