Electromagnetic Effects on Underground Oil/Gas Pipeline of the Lightning Strike on EHV AC Transmission Line

Taking a 750kV EHV double circuit line on the same tower for example,we studied the electromagnetic influence of the lightning strike on underground oil/gas pipeline on transmission line.By modeling of EMTP,we can obtain the distribution characteristics of current along ground wire and tower and the effect of ground impedance and lightning location after lightning strikes on tower.Based on the computational model for the method of moment,the distribution characteristics of the metal potential,coating potential,and coating stress voltage on the oil/gas pipeline parallel to or across the transmission line are investigated,and the approximate expression for the cross is obtained,which involves the lightning current,pipeline type,soil resistivity,and the distance between the pipeline and tower grounding structure.With the lightning electrical strengths of different coatings,we can achieve the safety distance between the pipeline and tower grounding structure for different lightning current peaks,providing important reference data for power engineering and oil/gas pipeline construction.