为了解高速铁路产生的杂散电流是否含有直流成分,近期在成都-都江堰高速铁路某段进行了杂散电流测试,通过测量机车通过时走行轨附近的地表直流电位梯度,来判断直流杂散电流的强度及其变化规律。测试结果表明当该高速铁路供电段有机车通过时,轨道附近存在非常明显的直流杂散电流,距轨道10 m处最大地电位梯度可达120 mV/m,30 m处最低为2 mV/m,地电位梯度在垂直轨道的方向上变化较大,测试点的最大地电位梯度并不出现在机车通过该测试点时,而是存在一个延迟时间。根据测试结果,建议高速铁路的轨道要注意防止直流杂散电流的腐蚀,并且高速铁路附近的埋地金属管网,有必要采取防止直流杂散电流腐蚀的措施。同时测试结果也提出了一个问题：为什么高速铁路运行时会产生大量直流性质的杂散电流？该测试结果将为接下来的研究提供依据。%In order to know whether there is DC current in the stray current produced along the high-speed railway or not, a testing was carried out at a section of Chengdu-Dujiangyan high speed railway recently. DC stray current intensity and variation is adjudged by measuring the surface DC potential gradient near the running rail when the locomotive is passing through. The results show that there is obvious DC stray current near the track when the locomotive is passing through the power supply section of high-speed railway, where the maximum potential gradient is 120 mV/m at the test point 10 m far away from the track and the minimum value is 2 mV/m at the test point 30 meters away from the track. The change of ground potential gradient in the direction perpendicular to the track is bigger than that in the direction par-allel to the track. The max value of potential gradient does not appear when the locomotive is passing through the testing point, but there is a time delay. According to testing results, it is suggested that the track of high speed railway and the buried metal pipe network near it should be protected from corrosion of DC stray current. The testing result also raises a question:why a large amount of DC stray current exists along the High speed railway when the train is running? The re-sult will provide a basis for future researches.
展开▼
