基于土壤离子化的雷击输电线对管道干扰风险评估

广东电网有限责任公司

输电线路;埋地管道;雷击;土壤离子化;风险评估

Risk assessment of electromagnetic interference to buried pipelines from lightning strikes on transmission lines based on soil ionization
ZHU Wenwei,XU Chenghao,WANG Xinghua,LIANG Aiwu

Guangdong Power Grid Corporation

transmission line, buried pipeline, lightning strike, soil ionization, risk assessment

DOI: 10.6047/j.issn.1000-8241.2025.01.006

备注

【目的】随着中国能源跨区域调配事业的蓬勃发展,输电线路与油气管道建设进入了飞速发展的新阶段,两者共用同一能源“公共走廊”的现象较为常见,导致“管-线”间的交流干扰问题日益突出。特别是当输电线路遭受雷击灾害时,高额雷电流注入土壤,导致处于受击杆塔接地装置附近的埋地管道受到很强的雷击过电压,可能造成管道绝缘涂层烧蚀、击穿,引发火灾、爆炸等事故,威胁生产安全。【方法】为对靠近输电线的管道进行有效安全评估,通过对不同阻值的土壤样本进行雷电流浪涌冲击,得到不同电压冲击下的土壤电阻率,进一步分析土壤发生离子化时其阻值的变化情况,根据所得结果构建包含土壤离子化区域的电磁干扰模型。【结果】结合电磁干扰分析软件进行管道涂层干扰电压计算,发现土壤发生离子化后,涂层受到的干扰电压远大于未考虑土壤离子化时的结果,雷击灾害引起的土壤离子化是影响管道涂层干扰电压大小的重要因素,在进行干扰分析的过程中不容忽视。【结论】基于考虑土壤离子化的电磁干扰模型展开计算,以3PE涂层的耐压限值为109kV作为安全限值,得到了不同土壤初始阻值下的“管-线”安全距离,并结合接触管道人员的人身安全以及管壁金属烧蚀损伤的风险评估,进一步验证了离子化安全距离的可靠性。(图9表8,参[26]
[Objective] With the vigorous development of cross-regional energy allocation in China, the construction of power transmission lines and oil & gas pipelines has entered a new stage of rapid growth. Consequently, more “shared corridors” for these two transmission systems have emerged, leading to increasingly prominent AC interference between the pipelines and power lines. Particularly during lightning strikes on transmission lines, the high lightning current injects into the soil, causing significant lightning overvoltage on buried pipelines located near the grounding devices of the affected towers. Such overvoltage may ablate or break down pipeline insulation coatings, resulting in fires, explosions, and other accidents, thereby threatening production safety. [Methods] This paper aims to develop a solution for effectively assessing the safety of pipelines located adjacent to transmission lines. Lightning current surges were applied to soil samples with varying resistance values to determine soil resistivity under different voltage surges. The subsequent analysis examined variations in soil resistance values due to ionization. The results obtained were used to construct an electromagnetic interference model that incorporates a soil ionization area. [Results] By integrating calculations regarding the interference voltage on pipeline coatings, conducted using electromagnetic interference analysis software, the comparison revealed that the interference voltage imposed on the coatings after soil ionization was significantly greater than the results without considering the impacts of soil ionization. The soil ionization caused by lightning strikes emerged as a crucial factor influencing the magnitude of the interference voltage on pipeline coatings, which must not be overlooked in interference analysis. [Conclusion] The developed electromagnetic interference model, which incorporates the effects of soil ionization,supports the calculation of safe distances between the pipelines and power lines for various initial soil resistance values, using a withstand voltage limit of 109 kV for 3-layer PE coatings as the safety threshold. Additionally, the assessment of the safety of operators contacting the pipelines, along with the risk of metal ablation damage to the pipe wall, further verified the reliability of the safe distances calculated using this model. (9 Figures, 8 Tables, 26 References)
·