基于平面复合降阻材料的杆塔基础接地降阻研究

杆塔基础自然接地作为输电线路重要的接地装置,能减少外延接地及降阻施工成本。针对特高压输电线路杆塔基础接地提出基于平面复合降阻材料的塔基外敷接地降阻策略,首先,采用CDEGS仿真计算软件建立特高压杆塔单根浇注桩接地计算模型,分析均匀土壤、多层土壤、混合土壤三种条件下的外敷接地降阻效果;然后,通过单个塔基外敷计算模型分析外敷材料不同敷设方式的降阻效率;最后,计算完整杆塔基础外敷接地降阻效率和散流分布特征,并与水平人工外延接地降阻方式进行对比。结果表明,外敷接地降阻效率与土壤条件、敷设位置等因素有关,在高土壤电阻率条件下,塔基外敷接地降阻效率超过22%,与水平人工外延接地相比,塔基外敷接地降阻的散流比超过96%,接地材料利用率高,可减少征地和二次接地施工成本。

Research on Grounding Resistance Reduction of Tower Foundation Based on Planar Composite Resistance Reducing Material

The natural grounding of the tower foundation serves as an important grounding device for the transmission line, which can reduce the construction cost of the epitaxial grounding and the resistance reduction. In this paper, a grounding resistance reduction strategy based on planar composite resistance reducing material is proposed for the foundation grounding of UHV transmission line towers. Firstly, the CDEGS simulation calculation software is used to establish the grounding calculation model of the single-casting pile of UHV tower. The grounding resistance reduction effect of externally applied soil under three conditions of uniform soil, multi-layer soil and mixed soil. Then, the single-base external calculation model is used to analyze the resistance reduction efficiency of different laying methods of external coating materials. Finally, the grounding resistance reduction efficiency and scattered distribution of external foundation of the complete tower foundation are calculated. Compared with horizontal artificial epitaxial grounding resistance, the results show that the external grounding resistance reduction efficiency is related to soil conditions and laying position. Under the condition of high soil resistivity, the grounding resistance efficiency of the tower base is more than 22%, and the external application of the tower base, the grounding resistance is more than 96%, and the grounding material utilization rate is high, which reduces the construction cost of the land acquisition and secondary grounding.