水电站短路电流计算 下载本文

2、短路点d6

0.0710.1100.655100.650d60.2140.214

合并串并联支路

0.0710.11010.2880.650d60.214

(6)、转移电抗计算

①、110kV系统对短路点d6的转移电抗:

XS110f?0.110?0.650?0.760;

②、220kV系统对短路点d6的转移电抗:

XS220f?0.071?1?0.650?1.721;

③、连接短路点d6的发电机组对短路点d6的转移电抗:

XG110f?0.214;

④、连接在220kV母线上的3台发电机组对短路点d6的转移电抗:

XG220f?0.288?0.650?1?1.938;

(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d6电流;

①、连接在220kV母线上的3台发电机组对短路点d6的计算电抗:

XG220js?1.938?3?175/0.85?1.197;

1000②、短路点d6连接发电机组对短路点d6的计算电抗:

XGjs?0.214?175/0.85?0.0441;

1000(13)短路电流标幺值

①、110kV系统对短路点d6的短路电流:

Is110??1?1.3158; 0.7601?0.5811; 1.721②、200kV系统对短路点d6的短路电流:

Is220??③、短路点d6连接发电机组对短路点d6的短路电流:

Is??1?4.673; 0.214④、连接在220kV母线上的3台发电机组对短路点d6的短路电流: 查《电力工程电气设计手册·电气一次》手册第138页Xjs?1.197可知:

IG220,0?0.88;IG220,0.1?0.86;IG220,0.2?0.88;IG220,1?0.97;IG220,2?0.97;IG220,4?0.97;

(14)短路电流有名值 电流基准值:IB?SB1000??36.701KA 3UB3?15.75短路点d6时110kV系统送至的短路点d6电流:

IfS110?1.3158?36.701?48.291;

短路点d6时220kV系统送至的短路点d6电流:

IfS220?0.5811?36.701?21.323;

短路点d6连接发电机组对短路点d6的短路电流:

IfS?4.673?36.701?171.534;

连接2200kV系统发电机送至d6点的短路电流: 0S时:If G220,0?0.88?3?175/0.85?19.948KA;

3?15.753?175/0.85?19.495KA;

3?15.753?175/0.85?19.948KA;

3?15.750.1S时:If G220,0.1?0.86?0.2S时:If G220,0.2?0.88?1S时:If G110,1?0.97?3?175/0.85?21.988KA;

3?15.753?175/0.85?21.988KA;

3?15.753?175/0.85?21.988KA;

3?15.752S时:If G110,2?0.97?4S时:If G110,4?0.97?

7、短路点d7

0.0710.1100.655100.6508.7300.2140.214d7

合并串并联支路

0.0710.11010.2880.6508.7300.214d7

(7)、转移电抗计算

①、110kV系统对短路点d7的转移电抗:

XS110f?0.110?0.650?8.730?9.490;

②、220kV系统对短路点d7的转移电抗:

XS220f?0.071?1?0.650?8.730?10.451;

③、连接短路点d7的发电机组对短路点d7的转移电抗: