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.