A novel design of a composite grounding system for transmission grids in high-resistivity areas of new power systems

For new power systems, stable operation depends on a safe and reliable grounding system, especially in complex terrains such as mountainous areas with high soil resistivity. Traditional grounding designs often face challenges like excessive grounding resistance, insufficient lightning protection performance, and high economic costs, which severely threaten the safety of transmission grids. To address these issues, this study proposes a novel composite grounding system based on conductive concrete materials. The core objective is to optimize the design parameters of the composite grounding electrode for electrical performance and economic efficiency, thereby providing a feasible technical solution for grounding system construction in high-resistivity mountainous areas.

First, a numerical model of the composite grounding system suitable for high-resistivity areas was constructed to clarify the quantitative mapping relationships between structural dimensions, laying methods, material parameters, and key indicators such as grounding resistance and project cost. Second, taking electrical performance indicators and economic cost as optimization objectives, a multi-objective optimization model was established, with grounding electrode length, spacing, burial depth, and conductive concrete mix ratio as optimization variables. To solve this model, an improved particle swarm optimization algorithm was designed to enhance the global search ability and convergence speed by introducing adaptive inertia weights and mutation operators. Finally, a 110 kV transmission line project in the mountainous areas of Zhejiang Province was selected as a case study for simulation analysis and on-site comparative verification.

Simulation results show that the optimized design effectively reduces the grounding resistance to comply with relevant electrical standards. Compared with traditional grounding schemes, the proposed composite grounding system lowers construction costs while maintaining excellent electrical performance. Furthermore, the conductive concrete material exhibits good corrosion resistance and stability, with a predicted service life exceeding 30 years.

This study develops an optimized design method for composite grounding systems based on conductive concrete, effectively balancing electrical performance and economic efficiency. The proposed method addresses the challenges of excessive grounding resistance and high costs in high-resistivity mountainous regions, providing both a theoretical foundation and an engineering reference for grounding system design in new power systems. Future research will focus on integrating intelligent monitoring technologies to enable real-time performance detection and early warning, further enhancing the reliability and intelligence of grounding systems.