Influence Factors and Protective Measures of Overvoltage on Gas Pipeline When Lightning Currents Enter Ground

Lightning strikes power transmission lines or buildings, and lightning current will flow into the earth along the grounding down lead through grounding devices. If the distance between the grounding device and the gas pipeline is too close, lightning current will inevitably pose a threat to the gas pipeline. In order to study the effect of lightning strikes on nearby gas pipelines, this paper conducted experiments using a scaled model. The natural lightning strike scenario was simulated by injecting an impulse current into the ground near the pipeline. We conducted experimental tests and analysis on the distance between the lightning strike location and the pipeline, pipeline corrosion protection layer leakage points, and shielding electrode method settings on the potential of pipelines. The research findings indicate that the maximum impulse potential on a pipeline caused by lightning strikes is negatively correlated with the distance between the lightning strike location and the pipeline. The presence of leakage points in the corrosion protection layer of the pipeline near the lightning strike point will significantly reduce the maximum impulse potential of the pipeline. Installing shielding electrode next to the pipeline has a certain pressure equalization effect. After connecting the shielding electrode to the pipeline, it can effectively suppress the potential amplitude of the pipeline. By maintaining a distance from the grounding device at the lightning strike point and installing shielding electrode, the risk of overvoltage caused by lightning strikes on adjacent gas pipelines can be significantly reduced.