环境因素对地铁钢轨扣件绝缘性能影响的试验研究

城市轨道交通钢轨对地绝缘性能的好坏是影响杂散电流大小的主要原因。而对地绝缘性能的好坏主要由钢轨扣件的绝缘性能决定。扣件的绝缘工作环境相当复杂,污秽、温度及湿度都会引起绝缘性能的下降,造成过渡电阻的减小。通过搭建扣件绝缘性能测试平台,研究了不同环境因素对扣件绝缘性能的影响,研究发现:湿度对绝缘性能的影响十分严重,主要表现在其增大钢轨表面电导率,形成泄漏电流的低阻流通路径;温度的影响主要体现在其对水蒸气凝结起抑制作用,温度越高钢轨表面越不容易凝露;雾气中的盐分也会增加扣件绝缘性能的下降。

Experimental Study of Environmental Influence on Metro Rail Fastener Insulation Performance

The insulation performance of urban rail transit rail to ground is the main reason that influences the stray current,while the insulation performance is mainly determined by the insulation fasteners.The working environment of insulation fastener is quite complex,fouling,temperature and humidity will cause the degradation of insulation performance and the decrease of transition resistance.In this paper,the impact of different environmental factors on the fastener insulation performance is studied by constructing a fastener insulation test platform.The result shows that the influence of humidity on insulation performance is very serious following the increase of the rail surface conductivity,resulting in the low resistance flow path for leakage current.The temperature impact is mainly reflected in its inhibition of water vapor condensation,the higher the temperature is,the less exposed the rail surface will be.In addition,the salt content increase in the fog will reduce the fastener insulation performance.