山区输电线路杆塔立体均压环接地体冲击特性分析

Impulse Characteristics of the Grounding Body for Stereo Pressure Balance Ring of Transmission Lines in Mountain Areas

山区输电线路杆塔所处位置通常土壤电阻率高且空间有限,故散流效果差,降阻比较困难。针对这些问题,本研究使用CDEGS软件设计了立体均压环结构接地体,在不同激励电流类型、土壤电阻率、接地体深度和水平射线长度情况下,进行了冲击特性的分析。仿真结果表明:在工频电流和雷电流作用下,该接地体都能够具有良好的均压和散流效果。相同土壤电阻率下,立体均压环接地体冲击接地电阻比传统圆环形接地体冲击接地电阻至少可较低8.9%,最大跨步电压至少可降低16.0%,在高土壤电阻率下,降低幅度增大。接地体埋设深度和水平射线长度都存在有效数值,该接地体最优埋深在1 m~1.5 m,水平射线长度在4 m左右。

The location of transmission line towers in mountain areas usually has high soil resistivity and limited space,so the effect of dispersing current is poor and resistance reduction is difficult.In response to these problems,the author uses CDEGS software to design a three-dimensional pressure equalizing ring structure grounding body.Under the conditions of different excitation current types,soil resistivity,grounding body depth and horizontal ray length,the impact characteristics are analyzed.The simulation results show that under the action of power frequency current and lightning current,the grounding body can have good voltage equalization and current dissipation effects.Under the same soil resistivity,the impulse ground resistance of the three-dimensional equalizing ring grounding body can be at least 8.9%lower than that of the traditional circular grounding body,and the maximum step voltage can be reduced by at least 16.0%.Under high soil resistivity,the amplitude increases.Both the buried depth of the grounding body and the length of the horizontal ray have valid values.The optimal buried depth of the grounding body is 1 m~1.5 m,and the length of the horizontal ray is about 4 m.