SHIELDING OF PIPELINES IN CLOSE PROXIMITY TO SUBSTATION GROUNDING GRIDS

Abstract

The protection of pipelines adjacent to power substations against electric disturbance -during power system abnormal operation or lightning- is of paramount importance. One proposed method of implementing effective shielding is by the construction of a shielding wall between the substation’s grounding grid and the external installation to be protected. This thesis deals with this problem and offers a methodology, by which the optimal wall dimensions and location are sought. In doing so, the economics of the shielding wall construction is considered as well. A method that enhances the mitigation of potentials, proposes building a passive grounding grid (PGG) beneath the pipeline. A combination of a grounding passive grid (PGG) that passes under the pipeline together with a shielding wall would achieve this goal. The thesis examines the relative effectiveness of the PGG and the wall by properly simulating them using finite-elements algorithms. An experimental model setup is used to verify the proposed concept.