基于电磁暂态程序的架空地线分流系数的计算

为了准确计算变电站接地网接地短路电流和架空地线的分流系数,以某500 kV输电系统为例,采用电磁暂态程序(the alternative transient program-electormagnetic transient program,ATP/EMTP)对系统中各主要元件进行建模,计算变电站内、外发生单相接地故障时短路电流的分布和架空地线的分流系数,分析变电站接地网接地电阻、杆塔接地电阻、地线型号、线路长度、变电站外短路位置等对其接地短路电流和地线分流系数的影响,得出接地网电阻、杆塔接地电阻增大,出线回路数减少时,接地短路电流增大,架空地线的分流系数减小的结论。

Calculation on Shunt Coefficient of Overhead Ground Wire Based on EMTP

For precise calculation on ground short circuit current and shunt coefficient of overhead ground wire, some 500 kV transmission system is taken as an example for modeling every major element by means of the alternative transient programelectromagnetic transient program （ATP/EMTP）; distribution of short circuit current and shunt coefficient of overhead ground wire under circumstances of inward and outward single-phase ground faults of substations are calculated; impact of ground resistance of ground networks, ground resistance of poles and towers, types of ground wires, ground wire types, line lengths, short-circuit location out of the substation on ground short circuit current and shunt coefficient of overhead ground wire is analyzed） . The conclusion is reached that ground short circuit current rises and shunt coefficient of overhead ground wire is reduced in case ground network resistance and ground resistance of poles and towers increase and outgoing circuits decrease.