Study on the grounding material and soil contact resistance determination
CHEN Sifu1, TAO Xiaoli2, ZHU Yuanbo1, HU Songjiang1, ZHANG Guofeng1
1. He'nan STAR Power Equipment Co., Ltd, Xuchang, He'nan 461500; 2. Lhasa Power Supply Company of State Grid Tibet Electric Power Co., Ltd, Lhasa 850010
Abstract:Correctly estimating the contact resistance between the grounding conductor and the soil of the grounding grid can effectively reduce the occurrence of “overprotection” and “underprotection” in the design of grounding materials of the grounding grid, and is of great significance for the reasonable selection of the type, conductor specification and material type of the grounding grid. Starting from the linear relationship between the contact resistance and the contact area between the grounding material and the soil, the previous methods are improved by using the hemispherical grounding electrode and return electrode arranged concentrically, including the linear relationship between grounding body resistance, grounding body-soil contact resistance and soil resistance, and the measurement method of contact resistance between grounding material and soil is studied. A hemispherical test model with concentric arrangement is established. The contact resistances of hard and soft grounding materials in different soil environments are effectively measured, and the test analysis is carried out for hot-dip galvanized steel and graphite-based flexible grounding materials. The results show that with the increase of soil particle size, the contact resistance between the grounding body and the soil increases, and the contact resistances of graphite-based flexible grounding body with soil in various soil environments are lower than that of hot-dip galvanized steel grounding body.
陈四甫, 陶晓莉, 朱渊博, 胡松江, 张国锋. 接地材料与土壤接触电阻测定方法研究[J]. 电气技术, 2023, 24(3): 31-35.
CHEN Sifu, TAO Xiaoli, ZHU Yuanbo, HU Songjiang, ZHANG Guofeng. Study on the grounding material and soil contact resistance determination. Electrical Engineering, 2023, 24(3): 31-35.