Effect of electromagnetic field of overhead transmission lines on the metallic gas pipe-lines

• The induced voltage along the pipeline length, due to its inductive and conductive coupling with OHTL, is calculated.
• The effect of both fault and unfaulted conditions of OHTL is studied.
• The calculated induced voltage along the pipeline length is compared with the measured values.

This paper presents a study of the overhead transmission lines (OHTLs) electromagnetic fields effects on the metallic gas pipelines. The inductive and conductive voltages between the overhead transmission line and metallic gas pipelines, in normal operation and under phase to ground fault condition of the overhead transmission lines, are calculated. ATP software is used to simulate the OHTL under faulty condition. MATLAB program is used to calculate the induced voltages taking into account the effects of various parameters, such as: separation distance between the OHTL and the metallic gas pipelines, case of transmission line (phase to ground fault condition or normal operating condition), the screening factor and the soil resistivity on the magnitude of the induced voltage along the length of the metallic gas pipeline. The method used to calculate the induced voltage by inductive is based on the well known method “distributed source analysis”. Case study, to measure the induced voltage on the metallic gas pipelines from OHTL under normal operating condition, is presented. The comparison between the measured and calculated results shows a good agreement between them.