Modeling and Application of Complex Soil Structure Influenced by Grounding Device of Tower

摘要

In transmission lines tower earthing device assessment and reconstruction, the existing tower earthing device will lead to inversion error of soil electric parameters. As a result, the inversion data can’t represent the real electric parameters of soil. In order to obtain the accurate soil structure around the tower earthing device, this paper proposes an inversion strategy combining finite element method (FEM) with differential evolution (DE) algorithm. Firstly, FEM is used to calculate the theoretical value of soil apparent resistivity without earthing device, and the effectiveness of FEM is verified by complex image method (CIM). Then, DE algorithm is used to optimize the parameters of soil with earthing device and the optimal values of soil parameters are obtained, the validity of the inversion method is verified by comparing it with the set model. The method has been applied to the reconstruction of earthing device of tower in Foshan city, Guangdong province. The test results show that the reconstruction plan guided by the soil structure obtained by the inversion method can effectively reduce the impulse grounding resistance of the tower in power transmission networks.