Technical Presentations

Evaluation of Electromagnetic Interferences Affecting Metallic Pipelines883

Abstract
This chapter presents some analysis of the modeling techniques used to evaluate the effects of electromagnetic interference phenomena that could occur when metallic pipelines are placed close to high-... see morevoltage power lines. The electric and magnetic fields produced by overhead power lines could perturb the normal operation of the metallic pipelines through induced currents and voltages. These perturbations could be dangerous for both pipeline operating personnel (as electrical hazard) and pipeline structural integrity (due to accelerated electrochemical corrosion phenomena). The chapter depicts the electromagnetic coupling mechanisms behind the abovementioned interference phenomena and how the induced voltages could be evaluated. A parametric analysis is showcased to highlight the influence of various geometrical and electrical parameters.

Tag(s): Electromagnetic Interference, Metallic Pipelines, Electric Fields, Magnetic Fields, Induced Voltages

EMTP simulations of induced voltages and currents on aboveground pipelines by Overhead Transmission Lines878

Abstract
In this presentation the modelling of earth conduction effects on the steady-state and electromagnetic transient (EMT) analysis of aboveground pipelines caused by nearby OHLs is presented by using EMT... see moreP.

Tag(s): Induced Voltages, Induced Currents, Transmission Line, MoM-SO Modelling

Induced Voltage Study843

Abstract
MidAmerican Energy has conducted studies at some locations on our system to identify voltages that are induced due to lines on the same structures. For example, MidAmerican added a new 161 kV line fro... see morem substation D to substation E (not shown) through substation C. The line is mostly single circuit except between substations B and C where a second 161 kV line was added on the structures. There is also an existing 13.2 kV underbuilt distribution circuit on the structures between substations A to C.

The induced voltage study was performed to get an understanding on the level of voltages that may be expected when the 161 kV line from substation A to substation C is out of service, but the 161 kV line from substation D to substation C is in service and vice versa. The analysis provided very useful information on the level of induced voltages that may be expected on the 13 kV distribution feeder and helped MidAmerican to develop mitigation measures.

Tag(s): line, induced voltage, EMI

Induced Currents and Voltages in Underground Metallic Pipelines due to nearby Power Lines782

Abstract
During the last decades, environmental and economic reasons impose that gas or water pipelines share the same distribution paths with high voltage or medium voltage power lines, to restrain the financ... see moreial and the ecological costs. Therefore, the cases where underground metallic pipelines and power lines share proximal rights-of way for considerable lengths are a common practice.
The electromagnetic interference of power lines upon the metallic buried pipelines is an issue of priority, to avoid the development of induced voltages that could jeopardize the safety of the personnel and the integrity of the pipelines structure. Indeed, the developed voltages and currents can be dangerous for people who touch metallic structures connected with the pipelines or just stand nearby.

Moreover, the induced voltages can result in the corrosion of a pipeline due to electrochemical effect, leading to repair or/and replacement costs and environmental repercussions.

It is worth mentioning that the interference comprises an inductive, a conductive and a capacitive part. The capacitive part can be safely ignored in the case of buried pipelines, since the conductive component is considered only under fault conditions and affects the part of the pipeline near the faulted structure.

The inductive component is present both during faults and normal operating conditions and is the dominant one. Due to the inductive interference, voltages and currents are induced in a buried metallic pipeline.