光伏电站短路电流计算书.docx

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⑵5m本工程建成后出1回UOkV线路接入1XXXXX变HOkV侧线路长约5.1km,选用LGJ-3OO型导线，变压器分列运行二、技术参数1、UOkV线路侧短路电流Imax = 5.23kA2、主变压器B 容量S =50000kVA, U =10. 5%, 110/35kV、1Blk3、35kV 厂变B 容量S =160kVA, U =6%, 35/0. 4kV2Blk4、SVG 变压器B 容量S =10000kVA, U =7. 5%, 35/10kV 3Blk5、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'1-2 = 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IKlfcVo o o厂受57送压器进缴降合单元四、短路电流计算(1)系统短路电流lx =5. 23kA maxXx=I /lx =0. 5/5. 23=0. 0956* jmax线路采用LGJ-300导线，线路电抗取X1R.4 1=5. 1kmXI =X*Sj/Uj2=0. 4*5. 1*100/1152=0. 0154 *X*=0. 0956+0. 0154=0. IllkAkAk 短路电流Ikl = I/X =O.5/o. ui=4.5 ij *(2)主变压器B1X =U%/1OOX1OO/ S =10. 5/100X100/50=0.21 Bl kBl那么 k 点短路电流为：I =1 /( X+ X )=1. 56/(0. 111+0.21)=4. 86kA 2k2 j * Bl(3) 35kV 厂变B2X =U%/l00X100/ S =6/100X100/0.16=37.5B2 kB2那么k点短路电流为： 2I =1 /( X+ X )=144. 30/(0. 111+0. 21+37. 5)=3. 815kA k B2 j * Bl(4) SVG变压器B3X =U%/l00X100/ S =7. 5/100X100/10=0.75B3 kB2那么k点短路电流为： 3I =1 /( X+ X )=5. 5/(0. 111+0. 21+0. 75)=5. 135kA k B3 j * Bl(4)联合单元箱式变压器B N阻抗图Xl-2=X'l-2/(l+ Kf/4)=12%/(l+3. 5/4) =6. 4%Xf=Kf - Xl-2 = 3. 5X6. 4%=22. 4%那么低压侧两支路电抗分别为：X2 =X'2=l/2 Xf= 1/2X22. 4%=11.2%高压侧支路电抗为：Xl= (1- Kf/4) XI-2= (1- 3.5/4) X6. 4%=0.8%折 合 到 100MVA Xl=0. 8%X 100/1=0. 8, X2 =11. 2%X 100/1=11. 2仅考虑单一支路短路时短路电流为：IB =1/( X+X +X +X )=183. 29/(0. 111+0. 21+0. 8+11. 2)=14. 876kAk N j * Bl 12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UOkV母线5.23XXXX光伏电站UOkV母线K14.5XXXX光伏电站35kV母线K24.86XXXX光伏电站35kV厂变低压侧KB23.815XXXX光伏电站SVG变低压侧KB35.135XXXXX光伏电站箱变低压侧KBN14.876。