Inductive interferences between a 500 kV power line and a pipeline with a complex approximation layout and multilayered soil

This paper presents a steady-state electromagnetic interference study between a 500 kV overhead transmission line and a neighboring pipeline, based on data from a real project with a complex geometry and with emphasis on how the soil structure affects the inductive coupling mechanism, as well as the effectivity of grounding devices to reduce potentially hazardous pipeline induced voltages. Soil parameters are determined from actual field measurements, which results in a soil model composed of three layers. Conductor impedances are computed using a modification of the original Carson equation, in which the term describing the soil resistivity is replaced by an equivalent uniform of the multilayered structure, and then a circuit model is built using the Alternative Transients Program (ATP) to predict the resulting induced voltages. Results show an excellent agreement between the proposed approach and the reference values, with a comprehensible evaluation of the risks to which the interfered pipeline is exposed and how to mitigate them.