Mitigating Hazardous Potentials Near Pipelines Using Passive Grounding Grids

Pipelines (PLs) installed in the vicinity of power substations are subjected to produced high conductive potentials that may prove to be hazardous whenever the substation's grounding grid encounters incident fault currents. Some efforts have been made in the past to mitigate those potentials through decreasing ground resistance and/or increasing the spacing between the pipelines (PLs) and the substation grid. Such solution may prove in some cases to be impractical, inefficient, and costly. This paper proposes a novel method to reduce those conductive potentials down to safe values during those faults in the power network. A combination of a grounding passive grid (PGG) that passes under the PL together with a shielding wall would achieve this goal. The paper examines the relative effectiveness of the PGG and the wall by properly simulating them using finite-elements algorithms. The effects of the dimensions of the grid and wall on mitigating the produced potentials are investigated. An experimental model setup is used to verify the proposed concept.