复杂电力网络短路电流分布及地网分流系数

Fault Current Distribution and Current Division Factor of Grounding Grid in Complex Power System Network

为改进电力系统短路故障电流的计算,将变压器的相分量模型与传统相分量法相结合,在此基础上提出了连接有任意回输电线路(包括架空线路和地下电缆)的变电站发生接地短路时故障电流分布和地网分流系数的计算方法,并开发了相应的计算软件FCDFGS。通过软件计算与现场实测的比较,验证了测量方法的正确性与计算模型的合理性。对影响地网分流系数的主要因素进行计算、比较和分析,结果表明靠近变电站10～15个档距的参数对其影响很大,且各参数在达到一定值后,地网分流系数呈现"饱和效应"。最后提出了降低地网入地短路电流的技术措施。

Based on the combination of the phase-coordinate model of transformer and the traditional phase-coordinate method,a calculation method of fault current distribution and current division factor of grounding grid is put forward when ground short circuit takes place within substation,which is connected with numbers of transmission lines（including overhead lines and underground cables）,and the corresponding calculation software FCDFGS is developed.With comparison of the results of software calculation and field measurement,the validity of the calculation model and correctness of the measurement method are verified,and the factors which have effect on current division factor of grounding grid are analyzed.The results show that current division factor of grounding grid presents saturation effect,and the parameters within the first 10 to 15 towers neighboring the substation are the most remarkably effective.Finally,technical measures to reduce grounding grid fault current are also brought forward.