0.1S时:If G220,0.1?1.11?3?175/0.85?10.711KA;
3?373?175/0.85?10.904KA;
3?370.2S时:If G220,0.2?1.13?1S时:If G110,1?1.31?3?175/0.85?12.640KA;
3?373?175/0.85?13.219KA;
3?373?175/0.85?13.412KA;
3?372S时:If G220,2?1.37?4S时:If G220,0?1.39?
5、短路点d5
0.0710.110d50.65510.65000.2140.214 合并串并联支路
0.0710.110d510.8640.288 (5)、转移电抗计算
①、110kV系统对短路点d5的转移电抗:
XS110f?0.110;
②、220kV系统对短路点d5的转移电抗:
XS220f?0.071?1?1.071;
③、连接在110kV母线上的发电机组对短路点d5的转移电抗:
XG110f?0.864;
④、连接在220kV母线上的3台发电机组对短路点d5的转移电抗:
XG220f?0.288?1?1.288;
(2)计算电抗:
220kV系统和110kV系统较发电机可以看做无穷大功率电源处理,直接计算其对的短路点d5电流;
①、连接在110kV母线上的发电机组对短路点d5的计算电抗:
XG110js?0.864?175/0.85?0.1779;
10003?175/0.85?0.7955;
1000②、连接在220kV母线上的3台发电机组对短路点d5的计算电抗:
XG220js?1.288?(11)短路电流标幺值
①、110kV系统对短路点d5的短路电流:
Is110??1?9.0909; 0.1101?0.9337; 1.071②、200kV系统对短路点d5的短路电流:
Is220??③、连接在110kV母线上的发电机组对短路点d5的短路电流:
查《电力工程电气设计手册·电气一次》手册第137页Xjs?0.1779可知:
IG220,0?6.13;IG220,0.1?4.33;IG220,0.2?4.10;IG220,;1?3.61IG220,2?3.30;IG220,4?3.02;
④.连接在220kV母线上的3台发电机组对短路点d5的短路电流: 查《电力工程电气设计手册·电气一次》手册第137页Xjs?0.7955可知:
IG220,0?1.34;IG220,0.1?1.27;IG220,0.2?1.29;IG220,1?1.50;IG220,2?1.62;IG220,4?1.64;
(12)短路电流有名值 电流基准值:IB?SB1000??5.026KA 3UB3?115短路点d5时110kV系统送至的短路点d5电流:
IfS110?9.0909?5.026?45.727;
短路点d5时220kV系统送至的短路点d5电流:
IfS220?0.9337?2.513?2.346;
连接110kV系统发电机送至d5点的短路电流:
0S时:If G110,0?6.13?175/0.85?6.344KA;
3?115175/0.85?4.481KA;
3?115175/0.85?4.243KA;
3?1150.1S时:If G110,0.1?4.33?0.2S时:If G110,0.2?4.10?1S时:If G110,1?3.61?175/0.85?3.736KA;
3?115175/0.85?3.4151KA;
3?115175/0.85?3.125KA;
3?1152S时:If G110,2?3.30?4S时:If G110,4?3.02?连接2200kV系统发电机送至d5点的短路电流: 0S时:If G220,0?1.34?3?175/0.85?4.160KA;
3?1153?175/0.85?3.943KA;
3?1153?175/0.85?4.005KA;
3?1150.1S时:If G220,0.1?1.27?0.2S时:If G220,0.2?1.29?1S时:If G110,1?1.50?3?175/0.85?4.657KA;
3?1153?175/0.85?5.029KA;
3?1153?175/0.85?5.091KA;
3?1152S时:If G220,2?1.62?4S时:If G220,0?1.64?