输电线路杆塔接地体地电位分布特性研究

Ground Potential Distribution Characteristics of Tower Grounding Body of Transmission Lines

为了研究雷击输电线路时输电杆塔接地装置时的暂态特性以及地电位分布情况,通过在陕西省境内选取高压输电杆塔实地测量的方式,分析了雷电流波前时间和半波时间对地电位峰值的影响、3种不同结构接地体地电位的分布规律以及同一种接地体在不同电阻率土壤环境下的电位分布情况,试验结果表明雷电流波前时间越短、土壤电阻率越高的条件下地电位峰值更大,不同结构类型接地体周围的地电位都是从地网中心注流点到地网边缘逐渐下降,地网中心附件电位梯度大于地网边缘,但3种接地体周围的局部散流规律呈现出不同的特点。研究结果为输电线路杆塔接地体优化设计和降低冲击接地电阻等方面提供参考。

In order to study the potential distribution of transmission tower grounding device when lightning strikes transmission line,the influence of lightning current front wave time and half-wave time on the peak value of ground potential,the distribution law of ground potential of three different grounding bodies and the same grounding body in different resistivity soil environment are analyzed by selecting the method of field measurement of high voltage transmission tower in Shaanxi Province. The experimental results show that the peak value of ground potential is larger when the lightning current front wave time is shorter and the soil resistivity is higher. The ground potential around the grounding body of different structure types decreases gradually from the injection point to the edge of the grounding network. The potential gradient of the central accessory of the grounding network is larger than that around the edge of the grounding network,but the local dispersion law around the three grounding bodies presents different characteristics. The research results provide reference for the optimization design of transmission line tower grounding body and the reduction of impulse grounding resistance.