降水与温度对接地电阻的影响分析

通过对3种接地装置接地电阻的持续观测, 分析了降水、温度对接地电阻的影响, 结果发现: 接地电阻具有明显的季节变化特征, 汛期(4—9月)降水量增加, 温度也逐渐升高, 接地电阻呈现下降趋势, 在9月之后, 随着降水的减少及温度的下降, 接地电阻逐渐升高, 此过程一直持续到翌年的2月; 接地电阻的变化率与接地体类型及尺寸大小密切相关; 降水量 < 20 mm的降水过程对接地电阻的影响较小; 当降水量偏多, 土壤含水量处于较高水平时, 多余的降水并不会使接地电阻出现明显的下降, 此时期温度对接地电阻的下降起着关键作用; 当长期干旱时, 土壤含水量偏低, 此时期较强的降水会引起接地电阻出现明显的下降, 而温度的影响相对不明显。 

ANALYSIS OF THE INFLUENCE OF PRECIPITATION AND TEMPERATURE ON GROUNDING RESISTANCE

By continuously observing the grounding resistance of three types of grounding devices and analyzing the influence of precipitation and temperature on grounding resistance, we find that grounding resistance has obvious seasonal variation. Both precipitation and temperature increase during the rainy season (April to September), and thus the ground resistance shows a downward trend. After September, as precipitation decreases and temperature drops, ground resistance gradually increases. This process continues until February of the following year. The change rate of ground resistance is closely related to the type and size of grounding device. The influence of precipitation on ground resistance is small when the precipitation is less than 20 mm. When the precipitation is too high and the soil moisture content is at a high level, excess precipitation will not cause a significant drop in grounding resistance. During this period, temperature plays a key role in the decline of grounding resistance. During a prolonged drought, the soil moisture content is low. The precipitation in this period will cause a significant drop in grounding resistance, while the effect of temperature is relatively insignificant.