±1100 kV特高压直流接地极对埋地油气管道直流干扰实测与分析

Measurement and Analysis of DC Interference of ±1 100 kV UHVDC Grounding Electrode to Buried Oil and Gas Pipeline

直流接地极电流会对大范围的埋地油气管道造成腐蚀和危险影响,特别是±1 100 k V特高压直流接地极,额定入地电流大,影响程度更大,影响范围更广。为获得特高压直流接地极对埋地油气管道的影响水平和管道电压分布规律,文中首次在昌吉—古泉±1 100 kV特高压直流输电工程调试期间,对邻近的川气东送管道进行了全面的测试,得到了管道通/断电电位分布、泄漏电流密度、阀室引压管电压和土壤电位梯度。根据现有标准中管道直流干扰的各项评价指标对管道测试结果进行了分析,相关测试结果可为川气东送管道的安全运行维护提供数据支撑,也可为后续直流接地极选址和埋地油气管道路径选择提供参考。

Current of DC grounding electrode will cause corrosion and dangerous effects on a large range of buried oil and gas pipelines,especially the grounding electrode of ± 1 100 kV UHVDC transmission project has large rated grounding current,greater degree of influence and wider range of influence. In order to obtain the influence level and the distribution of pipeline voltage of UHVDC grounding electrode on buried oil and gas pipeline,the comprehensive test of the nearby gas transmission pipe line of Sichuan-East is performed for the first time during the the commissioning of Changji-Guquan ± 1 100 k V UHVDC transmission project. The on/off potential distribution of the pipeline,leakage current density,voltage of the impulse pipe in valve chamber and soil potential gradient are obtained. According to the evaluation indexes of pipeline DC interference in existing standards,the test results of the pipeline are analyzed. The relevant test results can provide data support for the safe operation and maintenance of pipeline of Sichuan-East,and can also provide reference for the selection of grounding electrode location in subsequent DC projects and buried oil and gas pipeline path.