Accurate Simulation of AC Interference Caused by Electrical Power Lines: A Parametric Analysis

AC interference caused by high voltage power lines on non-energized utility lines (such as pipelines, rail tracks, etc.) sharing a common corridor with the electric lines is a serious concern because it can result in electric shocks and can threaten the integrity of the utility lines. This paper compares and discusses two different methods devoted to AC interference studies. A circuit approach and an electromagnetic field approach are used to carry out a parametric analysis for various configurations of the network, grounding systems, fault current contributions and locations, and soil structures. In the circuit approach, inductive and capacitive interference components are computed first and independently from the conductive components. The overall interference is then obtained by adding all components. Two methods are used to model ground impedances with the circuit approach. The coupled-ground method accounts for the coupling between grounds and the classical method ignores the coupling by assuming that each grounding system is very far from all others. On the other hand, the electromagnetic field theory approach models the complete network and the inductive, capacitive and conductive interference effects are simultaneously taken into account. Computation results based on the various approaches and methods are then compared and discussed. Noticeable differences are found in some cases between the various approaches.