500kV输电线路杆塔接地电阻季节变化特性测量与分析

Investigation on seasonal variation characteristics for grounding resistance of 500kV transmission tower

输电线路杆塔接地电阻测量是线路防雷的一项重要工作内容,而杆塔接地电阻随降雨量的季节性变化而变化。采用三极法在不同月份对杆塔接地电阻进行测量,分析降雨量、温度、地形、土壤类型等因素对杆塔接地电阻的影响,探讨不同因素对季节系数的影响机制。测量与分析结果表明:500kV输电线路杆塔接地电阻出现季节性变化最主要影响因素是不同季节降雨量的变化,并由所测数据分析地形对接地电阻季节性变化的影响,给出该地区平地和坡地的接地电阻季节影响系数。

The measurement of tower grounding resistance is the important work for lightning pro- tection, and the tower grounding resistance changes over seasonal variation in rainfall. Three-pole method was used to measure the grounding resistance of the transmission tower during different monthes. Factors on tower grounding resistance, such as rainfall, temperature, terrain, soil type were investigated and the influence mechanism of different factors on the seasonal coefficient were discussed. The research results showed that seasonal variation for the grounding resistance of 500 kV transmission tower is mainly due to rainfall variation. And terrain influence of the seasonal variation is analyzed via the testing data, and the season effect coefficient in this area about the grounding resisitance of flat and sloping is also presented.