Reduction in the Electromagnetic Interference Generated by AC Overhead Power Lines on Buried Metallic Pipelines with Screening Conductors

Abstract

This paper presents a numerical study on the reduction in the voltage and current induced on a 13.5 km buried metallic pipeline by an overhead power line. The mitigation effectiveness of different configurations and cross-section shapes of screening conductors is computed by means of a methodology that combines a 2D Finite Element Analysis with circuital analysis. A 35.72% reduction of the maximum induced voltage is obtained when 4 cylindrical steel screening conductors with 8 mm radius are buried 0.25m below the soil surface, along the pipeline path. The maximum induced pipeline current is reduced by 26.98%. A parametric study is also performed, to assess the influence of the per-unit-length admittance to earth of the screening conductors on the mitigation efficacy. The results show that screening conductors may help in reducing the inductive coupling between overhead power lines and buried metallic pipelines, and that the assumption of perfectly insulated screening conductors leads to an underestimation of the produced mitigation effect.

Numerical evaluation of the induced voltages in an underground pipeline using the distributed source approach

“…Due to environmental and economic reasons, mainly related to construction costs and to their impact on local ecosystems high or medium voltage power lines are forced to coexist in a relatively narrow distribution corridor with gas, petrol or water pipelines with no access to new separate rights-of-way [1][2][3]. Figure 1, shows such a situation when an underground metallic pipeline is in the close proximity with an overhead power line.…”

Analysis of Induced Voltage on Pipeline Located Close to Parallel Distribution System

“…In order to reduce the electromagnetic interference between power lines and pipelines, the most practical solution consists in worsening the electromagnetic coupling. Then, "the use of screening conductors buried in the soil above the metallic pipelines appears as a feasible solution to attenuate the voltage generated on the pipeline" by power lines [18]. Especially for designing an optimized mitigation system, a proper calculation is required to accurately predict the induced voltage on metallic pipelines.…”