Detailed study of electrical interference coupling between AC OHTL and buried metallic pipelines

Electric power lines that share the same track as metallic pipelines can induce electromagnetic field interference and induced voltage. These voltages may affect the metallic pipeline itself, cathodic protection, operational staff, and related equipment. In a system of parallel buried metallic pipelines and transmission lines using a horizontal transmission configuration, problems of interference and stray currents may cause serious damage to neighboring buried metallic pipelines. A method for calculating the longitudinal electric field (LEF), profile of induced voltages and stray currents is presented and verified using the MATLAB software m-file. In addition, LEF curves for the vertical alignment of the transmission line conductors were established. The induced voltages are influenced by a number of variables, including the geometry of the structures, type and arrangement of conductors, amplitude of the current, type of pipeline coating, and electrical resistivity of the soil. The voltage profile in the case of vertical alignment with a metallic pipeline of length L was obtained in this study.