Optimization design of impact resistance reduction of fan grounding device in mountain area

The grounding resistance of wind turbines in mountainous areas is prone to exceed the standard due to high soil resistivity and poor impact dissipation capacity. This design aims to propose an economical and effective impact resistance reduction solution by optimizing the external radiation design of the grounding device. The traditional grounding device has limited resistance reduction effect in high resistivity soil, and has not fully considered the spark discharge effect and dispersion distribution law under impulse current. This article proposes to install branch epitaxial rays on the horizontal ring, analyze the optimal number of ray elements through simulation modeling, and optimize the design to improve the scattering efficiency. This method significantly reduces the impulse grounding resistance by quantifying the utilization rate per unit length, balancing technical feasibility and economy. The simulation results show that as the number of epitaxial rays increases, the drag reduction efficiency gradually improves, but the increase gradually decreases. When the number of epitaxial rays increases from 1 to 4, the drag reduction efficiency improves significantly, while after exceeding 4, the increase significantly decreases, especially at low frequency currents, it becomes more gentle. Taking into account the difficulty and economy of construction, the optimal number of epitaxial rays for the grounding device of wind turbines in high soil resistivity mountainous areas is 4. This design reveals the current shielding law on the radiation, providing a new idea for the grounding design of wind farms in mountainous areas, which can save more than 20% of the drag reduction cost and has important engineering application value.