水电站接地降阻改造的措施研究

Study on the Grounding Resistance Reduction Measures of Hydropower Station

水电站接地短路电流普遍比较大,所处位置的土壤电阻率也比较高,接地降阻的难度往往比较大。结合贵州某水电站的降阻改造实例,对可供使用的降阻措施的分析,研究了适合水电站的各种降阻方法的优缺点和性价比。认为在水电站两公里以内,土壤电阻率较低的位置,使用铺设水平外引并施加性能优良的降阻防腐剂的方法和利用自然接地体的方法是性价比最高的方法;铺设水下接地网的方法也是一种很好的降阻方法,应根据实际情况依规程规定使用;做深井式接地装置的方法则应首先考虑其使用的前提条件是否满足,依情况使用。

The grounding short circuiting current of hydropower station and the location＇s soil resistivity are usually high which result in the reduction of the grounding resistance of hydropower station is difficult. By analyzing on the grounding resistance reduction measures combined with resistance reduction modification example of a hydropower station in Guizhou province, Advantages and disadvantages and cost-effective of the various kinds of resistance reduction method suitable for the hydropower station are investigated. It is concluded that the method of using horizontal expanding grounding network and good resistance reducing agent as well as utilizing the natural grounding material on the place where the soil resistivity is lower within 2 kilometers around the hydropower station are the highest cost-effective method; Setting the underwater grounding network is also a good measure which should be used according to the actual situation and the regulations. It should be considered whether the precondition is met should be considered before the method of setting deep-well type grounding device is used.