Different approaches in calculating AC inductive interference from power lines on pipelines

Abstract

When dealing with 50–60 Hz inductive electromagnetic interference from power lines on pipelines, the key parameter is represented by the per unit length mutual impedance between the power line conductor-Earth and pipe-Earth circuits. Different philosophies can be followed concerning the evaluation of this parameter, i.e.: modelling the power line conductors by wires of finite length or by wires of infinite length. What is missing in the literature is a comparison of the interference results (i.e. overvoltage and overcurrent induced on the pipeline) that are obtained by following these different approaches. Thus, this study is devoted to investigate this neglected point relevant to the 50–60 Hz interference issue. To this aim, the authors also present and compare some results of interference calculated in real cases and, on the basis of them, they draw some conclusions concerning which, in their opinion, is the best approach.