杆塔接地网跨越公路路基接地散流特性与行人安全防护

Grounding Dispersing Characteristics and Pedestrian Safety Protection ofTower Grounding Grid Crossing Highway Subgrade

针对城镇人口密集区输电杆塔与公路临近时接地网散流特性及公路路面跨步电压分布问题,本研究建立杆塔接地网及公路路基模型,研究公路路基宽度、主接地网与公路间距离和辅助接地网形式对接地网分流系数及跨步电压的影响,并提出为跨越公路路基接地体添加绝缘层的防护措施。研究结果表明:公路路基宽度的增加使得接地网分流系数降低及路面跨步电压增大;随着频率的改变,主接地网与公路之间距离对接地网接地特性影响不同;垂直型辅助接地网与其他辅助接地网形式相比受公路路基影响最小;跨越公路路基接地体添加绝缘层后降低路面跨步电压效果比较明显。研究结果可为城镇输电线路杆塔接地装置的设计提供参考。

Aiming at the dispersion characteristics of grounding grid and the step voltage distribution of highway pavement when the transmission tower is close to the highway in densely populated urban areas.Firstly,the tower grounding network and highway subgrade model are established.Then,the influences of road subgrade width,distance between main grounding network and highway and auxiliary grounding network on the splitter coefficient and step voltage are studied.Finally,the protective measures of adding insulation layer for grounding body of roadbed crossing highway are put forward.The results show that the increase of subgrade width reduces the shunt coefficient of the grounding network and increases the step voltage of the road surface.With the change of frequency,the influence of the distance between the main grounding network and the road on the grounding characteristics of the docking network is different.Com⁃pared with other auxiliary grounding nets,the vertical auxiliary grounding nets are least affected by road subgrade.The effect of reducing the step voltage of the pavement is obvious after adding insulating layer to the grounding body across the highway subgrade.The research results can provide reference for the de⁃sign of tower grounding device of urban transmission line.