特高压直流接地极对西二线管道的干扰研究

Interference of UHV DC Grounding Electrode with Second Pipeline of West-east Gas Pipeline

分析了酒泉-湖南±800 kV特高压直流接地极对西气东输二线管道的影响,选取了受干扰程度较为严重的管段进行了管道电位、电流密度以及腐蚀速率的检测。结果表明,接地极运行时,约157 km管道处于欠保护状态,108 km管道处于过保护状态;管道受到接地极的干扰时,两个监测点的电流密度分别达到-37.93和-78.60 A/m^2,部分管段腐蚀速率分别达到0.496和0.54 mm/a,远高于标准允许值0.01 mm/a。

Ultra-high-voltage DC(UHV DC) grounding poles can cause interference with buried metal pipelines during discharge. The interference can cause potential abnormalities so that to make the pipelines in danger. The influence of the ±800 k V UHV DC grounding pole of Jiuquan-Hunan UHV transmission line on the pipelines of the second line of the West-East Gas Pipeline was analyzed, especially for a selected pipeline section, which suffered from severe disturbances in terms of the pipeline potential,current density and corrosion rate. It reveals that during discharging of the grounding electrode, about 157 km of the selected pipeline is under-protected, while the other 108 km of the pipeline is over-protected. When the pipeline is disturbed by the grounding electrode, the current densities of the two desired monitoring points reach-37.93 and -78.60 A/m^2 respectively, correspondingly, the corrosion rate of the pipe sections reached 0.496 and 0.54 mm/a, far higher than the standard allowable value of 0.01 mm/a.