地铁车辆段对埋地钢质管道的干扰及轨道对地过渡电阻的测试方法

Stray Current Interference of Metro Depot on Buried Steel Pipelines and Test Method for Rail-to-Ground Transition Resistance

以国内某地铁车辆及其临近的埋地长输管道为测试研究对象,开展了出入段单向导通装置和库内轨电位限制装置不同运行工况下,地铁与管道相关电参数的现场同步测试,通过对比分析明确了其对埋地管道的杂散电流干扰影响特征;同时选取了某在役地上轨道段,利用埋地管道防腐蚀层绝缘电阻的测试方法对目标轨道的对地过渡电阻进行了试验测试。结果表明:出入段单导双向截断后,可将正线、库外和库内轨道的轨电位正向平均值降低至5 V以下;车辆段内的杂散电流水平受单导特性和库内轨道接地方式影响,单纯将出入段单导双向截断并不能完全解决车辆段的杂散电流问题;本案例中车辆段内单导和库内接地对埋地管道的杂散电流干扰影响范围小于2.6 km;利用埋地管道防腐层绝缘电阻的测试方法测试在役轨道对地过渡电阻是可行的。

Taking a domestic subway vehicle and its adjacent buried long-distance pipeline as the test research object,on-site synchronous testing of the electrical parameters related to the subway and pipeline was carried out under different operating conditions of the one-way conduction device in the entrance and exit section and the rail potential limiting device in the depot.Through comparative analysis,the characteristics of the stray current interference on the buried pipeline were clarified.At the same time,a certain in-service track section was selected and the ground transition resistance of the target track was tested using the testing method of insulation resistance of buried pipeline anti-corrosion layer.The results showed that after the bidirectional cutoff of the single conductor in the entrance and exit section,the average forward rail potential of the main line,the tracks outside the depot,and the tracks inside the depot could be reduced to less than 5 V.The level of stray current in the depot was influenced by the single conductor characteristics and the grounding method of the track in the depot.Simply cutting off the single conductor in both directions at the entrance and exit sections could not completely solve the problem of stray current in the depot.In this case,the interference range of stray current on buried pipelines caused by single conductor and grounding in the depot was less than 2.6 km.It was feasible to use the testing method of insulation resistance of buried pipeline anti-corrosion coating to test the transition resistance of in-service track to ground.