光伏電站短路電流計(jì)算書

XXXXXX光伏發(fā)電工程短路電流計(jì)算書審 查:校 核:編 寫:一、工程概況XXXXXXX光伏發(fā)電工程總裝機(jī)50MWp,海拔高度約為1215m。本工程建成后出1回110kV線路接入1XXXXX變110kV狽嘰線路長約5.1km,選用LGJ-300型導(dǎo)線，變壓器分列運(yùn)行。二、技術(shù)參數(shù)1、110kV線路側(cè)短路電流Imax=5.23kA主變壓器B容量S=50000kVA,U=10.5%,110/35kVTOC\o"1-5"\h\zB1 k35kV廠變B容量S=160kVA,U=6%,35/0.4kVB1 kSVG變壓器B容量S=10000kVA,U=7.5%,35/10kVB1 k5、聯(lián)合單元箱式變壓器BN容量SBN=1000kVA（分裂變壓器），Uk=6.5%,36.75/0.315/0.315kV,分裂系數(shù)Kf=3.5,半穿越阻抗X'l-2=12%常用基準(zhǔn)值：U(kV)j1153710.50.40.315I(kA)j0.51.565.5144.30183.29三、系統(tǒng)阻抗圖廠變四、短路電流計(jì)算已知系統(tǒng)短路電流lx=5.23kAmaxXx=I/Ix=0.5/5.23=0.0956* j max線路采用LGJ-300導(dǎo)線，線路電抗取Xl=0.4l=5.1kmXl二X*Sj/Uj2=0.4*5.1*100/1152=0?0154*X*=00956+0.0154=0.111k短路電流Ikl=I/X=0.5/0.111=4.5kA1j*主變壓器B1X=U%/100X100/S=10.5/100X100/50=0.21TOC\o"1-5"\h\zB1k B1則k點(diǎn)短路電流為：I=1/(X+X)=1.56/(0.111+0.21)=4.86kAk2j *B135kV廠變B2X=U%/100X100/S=6/100X100/0.16=37.5B2k B2則k點(diǎn)短路電流為：2I=I/(X+X)=144.30/(0.111+0.21+37.5)=3.815kAkB2j *B1SVG變壓器B3X=U%/100X100/S=7.5/100X100/10=0.75B3k B2則k點(diǎn)短路電流為：3I=I/(X+X)=5.5/(0.111+0.21+0.75)=5.135kAkB3j *B1(4)聯(lián)合單元箱式變壓器BN

Xl—2=X'l—2/(l+Kf/4)=12%/(l+3.5/4)=6.4%Xf=Kf?X1—2=3.5X6.4%=22.4%則低壓側(cè)兩支路電抗分別為：X2=X'2=1/2Xf=l/2X22.4%=11.2%高壓側(cè)支路電抗為：Xl=(l-Kf/4)Xl-2=(1-3.5/4)X6.4%=0.8%折合到100MVAX1=0.8%X100/1=0.8,X2=11.2%X100/1=11.2僅考慮單一支路短路時短路電流為：IB=I/(X+X+X+X)=183.29/(0.111+0.21+0.8+11.2)=14.876kAkNj *B11 2

表6-1短路電流計(jì)算結(jié)果表短路點(diǎn)母線名稱三相短路電流（kA）XXXX變llOkV母線5.23XXXX光伏電站110kV母線K14.5XXXX光伏電站35kV母線K2