接地电阻测量与三维地网技术的探讨

Discussion on Measurement of Grounding Resistance and Three-Dimensional Grounding Grid Technology

随着电力系统电压等级的不断提高和系统容量的不断增大,对接地网的接地电阻值提出了更高的要求,而变电站良好的接地是电力系统安全运行的根本保证。为使高土壤电阻率、扩张裕度有限地区的变电站地网满足设计规范,增设垂直接地体,采用三维地网新技术,可有效降低接地网接地电阻、接触电压和跨步电压。通过分析接地电阻测量的基本原理,探讨了理想接地球体状况下的三极直线法(0.618法)和三极三角形法(30°夹角法),对类似接地工程的设计、施工及测量等,具有一定的参考价值和借鉴作用。

With the increase of electric power system voltage level and the continuous improvement of the capacity of the system, the grounding resistance value is putting forward to higher requirements. And also the good substation grounding system is the fundamental guarantee for the safe operation of electric power system. In order to make sure that the grounding grid＇ s design can grantee safety of equipment and people at the areas of high resistivity soil and limit expansion region of grounding grid horizontal expansion, the vertical grounding electrodes is added. The new technology of three-dimensional network is adopted, which can effectively reduce grounding resistance of ground grid, touch and step voltage. The basic principle of grounding resistance measurement is analyzed. The three-electrode straight line method （ method 0. 618 ） and three-electrode triangle method （30 °angle method） of ideal grounding ball condition are discussed. These methods provide certain reference value for similar project.