光伏电站短路电流计算书

XXXXXX光伏发电工程短路电流计算书审 查:校 核:编 写:一、工程概况XXXXXXX光伏发电工程总装机50MWp,海拔高度约为1215m。本工程建成后出1回110kV线路接入1XXXXX变110kV狈叽线路长约5.1km,选用LGJ-300型导线，变压器分列运行。二、技术参数1、110kV线路侧短路电流Imax=5.23kA主变压器B容量S=50000kVA,U=10.5%,110/35kVTOC\o"1-5"\h\zB1 k35kV厂变B容量S=160kVA,U=6%,35/0.4kVB1 kSVG变压器B容量S=10000kVA,U=7.5%,35/10kVB1 k5、联合单元箱式变压器BN容量SBN=1000kVA（分裂变压器），Uk=6.5%,36.75/0.315/0.315kV,分裂系数Kf=3.5,半穿越阻抗X'l-2=12%常用基准值：U(kV)j1153710.50.40.315I(kA)j0.51.565.5144.30183.29三、系统阻抗图厂变四、短路电流计算已知系统短路电流lx=5.23kAmaxXx=I/Ix=0.5/5.23=0.0956* j max线路采用LGJ-300导线，线路电抗取Xl=0.4l=5.1kmXl二X*Sj/Uj2=0.4*5.1*100/1152=0・0154*X*=00956+0.0154=0.111k短路电流Ikl=I/X=0.5/0.111=4.5kA1j*主变压器B1X=U%/100X100/S=10.5/100X100/50=0.21TOC\o"1-5"\h\zB1k B1则k点短路电流为：I=1/(X+X)=1.56/(0.111+0.21)=4.86kAk2j *B135kV厂变B2X=U%/100X100/S=6/100X100/0.16=37.5B2k B2则k点短路电流为：2I=I/(X+X)=144.30/(0.111+0.21+37.5)=3.815kAkB2j *B1SVG变压器B3X=U%/100X100/S=7.5/100X100/10=0.75B3k B2则k点短路电流为：3I=I/(X+X)=5.5/(0.111+0.21+0.75)=5.135kAkB3j *B1(4)联合单元箱式变压器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%则低压侧两支路电抗分别为：X2=X'2=1/2Xf=l/2X22.4%=11.2%高压侧支路电抗为：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仅考虑单一支路短路时短路电流为：IB=I/(X+X+X+X)=183.29/(0.111+0.21+0.8+11.2)=14.876kAkNj *B11 2

表6-1短路电流计算结果表短路点母线名称三相短路电流（kA）XXXX变llOkV母线5.23XXXX光伏电站110kV母线K14.5XXXX光伏电站35kV母线K2