In this paper the induced voltages along the length of the buried gas pipeline, due to the inductive couplingand conductive coupling between this pipeline and the overhead transmission line (OHTL), are calculatedunder normal and fault conditions of the OHTL. Also, this paper deals with the mitigation of these inducedvoltages.Fault conditions of the OHTL include symmetric and un-symmetric faults. Where, ATP software is usedto simulate the OHTL under all fault conditions. The obtained results from the ATP program are used tocalculate the pipeline induced voltages under both normal and fault conditions.Mitigation system to minimize the impact of the OHTL on pipelines at normal and fault conditionsis designed. Under normal condition, the pipeline induced voltages, after earthing system (mitigationsystem) was erected, are measured and compared with the calculated values.Also, pipeline coating discharging current and pipeline AC current density due to inductive couplingunder normal operation and due to inductive and conductive coupling under single phase to ground faultcondition of the OHTL, before and after erecting the mitigation system, are calculated and analyzed. |
