发布时间 : 星期五 文章电力系统不对称故障分析与计算更新完毕开始阅读df5a25ae9f3143323968011ca300a6c30c22f1d2
图5-5零序等值电路图
短路点K1零序标幺值为:
X30???X2?0??X3?0??//X4?0?//?X6?0??X7?0??//?X8?0??X9?0???0.128
短路点K1零序标幺值为:
X20??X2?0?//?X3?0???X4?0?//?X6?0??X7?0??//?X8?0??X9?0????0.400
K1点单相接地短路
?1?I3a1?1X31?X32?X30????1?1.934
0.221?0.168?0.128???1?IK?I3a?m?1?I3a1?3?1.934?5.803IK?IK?SB100?5.803??2.913?KA? 3UB3?115??KA?；SK?SBIKish?2.55?IK?2.55?2.913?7.4282?5.803?100?508.3?MV?A?
K2点两相短路：
X21????2?IK?Ib?Ic?m?2?I2a1?1.732?1.534?2.657
?IK?IK??2?I2a1?1?X22?1?1.534
0.339?0.313SB100?2.657??1.334?KA?；ish?2.55?IK?2.55?1.334?3.402?KA? 3UB3115?SK?SBIK?2.657?100?265.7?MV?A?
（二）：计算机程序法析与计算单相接地短路和两相短路时情况下：短路电流，冲击电流以及短路容量：
1. 由式,得到：
K11??1?10%?110/115?1.05；K??1?10%?110/115?1.05；
22?1?5%?10/10.5?1?5%?10/10.52. 正序导纳标幺值Y矩阵
Y矩阵的形成：正序电抗标幺值和对地电容标幺值的等值电路图如图5-6所示：
图5-6正序电抗标幺值和对地电容标幺值的等值电路图
正序导纳矩阵如下： 对地导纳式如下（5-1）：
Y20.0?Y20\.0Y21.0?Y21\.0Y22.0?Y22\.0111152??Y????2.92?10?6?100?0.019 22100111152??Y????2.97?10?6?100?0.020 22100111152??Y????2.97?10?6?50?0.010 22100其中，是图5-6节点1—3得对地导纳之半，，分别为节点3—5，3—6的导纳之半【9】.Y矩阵的元素为：
;Y21??y12y??j1.45;Y22?y22.0?21?y23??j4.754 2k11k22y34?y35?y36??j19.116; 2y22 ；Y24?Y25?Y26?Y27?0;Y31?0;y30?y20.0?y21.0?y22.0?0.049；
Y32??y23?j3.39;Y33?y30?y32?Y34??;
y34； ?j5.7;Y35??y35?j3.44;8；
k22Y66?
y67?y63?y22.0??j7.9; 2y33??????Y?1????????
j6.424j1.4500000j1.4500?j4.754j3.390j3.39?j19.116j5.70j5.7?j10.80j3.448000j6.897000?000??j3.448j6.8970??000? （5-1） ?j3.600??0?j7.9j0.99?0j0.99?j0.95??000
3 负序阻抗Y矩阵
图5-7负序阻抗标幺值和对地电纳标幺值的等值电路图
同理的得：如图5-7负序阻抗标幺值和对地电纳标幺值的等值电路图， 及负序导纳矩阵如下式如下（5-2）：
???j6.424j1.4500000??j1.45?j4.754j3.390000??0j3.39?j19.116j5.7j3.448j6.8970??Y?2????00j5.7?j10.8000????00j3.4480?j6.285400??00j6.89700?j7.9j0.99????00000j0.99?j0.95??3. 零序列Y矩阵：同理零序列电抗标幺值的等值电路图如图5-8所示：
图5-8所示零序列电抗标幺值的等值电路图
及负序导纳矩阵如下如下式（5-3）：
??0000000??0?j2.513j1.130000??0j1.13?j0j1.149j2.30??Y????100?0000000??? ?00j1.1490?j1.98300??00j2.300?j3.330????0000000??
5-2）（5-3） （
4 求不对称短路电流及相关参数：由式3-19及3-21节相关知识，运用高斯消去程序【10】
解得：
K1点单相接地短路时的转移阻抗为如下（5-4）：
?Z13?1???j0.0526??Z???j0.233223?1??????Z33?1???j0.3046????? ?Z43?1????j0.1607?; ?Z13?2???j0.036?8?Z13?0???0??Z???1?Z???j0.039?j0.16323?2??????23?0?????Z33?2???j0.213?0?Z33?0????j0.127?????????ZZ?;?j0.11240?43?2?????43?0????; （5-4） ??Z53?1???j0.2917??Z?????Z53?2???j0.116?9?Z53?0???j13?63?1???j0.3058??Z????9????0.050??63?2???j0.2Z63?0???j0.060?Z73?1?????j0.3187????73?2?????j0.222??9??Z73?0?????Z?0??K2点两相短路时的转移阻如下式（5-5）：
??Z12?1???j0.0913???Z??Z12?1??22?1??Z???j0.4045?????22?2???j0.0792??j0.2495????Z12?0???0?Z?Z??22?0?j0.380??32?1???j0.??Z??Z?j0.1631??Z??32?2???32?0???42?1???2332?j0.1231? ????;?Z?42?2??????j0.0861??;??Z?42?0?????j0.039??0??; ?Z52?1???Z???j0.2234?.2342??Z52?2???j0.0895??Z52?0??62?1???j0?Z??j0.1638????????j0.022?62?2???Z?62?0???j0.027?72?1????Z??j0.2441?????Z72?2?????j0.1707????Z72?0?????0??由式表（3-1）相关公式得： K1点单相接地短路
I?1?133?X33?1??X33?3??X?1j0.3046?j0.2130?j0.1275??j1.956
33?0?；I?BK?ISK3U?5.868?1003?115?2.943?KA? Bish?2.55?IK?2.55?2.943?7.5047?KA?; S?S?KB?IK?5.868?100?586.8?MV.A?;
K2点两相短路:
I?2?22?1X?1j0.2495??j1.529；;
22?1??X22?2?j0.4045?I??I?I2??2?Kbc?m?I2a1?1.732?1.529?2.648；I?SBK?IK3U?2.648?1003?115?1.329?KA?; BiM?2.55?IK?2.55?1.329?3.389?KA?;
SS?K?B?IK?2.648?100?264.8?MV?A?;
程序流程图如下：
5-5） （