基于高速滑动振动的弓网电弧侵蚀特性与调控方法研究

The relationship between pantograph and catenary is one of three basic relationships for the safety of high-speed railway. Pantograph-catenary arc is the key influence factor for current collection from sliding contact. With the increasing of train’s speed, vibration between pantograph and catenary enlarged, arc occur frequently, arc erosion is becoming the primary influence factor for the server properties of pantograph-catenary system. Relative research work urgently to be carried out. For some particularity of pantograph-catenary system, such as high speed sliding contact, pantograph-catenary material is asymmetric, multi-layer interface on the surface of pantograph-catenary electrode rising from current-carrying friction, the arc erosion characteristics is different from switch arc. In the project, the motion mechanism for arc root and arc column under high speed sliding has been studied. Electrode materials and microstructure’s impact on arc root distribution has been analyzed, material transfer has also been studied. The influence mechanism on energy density distribution and electrode heating process rising from arc root motion, root column stretch and multi-layer microstructure has been revealed. A pantograph-catenary arc erosion model has been established. The influence such as material transfer, corrosion, and splash arising from arc energy and arc root aggregation state has been studied. Method to decrease arc erosion has been proposed basing on optimizing pantograph-catenary electrode silhouette and improving its microstructure.

弓网（受电弓/接触网）关系是高速铁路安全运行的三大基础关系之一，弓网电弧是影响高速铁路弓网滑动受流的关键问题。随着高速铁路运营速度提升，弓网系统滑动振动加剧，弓网电弧频繁发生，电弧侵蚀已成为影响弓网系统服役性能的首要因素。由于弓网高速滑动、强气流、电极材料不对称及表面多层界面结构，导致弓网电弧弧根弧柱形态、运动轨迹变化，影响了极间材料转移、能流密度分布和阴阳极热过程，使得弓网电弧与开关电弧存在显著差异，弓网电弧侵蚀特性研究面临全新的挑战。本项目主要研究弓网高速滑动振动时弧根弧柱的运动机制，强气流场下的能量逸散过程，解析电极材料及微观结构对弧根分布与材料转移的影响规律，揭示弧根运动、弧柱压缩、多层界面结构对能流密度分布、阴阳极热过程的影响机制，构建弓网电弧侵蚀模型，探明弓网电弧能量、聚集形态等对极间材料转移、熔蚀喷溅侵蚀的影响规律，优化弓网电极廓形及微观结构，提出降低弓网电弧侵蚀的方法。

在高速铁路大系统中，弓网关系、轮轨关系、流固关系是三大基础关系。弓网关系决定了高速列车的能量供给，是高速列车能量传递的咽喉。随着列车运行速度提升，当其超过接触网波动速度时，弓网接触状态由柔性向刚性转变，弓网系统冲击振动显著加剧，弓网间电弧频繁，严重影响弓网系统的使用寿命和受流质量。本课题围绕弓网电弧等离子体特性开展相关研究，为提高弓网系统服役性能提供理论基础，主要研究成果如下：. 在弓网电弧特性研究方面：基于弓网弧磁流体动力学模型，探明了横风作用下、降弓过程以及不同列车运行速度下电弧特性及温度场分布情况，解析了电弧等离子体发生、发展特性及动态演化行为；揭示了弓网离线导致的变流器直流侧电压跌落与变流器闭锁的关联机制；搭建了激光莫尔偏折与可见光谱诊断平台，表征了电弧等离子体特性关键参量，提出了燃弧过程中气体组分检测方法。. 在弓网电弧侵蚀行为与调控方面：探明了电极表面能流密度与电弧能量注入的关联机制，解析了电弧作用下的熔池扩展过程以及热侵蚀区域的变化过程，阐明了电极材料在电弧作用下的相变过程；发明了基于弧声信号频谱的弓网接触状态检测方法、基于莫尔偏折的电弧能量分布检测方法、基于超声信号的滑板内部微裂纹分布检测方法。