Transmission line phase conductors and overhead wires are affected by sag that vary the distance of these conductors to the earth. This corresponds to a varying separation distance of current carrying phase conductors producing the magnetic fields to parallel pipelines in shared corridors. This paper explores the effects of phase conductors and shield wires’ sag to evaluate the induced voltages on parallel pipelines. Methodologies to consider the sag of the conductors include catenary curves, straight sloped conductors mimicking the maximum and minimum conductor elevations, and uniform conductor elevations. A sampling of typical voltage levels, spans, and transmission line phasing configurations are evaluated utilizing commercial software.

The paper provides an explanation of the impacts of sag and provides a reference for considering the inclusion of catenary curve compared to simpler approximations of the conductors for a transmission line. Identification of transmission line configurations that increase the significance of the induced voltages on parallel pipelines helps to improve public and personnel safety in shared corridors.

Subject
Circuits, Pipe surfaces, Materials, Voltage, Modeling, Materials performance, Conductors, Pipelines, Wiring, Tools, Transmission lines, Engineers, Sagging
Keywords:
AC Corrosion, Transmission Line, Electromagnetic Fields, Induced Voltages
© 2023 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2023
Association for Materials Protection and Performance (AMPP)
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