杆塔基础外敷螺旋接地装置的冲击散流优化研究及其应用

Impact Dispersion Optimization of Externally Applied Spiral Grounding Device for Pole Tower Foundation

为有效降低高压输电线路杆塔接地装置的雷电冲击接地电阻,本研究充分利用杆塔基础的垂直空间,采用一种螺旋状接地装置沿杆塔基桩表面敷设直至基桩底部,在更大限度散泄冲击电流的同时降低水平外延射线的铺设难度。研究了冲击接地电阻的原理及其在CDEGS软件仿真计算中的实现方法,并对计算方法进行了可靠性验证。建立考虑雷电流冲击下的土壤非线性电离的接地模型,研究不同雷电流幅值、土壤电阻率下螺旋接地装置的冲击特性,从而进行螺旋结构的优化选择;以110 kV输电杆塔典型四角放射型接地网为原型,对比计算双层土壤下杆塔基础外敷螺旋装置前后所需外延射线的长度,分析杆塔基础外敷螺旋接地装置的应用效果,为螺旋接地装置的推广使用提供理论基础以及方法参考。

In order to effectively reduce the lightning impact grounding resistance of the grounding device of the high-voltage transmission line tower,the author makes full use of the vertical space of the tower foundation,and uses a spiral grounding device to be laid along the surface of the tower foundation pile to the bottom of the foundation pile,reduce the difficulty of laying horizontal epitaxial rays while dissipating the impulse current to a greater extent.Introduce the principle,method and verification of CDEGS software to calculate impulse ground resistance,and establish a grounding model that considers soil nonlinear ionization under lightning current impulse,and explore spiral grounding devices under different lightning current amplitudes and soil resistivities.Based on the typical design of the four-corner radiation of 110 kV power transmission towers as a prototype,compare and calculate the length of the extension rays required before and after the spiral device of the tower foundation under the double soil layer,and analyze the spiral grounding device of the tower foundation.The application effect of the spiral grounding device provides a theoretical basis and method reference for the popularization and use of the spiral grounding device.