Impulse characteristics of grounding devices of transmission tower based on a simulation experiment in a two-layer soil

摘要

Reducing the impulse grounding resistance of grounding devices of a transmission tower is a major measure to improve the lightning impulse, withstand the level, and to ensure power system stability. As the tower mainly adopts a box with radiation grounding devices, this paper uses a simulation experiment method based on similarity theory and researches the influence of radiation length, radiation angle and the proportion of the box and radiation, and the branch length on the box with radiation grounding devices' impulse characteristics in the layer soil model. Results of the experiments show that the branches have an effective use of length; the box and radiation have an optimal proportion improper length radiation or proportion will render the resistance reduction ineffective. According to the results of the experiments, we have got optimal-length rays and put forward an impulse characteristic featuring a better tower grounding structure which is named T2-15-25 & H2-15.