、短路電流計(jì)算OMVA,略去"力取基準(zhǔn)容量5=1OMVA,略去"力U『115KV,lj=0.502A富興變:地區(qū)電網(wǎng)電抗Xi=Sj/Sdx=lj/ldx=0.502/15.94=0.0315km線路電抗X2=X*L*(S)/Up2)發(fā)電機(jī)電抗 發(fā)電機(jī)電抗 X3二（X發(fā)電機(jī)電抗 X3二（X=0.4*5*(100/1152)=0.015d發(fā)電機(jī)電抗 X3二（X16km線路電抗X4=X*L*(516km線路電抗X4=X*L*(50.4*16*(100/1152)=0.0495.6km線路電抗X5二X*L*(Sj/Up2)四、穿墻套管選擇CWWL-10 3150/2，額定彎曲破壞負(fù)荷8KN動穩(wěn)定檢查 8.62*(0.6+1)/0.4*44.962*10-2=697Nv0.6*8=4.8kN五、接地網(wǎng)110KV為有效接地系統(tǒng)，接地電阻規(guī)定《0.5。(1)既有接地裝置計(jì)算土壤電阻率p=cpp>o 令po=3*lC)4*1.2。.cm則p=360。.cm設(shè)人工接地體，采用垂直接地體與水平接地體構(gòu)成的復(fù)式接地裝置的電阻原地網(wǎng)Rt=l/(n*nc/Rc+ns/Rs)其中心=[p/(2nI)]*ln*(4L/0.84b)=[3.6*104/(2n*250)]*ln[(4*250)/(0.84*5)]=23*5.5=126.5n=100根Rs=[p/(2nI)]*ln(8L2/nbh)=360/(2n*800)*ln[(8*8002)/(n*0.04*0.8)]=1.24六、既有避雷針保護(hù)范疇計(jì)算現(xiàn)下洋變有四支等高避雷針(相對站內(nèi)地面標(biāo)高)，位置詳見B992C-D0101-03o令hx=10m,RiJrx=(1.5h-2hx)p=(l.5x30-2x10)=25hoab=h-D/7p=30-60/7=21.43m則A、B兩針間高度為hX=10m水平面上保護(hù)范疇的一側(cè)bxab=1.5ho-2hx=1.5*21.43-2*10=12.1同理h0Bc=h-D/7=30-50/7=22.85m貝ijbXBc=1.5h0-2hx=1.5*22.85-2*10=14.28mh°cd=h-D/7=30-50/7=22.85m則bXCD=1.5*22.85-2*10=14.28mhoAD=h-D/7=30-22.5/7=26.79m則bxcd=1.5*26.79-2*10=25.19m110kV變電站升壓改造計(jì)算書（電氣部分）b)=(10.5/100)*(100/31.5)=0.333(Ud%/100)*(Sj/Seb)=0.272X9=X1+X2=0.046Xi1=Xlo+X6=O.046C〔二Xlo/X9=O.935Xig/Xg=O.074]/C]=0.376/0.935=0.4026/0.074=5.0831.5MVA變壓器電抗X6(Ud%/100)*(Sj/Se50MVA變壓器電抗X二X8=X3+X4+X5=0.578X10=(X8*X9)/(X8+X9)地區(qū)電網(wǎng)支路日勺分布系數(shù)發(fā)電機(jī)支路的分布系數(shù)貝ljX13-X-1X14=X11/C2=0.371、求點(diǎn)的短路電流1.1求富興變供應(yīng)d1'點(diǎn)（即dl點(diǎn)）的短路電流+0.015)=10.913kA1〃=Sj/(X1+X2)=100/(0.031+0.015)=2173.913MVAichxi=V2*KchV=72*1.8*10.913=27.776kAIch=lxff+2(Kch-1)2=10.913*V1+2(1.8-I)2=10,913*1.51=16.479kA1.2求沙縣城關(guān)水電站供應(yīng)dl，點(diǎn)的短路電流將發(fā)電機(jī)支路日勺等值電抗換算到以發(fā)電機(jī)容量為基準(zhǔn)容量時的標(biāo)幺值Xjs=X8*Srg/Sj=0.578*48/100=0.277查表得，=3.993I*o.2=3.O96 1*4=3.043時額定電流:Up)=48/(1.732x115)=0.241求得：-'=I*''*lef=3.993x0.241=0.962kAIf0.2''=l*o.2''*lef=3.096x0.241=0.746kAIfO.4''-I*/'*Ief=3.043x0.241=0.732kAi *Kch=V2*1.8*0.962=2.448kA1.3求得cM'點(diǎn)的短路電流lx〃=10.913+0.962=11.875kA?=27.776+2.448=30.224kAlch=ll.875Vl+2*(1.8-1)2=17.93kA2、求d2點(diǎn)的短路電流1〃=lj/(X1+X2+X6)=5.50/(0.031+0.015+0.333)khx=khx=2*Kch*Ich=Ix〃Ml+2(51)2=14.5ch=Ix〃Ml+2(51)2=14.51.8*14.512=36.936kA12*Vl+2(1.8-1)2ch=Ix〃Ml+2(51)2=14.5=21.913kA3、求d2'點(diǎn)的短路電流3.1求富興變供應(yīng)d2'點(diǎn)的短路電流.=lj/X13=5.5/0.402=13.68kAichxi=V2*Kch*lx〃=V21.8*13.68=34.82kAIch=lx"Vl+2(KCh-1)2-13.68*%/l+2(1.8-I)2=20.656kA3.2求沙縣城關(guān)水電站供應(yīng)d2，點(diǎn)日勺短路電流將X14換算到以發(fā)電機(jī)容量為基準(zhǔn)容量時日勺標(biāo)幺值Xjs=X14*Srg/Sj=5.08*48/100=2.438查表得|*一=0.425I*o,2=O.431 1*4=0.431換算到115kV下發(fā)電機(jī)的額定電流：lef=Srg/(3Up)=48/(1.732xl0.5)=2.64求得：If''=I*''*lef=0.425x2.64=1.122kAlf0.2''=I*0.2''*原=0.431x2.64=1.138IfJ'=I/'兔尸0.431x2.64=1.138kA3.3求得d2,點(diǎn)的短路電流lx"=13.68+1.122=14.802kAich=1.414xl.8x14.802=37.674kAlch=l4.802Vz1+2*(1.8-1)2=22.35kA同理：求得終期d2點(diǎn)的短路電流1x2〃=Ij/(Xi+X2+X=5.50/(0.031+0.015+0.272)=17.3kAichx=V2*1.8*17.3^44kAlch=lxff*V1+2(Kch-l)2=17.3*Vl+1.28=26.122kA求得終期d25點(diǎn)的短路電流Ix〃=16.32+1.344=17.664kAich=l.414x1.8x17.664=44.96kAlch=lx〃V1+2*(1.8-1)2=26.655kA二、10KV母線選擇(銅13720N/cm2,鋁6860N/cm2)據(jù)最大長期工作電流選擇TMY-2(100*10)時母線水平放置,環(huán)境溫度為25°C時，載流量I=3248*0.9=2923A>1.05*2749=2886A(系數(shù)取0.9)檢查熱穩(wěn)定VQ/C^VI2t/c=717.6642*1.5/171=126.5mm2<(2*1000)mm2檢查動穩(wěn)定短路電動力 f=17.248*(l/a)*ich2*B*10-2=17.248*[(1.3*102)/(0.25*102)]*44.962*1CT?=1809.76N產(chǎn)生應(yīng)力Ox-x=M/W=fl/10w=(1809.76*130)/(10*33.3)二707N/cm2<13720N/cm2[ 若是單片矩形導(dǎo)體日勺機(jī)械應(yīng)力。=M/W=f1/lOw=(1809.76*130)/(10*16.7)=1408.8N/cm2<1372ON/cm2]求得絕緣子最大容許跨距1=(7.614/ich)*\/aco(j=(7.614/44.96)*,40*33.3*13720=754cm求導(dǎo)體片間作用力 Ox=fx2-2/hb2其中fx=9.8*kx*(ich2/b)*l0-2=9.8*0.12*(44.9671)*10-2=23.77N導(dǎo)體片間臨界跨距l(xiāng)ef=1.77* *b*4Vh/fx=1.77*65*V10/23.77=92cm本工程取40cm則ox=(23.772*402)/(102*1)=9040.2N/cm2〈銅13720N/cm2a=ax-x+crx=707+9040.2=9747.2N/cm2〈銅13720N/c