天湖水电站接地问题探讨

Inquiring into the Problem of Grounding of the Tianhu Hydropower Station

天湖水电站处在花岗岩地区,土壤电阻率高,接地装置按高土壤电阻率地区处理。综合采取引外接地、水中接地、施用降阻剂等措施,以降低接地电阻;采取3m×3m均压网、块石、沥青混凝土地面填层等,以降低配电装置范围内的接触电压与跨步电压,保证运行安全。唯压力钢管将高电位外引问题尚待研讨。

The Tianhu hydropower station is situated in granite stratum area, where the soil is of high resistivity. So the grounding device must be processed by such high soil resistivity. We take some measures, such as: leading out grounding, underwater grounding and using reslstance—fall agent, to lowering grounding resistance. In order to lower contact voltage and cross voltage around switch device, to insure operation safety, we also take some measures, such as using voltage balance net with sizes 3m×3m, block stone, asphalt concrete grouting layer on ground, etc. But the subject of high potential led out by penstock meeds more discussion.