水电站接地装置存在的问题分析与改造措施探讨

Analysis of a Hydro-electric Station Grounding Device Problems and Rebuilding Measures

针对水电站接地装置存在的问题,笔者通过调研某水电站的地网构造情况,找出其存在的主要问题是地网连接不良、腐蚀断裂、接地电阻偏高、跨步电压和接触电压超标。根据现场土壤电阻率测试情况并结合规程,提出了分区扩建引外地网、铺设水下地网、均压等措施,对接地网进行了综合改造。计算结果表明,改造后地网的接地电阻由原来的1.199Ω下降到了0.29Ω,符合目标值0.50Ω的要求。结论认为该改造实例具有一定的典型性,对解决电力工程相关实际问题具有参考价值。

Aiming at the problems living in station grounding device,it is find that the problems were very complex which mainly contain bad connection,corrosion cracking,high grounding resistance,step voltage and contacting voltage exceeding through studying the grounding net structure of a hydropower station.According to soil resistivity testing on-site and combining with the regulation and actual condition,the measures were adopted which include expending grounding net partitioned,laying underwater grounding net,and balancing voltage for the reconstruction the grounding net.The calculation result shows that the grounding resistance dropping to 0.29 Ω from the former 1.199 Ω,after reconstruction,meeting the requirement 0.50 Ω.The conclusion is that the reconstruction example is typical,and it is of reference value to related electrical engineering problems.