某天然气长输埋地管线长沙段杂散电流干扰检测及排流实践

Stray Current Interference Detection and Drainage Practice of the Changsha Section of a Long-Distance Buried Natural Gas Pipeline

某天然气长输埋地管线长沙区域段沿途与多处高压输电线路及高铁伴行或交叉,且轨道交通A线新近投入试运行,输气管道受到交直流杂散电流混合干扰,阴极站恒电位仪无法稳定运行,部分管段交流干扰电压达18 V。针对交直流杂散电流混合干扰的问题采取了强制排流+负电位接地排流的复合排流方法进行处理,并对极性排流及固态去耦合器接地排流方法进行了分析对比,结果表明强制排流+负电位接地排流的复合排流方法对交直流混合杂散电流干扰具有优良的缓解效果。

The Changsha section of a long-distance buried natural gas pipeline had many accompanying and cross high-voltage transmission lines and high-speed railways.In addition,the metro rail transit line A was recently put into trial operation.All these above made the gas transmission pipeline subjected to mixed interference of AC and DC stray currents,the cathode station potentiostat could not operate stably,and the AC interference voltage of some pipeline sections was up to 18 V.The composite drainage method combining the forced drainage with the negative potential grounding drainage was adopted to solve the problem of mixed interference of AC and DC stray currents,and the polarity drainage and solid-state decoupler grounding drainage methods were analyzed and compared.Results showed that the composite drainage method combining the forced drainage with the negative potential grounding drainage had excellent mitigation effect on the mixed interference of AC and DC stray currents.