杆塔入地雷电流对周边鱼塘的影响及防护方法

Influence of Tower Grounding Lightning Currents on Surrounding Fish Ponds and Protective Measures

针对雷雨过后广东某地区杆塔附近鱼塘中出现不同鱼类大量死亡现象,对220 kV罗丹乙线的典型事故杆塔进行仿真建模,通过CDEGS软件验证模型正确性,研究鱼体长度及鱼体在电场中受流角度与鱼体电流密度关系,研究并分析杆塔周围土壤电阻率及鱼塘至接地装置距离对鱼的电磁影响。研究表明,鱼体越长,鱼体中心电流密度变化越小;受流角度越大,鱼体中心电流密度越小,角度为90°时最小;高土壤电阻率会增强电流向鱼塘散流的趋势,并增大鱼塘至接地装置距离对鱼体电流密度的影响。最后根据工程实际提出了屏蔽水平接地极并增设垂直接地极的改造方案。

In allusion to the phenomena of massive fish death in a pond near to the tower after thunderstorm in a certain area of Guangdong,this paper makes simulation and modeling for the accidental tower of 220 kV LuodanⅡline.It verifies accuracy of the model based on CDEGS software and studies relationships between fish body lengths and current flow angles of the fish in the electric field and current densities of the fish.Meanwhile,it analyzes electromagnetic influences of different surrounding soil resistivities and distances from the fish pond to the grounding device(thereafter as fish pond distances)on the fish.Corresponding research indicates as the length of fish increases,the center current density of fish changes smaller,and as the current flow angle becomes larger,the center current density of fish becomes smaller which reaches the minimum as the angle is 90°.In addition,high soil resistivities may intensity trend of impact current scattering into the fish pond and increase influence of fish pond distances on current densities of fish.Finally,it presents a transform scheme of installing the insulating shield and vertical grounding electrode for the horizontal grounding electrode according to actual engineering.