Total AC Interferences Between a Power Line Subject to a Single-Phase Fault and a Nearby Pipeline With Multilayered Soil

This article describes the problem of electromagnetic interferences between power lines and metallic structures, caused by inductive and conductive coupling mechanisms, and the main risks to which personnel and facilities are exposed. An EMTP-based implementation is proposed to predict induced voltage levels on a target circuit, due to interferences caused by overhead power lines under steady-state nominal load, as well as fault conditions, using generalized formulas to represent the
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-layered soil. Results are tested by means of a case study of a real shared right-of-way project and comparisons with results obtained using industry-standard software. Results show that the proposed method is accurate, with errors smaller than 8%. Stress voltage values in the interfered pipeline are the order of 50 kV, exposing the structure coating to risk of breakdown, which may lead to corrosion and pipeline failure. A mitigation is designed and proven to reduce voltage values to safe levels, in compliance with the nominal limits from the manufacturer.