ANALYSIS OF LIGHTNING SURGE IN SUBSTATION BY NEW SORGE

该项目旨在开发瞬态电磁场传播代码（TEPCO），可以用矩量法分析输电线路中的浪涌现象。该方法在同一时间范围内处理时间响应，并对雷涌中典型的非线性现象--线性电阻和电感元件闪络模型进行处理。为了验证该程序的正确性，我们在一个小型模型中通过实验研究了雷电波如何进入变电站，并注意到电力线电流、地线电流和门架电流之间的关系。如果我们在接地线和龙门架之间插入400 Ω电阻，变电站入口处电源线上的浪涌电流显示的峰值小于无电阻时峰值的一半。电源线电流与地线电流的流动方向相反。研究了双、三线接地情况下，接地线对防止逆闪络的倍增效应。在地线电流感应的作用下，三地线的电源线电流比双地线的电源线电流增加15%。然而，在三重之间的电压却相反地降低。因此，增加接地线是防止回闪的有效措施。由于输电线路的相对几何关系对雷电波的影响，在分析雷电波进入变电站时，必须考虑输电线路与龙门架之间的相互耦合。

The project aimed to develop the Transient Electromagnetic Field Propagation Code (TEPCO) which can analyze surge phenomena in transmission lines by Moment Method. The method deals the time response in same time range, and linear resistance and inductive element flashover model which is a typical nonlinear phenomena in lightning surge. To verify the code, we studied how the lightning surge travels into a substation by experimentally in a miniature model taking notice of the relations between the power line currents, ground wire currents and gantry currents. If we insert the resistance 400OMEGA between ground wire and gantry, the surge current on the power lines at the entry of the substation shows the peak value less than a half of the peak in the resistance free. The power line current flows in the opposite direction with the ground wire current. It is also investigated the multiplication effects of ground wire to prevent back flashover in case of double and triple ground wires. In the cause of the induction by the ground wire current, the power line current in triple ground wires increases 15% greater than the double ground wires. However, the voltage between are hones in triple decreases contrariwise. Therefore, the multiplication of ground wire is effective for the avoidance of back flashover. As the relative geometrical relations influence the lightning surge on the power lines, it is necessary to account the mutual coupling between the power lines and gantry in the analysis of the surge traveling into a substation.