AC interference from faulty power cables on buried pipelines: A two‐step approach

Abstract

The purpose of the paper is to describe an algorithm for assessing the 50–60 Hz induced voltage and current, from a power cable in fault condition, on a nearby buried pipeline. The calculation method is a two‐step approach where both the steps are based on the solution of the transmission line model used first to characterize the inducing power cable and then the induced pipeline. The main result to be pointed out is the importance of the conductive coupling, often not considered, when modelling the phenomenon. In fact, neglecting the conductive coupling yields to underestimate the induced voltage and current along the pipeline.

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

“…It is then likely that electromagnetic interference may occur, where the source is constituted by the HVAC power line and the victim by the metallic buried pipeline [7][8][9]. In general, this electromagnetic interference consists of inductive, capacitive and conductive contributions [10] which can be studied and assessed with three different coupling mechanisms. For underground metallic pipelines, the capacitive coupling (also called electrostatic coupling) is not particularly significant as the earth provides a quite efficient screen to the electrostatic field generated by the difference of potential between the power line and the pipeline [11].…”

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

“…The interferences through which the AC power lines generate induced voltage and current on nearby pipes are inductive coupling and conductive coupling. The inductive coupling is related to the electromotive force (EMF) induced in the pipe-earth circuit, while the conductive coupling is caused by the injection of current into the soil by a transmission line during phase-to-ground fault conditions or subjected to currents [9].…”

“…Recent literature related to this issue was published by A. Popoli [13], who analyzed interference caused by the vicinity of a metallic pipeline buried in the soil to a transmission line using parameters calculated with the finite difference method (FEM). G. Lucca [9] analyzed the induced voltage and current from a transmission line in fault condition on a nearby buried pipeline with the EMF. However, these works focus on the interference of transmission lines and pipelines.…”

“…Previous research on induced voltage is mainly focused on overhead transmission lines [8][9][10][11][12][13][14][15][16]. The induced voltage on the pipeline is critical because the unbalanced current flow in the distribution system can increase the induced voltage on the pipeline.…”

“…The conclusions are presented in Section 4. An induced voltage on the pipeline line can be calculated using Carson's formula [9,23]. The relationship between voltage and current from Figure 1 is defined:…”