Effects of conductor length and angle on the accuracy of inductive interference computations

Conventional methods used to analyze the inductive interference between electric power lines and pipelines are usually based on a circuit model approach. In the computation of the line parameters in the circuit model approach, the lines are assumed to be parallel and infinite in length. When they are not parallel, a piece-wise parallelism approach is employed. Obviously, these assumptions lead to inaccuracy in the computation of inductive interference. The objective of this paper is to evaluate the level of inaccuracy introduced by the use of these assumptions. To carry out this task, a field approach and a circuit approach are used. The field approach is based on electromagnetic field theory, which does not assume the lines to be parallel and infinite in length and therefore gives accurate results. By comparing the results from the two approaches for different line lengths and different angles between conductors, the error caused by the assumptions used in the circuit model are revealed. Generally, the inductive interference computed using the circuit model approach is higher than that computed using the field theory approach. The results presented in this paper can be used as guidelines to evaluate the accuracy level corresponding to the assumptions made in the computation of inductive interference using the circuit model approach