考虑杆塔等效半径变化的高杆塔雷击暂态特性分析

分析雷击输电线路杆塔时的暂态特性,对输电线路上电气设备的绝缘配合设计具有重要的指导意义。在国内外已有波阻抗杆塔模型的基础上,考虑高杆塔主体和呼高部分随高度的减小而等效半径增大,使得各部分波阻抗值减小的情况,对高杆塔进行细分,仿真研究高杆塔多波阻抗模型的分段数对雷电波传播的影响。通过比较和分析不同段时雷电流波形、雷电流幅值及接地电阻对杆塔雷击暂态特性影响,得出若对高杆塔主体进行细分段,则有其上过电压降低,暂态过程较长的结论。

Analysis on the High Transmission Tower's Transient Characteristic Caused by Lightning Stroke Considering the Impact of Equivalent Radius

The transient process caused by lightning stroke to the top of high transmission tower is of great importance in the design of the application of the transmission line, line insulator and arrester. In this paper the existing surge impedance models for transmission towers home and abroad are introduced in brief, to improve the model, on this basis the tower body is divided into different pieces, considering the impact of equivalent radius and then analysis the influence of lightning propagation. Through the contrastive analysis of the segments of the tower, the lighting current waveform, and the amplitude of lighting current, and surge impedance effect on the transient characteristic of the tower, combining theoretical analysis, from which we can find that the subdivision of the tower will reduce the overvoltage and prolong the transient process. The conclusion is available for reference to the design of high transmission tower.