Structural Design of Lightning Protection and Grounding Device for Power Transmission System

When the power transmission system operates in areas with high lightning incidence, the ability of the grounding structure to withstand impulse current and the potential distribution characteristics are directly related to the safety level of the line. A composite configuration lightning protection grounding device is proposed to address the problems of single scattering path and potential concentration in traditional grounding forms under high resistivity soil conditions. Construct a three-dimensional diversion path, layered conduction structure, and circular diffusion network around the evolution process of current entering the ground, and introduce local impedance adjustment units to form a multipath collaborative diversion system. Establish an equivalent grounding resistance model, compare and analyze different structures, and conduct performance evaluation based on impulse current test and potential distribution test data. The results indicate that the peak potential of this configuration significantly decreases under the action of high amplitude lightning currents, and the attenuation of surface potential is smoother.