为研究雷击高压输电线路对临近埋地油气管道的电磁影响,利用SES CDEGS数值模拟软件建立了国内某现场案例的输电线路和临近埋地油气管道电磁干扰模型,计算预测了雷电流对管道造成的干扰情况。基于国内外相关标准和研究成果的调研,从人身安全、管道防腐蚀层击穿风险和管壁电弧熔伤风险三方面建立了雷电流对管道电磁影响的风险评价指标,对现场案例的干扰风险进行了评价,同时计算分析了土壤电阻率和杆塔接地网类型对管道过电压和接地网导体泄漏电流的影响。结果表明:现场案例中雷电流导致的管道安全风险低;土壤电阻率对管道过电压和接地网导体泄漏电流有明显影响,其随土壤电阻率升高而增大;采用水平接地网时,在接地网表面积相同的前提下,接地网结构对管道过电压和接地网导体泄漏电流的影响较小;垂直接地体的引入可缓解管道过电压,但其数量不宜过多。

In order to study the electromagnetic interference of lightning strikes on high-voltage AC transmission lines on adjacent buried oil and gas pipelines, an electromagnetic interference model of transmission lines and adjacent buried oil and gas pipelines in a domestic field case was established by using SES CDEGS numerical simulation software, and the interference caused by lightning current on pipelines was calculated and predicted based on the established model. The risk assessment indexes for the electromagnetic effect of lightning current on pipelines were established from three aspects, including personal safety, pipeline coating breakdown risk and pipe wall arc melting risk, based on the investigation of relevant standards and research results at home and abroad. The risk level of field case was evaluated using the obvious risk assessment index, and the effects of soil resistivity and tower grounding grid structure on the pipeline overvoltage and the leakage current from grounding conductor were calculated and analyzed. The results showed that the pipeline safety risk caused by lightning current was low in the field case, and the soil resistivity had a significant effect on the pipeline overvoltage and the leakage current from the grounding grid conductor, which increased with the rise of soil resistivity. When using a horizontal grounding grid, the structure of the grounding grid had little effect on the pipeline overvoltage and the leakage current from grounding grid conductor under the precondition of the same surface area of grounding grid. Vertical grounding electrode could relieve pipeline overvoltage, but the number should not be too much.