New Technology Application and Optimization of AC Influence Mitigation for Shanxi-Beijing Gas Pipeline Ⅲ

New technologies such as lumped ground , fault shield and solid-state DC decoupler grounding were used to protections against AC influence in Shanxi-Beijing Gas Pipeline Ⅲ. The application of solid-state DC decoupler grounding and the optimization of protection point were summarized. Based on the detailed data from the on-site tests of influence degree, inspections of protection effects, analyses of operation parameters of solid-state DC decoupler and optimization of grounding point the solid-state DC decoupler technology were summarized, which may provide a reference to the design, construction, operation and inspection of protection against AC influence for underground steel pipelines.