接触网覆冰下高速弓网系统电弧电接触行为特征与损伤机制

The pantograph-catenary system is the unique way to get energy for high-speed trains. With the increment of speed of high-speed trains, the pantograph-catenary system suffers more wear. Especially when the catenary icing, the pantograph arc generates frequently and the pantograph slide wears abnormally, which results in the reduction of pantograph slide life and the increase of pantograph-catenary system operational risk. For this problem, this project aims to ensure the pantograph-catenary system safe operation, and proposes that the studies of pantograph-catenary system arc contact characteristics and damage mechanism under catenary icing, focused on two major damage factors including electrical erosion and mechanical wear. Firstly, the effects of ice on pantograph arc and electrical erosion are explored. Secondly, the physical/chemical reactions between the ice and pantograph-catenary system are studied, for revealing the mechanism of the pantograph-catenary system current carrying friction and wear characteristics with the catenary icing, meanwhile to build the corresponding model. At last, considering electrical and mechanical damage characteristics and current-flow characteristics of pantograph-catenary system, the best operation parameters of pantograph-catenary system under the catenary icing are confirmed. The development of the above work lays an important foundation for ensuring the safe and stable operation of the high-speed pantograph-catenary system in snow weather.

弓网系统是高速列车获取能量的唯一途径。随着高速列车运行速度增加，弓网系统磨耗加剧，尤其在接触网覆冰情况下，弓网电弧频发，受电弓滑板异常磨耗增加，大大缩减了滑板寿命，加大了弓网系统运行风险。针对该问题，本项目拟以保障弓网系统安全运行为目标，抓住弓网系统中电气侵蚀与机械磨损两大损伤因素，开展接触网覆冰条件下弓网系统电弧电接触行为特征与损伤机制的研究。首先研究接触网覆冰对弓网电弧及其侵蚀机制的影响；其次探明载流摩擦过程中覆冰与弓网材料的物理/化学作用，揭示覆冰对弓网载流摩擦磨损机理的影响，建立接触网覆冰条件下弓网载流摩擦磨损模型；最后综合考虑弓网系统电气与机械损伤特性，在保证受流质量基础上确定其在接触网覆冰下最佳运行参数。以上研究为保障高速列车在冰雪天气环境中安全稳定运行奠定了理论基础。

弓网系统是高速列车获取能量的唯一途径。随着高速列车运行速度增加，弓网系统磨耗加剧，尤其在接触网覆冰情况下，弓网电弧频发，受电弓滑板异常磨耗增加，大大缩减了滑板寿命，加大了弓网系统运行风险。针对该问题，本项目以保障弓网系统安全运行为目标，抓住弓网系统中电气侵蚀与机械磨损两大损伤因素，开展接触网覆冰条件下弓网系统电弧电接触行为特征与损伤机制的研究。.首先开展了不同电极极性、材料组分下的电弧发展演化特性试验与电弧侵蚀实验，发现了电弧作用下碳材料局部快速蒸发、预埋气体溢出导致的高速蒸气流及等离子体气旋现象，阐明了高速蒸气流导致的电弧阻抗变化是弧压跳变的主要原因。探明了热量、材料热物理属性对碳、铜、碳-铜复合材料电极电子发射的影响机制。解析了浸铜碳电极持续电子发射能力的增强、电弧温度的升高是其分断能力增长的主要原因。.其次建立了“接触网-残余冰-液态水-滑板”的电接触模型，通过对比含水与干燥滑块载流时的摩擦磨损性能实验，发现大电流下碳材料含水程度较低时剥落磨损明显，而含水程度较高时电气磨损剧烈并且磨损程度大于剥落磨损；小电流时在滑块饱和湿润之前其润滑作用起主导作用，摩擦面上的凸峰受到水膜润滑和保护的数量和比例增加。.最后，基于abaqus有限元软件完成了覆冰接触网的有限元建模，得到了接触网在自重和覆冰载荷共同作用下的平衡状态，发现了在覆冰条件下弓网受流质量急剧变差，揭示了覆冰下接触网参数对弓网接触力和摩擦磨损的影响规律，为今后接触网覆冰条件下高速弓网运行参数的优化匹配设计提供了参考价值。