输电线路杆塔辅助接地网降阻效率及影响因素研究

输电线路杆塔接地网能够有效降低接地网接地阻抗,保证雷击电流安全地流入大地,实际杆塔施工过程中存在地形受限、盲目施工、降阻效率低等问题。对此,采用防雷接地领域中的CDEGS软件建立双边、单边、方框、垂直4种辅助接地网形式,通过改变外延长度、电流频率、土壤电阻率及土壤结构等因素分析比较4种辅助接地网的散流特性和降阻效率,进而研究降阻效率的影响因素。计算结果表明,杆塔辅助接地网的降阻效率与外延引线长度及辅助接地网终端形式关系密切,并随不同频率电流作用呈现不同的变化趋势,土质及地形条件对辅助地网散流特性有影响。该结论可为复杂地形下输电线路设计与施工、杆塔接地改造提供参考。

Research on Resistance Reduction Efficiency and Influencing Factors of Transmission Lines Auxiliary Grounding Grid

The grounding grid of the transmission line tower can effectively reduce the grounding impedance of the grounding grid and ensure that the lightning strike current flows safely into the earth.In the actual tower grounding project,there are problems such as limited terrain,blind construction and low efficiency of reducing resistance.In this paper,the CDEGS software in the field of lightning protection and grounding is used to establish the four auxiliary grounding grids of bilateral,unilateral,square and vertical.By changing the factors of epitaxial length,grounding frequency,soil resistivity and soil structure,the scattered characteristics and the resistance reduction efficiency of the auxiliary grounding grid are analyzed,and the influencing factors of the resistance reduction efficiency are studied.The calculation results show that the efficiency of the tower-assisted grounding grid is closely related to the length of the epitaxial lead and the terminal form of the auxiliary grounding grid,and it shows a changing trend with different frequency currents.The soil quality and topographic conditions have an impact on the distribution characteristics of the auxiliary grounding grid.The conclusions of this paper can provide reference for the design and construction of transmission lines and the grounding reconstruction of towers under complex terrain.