Simulation Analysis of Electromagnetic Interference Effects of AC Traction Metro Tunnels on Oil and Gas Pipelines

［Objective］ Currently, several cities in China are planning 25 kV AC (alternating current) power supply metro lines, inevitably there will be paralled sections of oillgas pipelines run parallel to metro tunnels. During metro operation, AC interference can lead to electrolytic corrosion of oil and gas pipelines, potentially causing safety incidents. To ensure the safe operation of both metro systems and pipelines, it is necessary to study the coupling effects between AC-powered metro tunnels and oil and gas pipelines. ［Method］ The CDEGS grounding simulation software is used to model metro tunnels and analyzed the impact of different tunnel construction methods on AC interference in oil/gas pipelines. ［Result & Conclusion］ Simulation results indicate the following: tunnels constructed using the mining method exhibit superior suppression of AC interference in oil and gas pipelines compared to those constructed using the shield tunneling method; the induced voltage difference at both ends of the pipelines primarily depends on their coupling relationship with the catenary network location; and the withstand voltage of pipeline coatings is influenced by both the surface potential and the induced voltage on the pipeline.