Study of electromagnetic impact on buried metallic pipelines due to lightning strike on UHV AC double-circuit tower
The lightning strike on transmission lines could have electromagnetic effects on the adjacent buried metallic pipelines. The resistance coupling in pipelines is the severest, because the most high-energy lightning current is directly injected into the earth by ground conductor of fault tower when lightning strike happens. Thus for 1000 kV UHV AC double-circuit transmission lines, the paper studies the electromagnetic coupling in the adjacent buried metallic pipelines when the top of tower is subject to lightning strike and results in failure. By the establishment of simplified calculation model for the transient electromagnetic field of lightning, the effects of various factors, such as the distance between transmission lines and pipelines, crossing angle, soil resistivity, and the amplitude of lightning current, on interference voltage imposed onto pipelines and their rules are calculated and analyzed.