【作者】 于凯；

【导师】 朱峰；

【作者基本信息】 西南交通大学 ， 电气工程， 2015， 硕士

【摘要】 地铁是缓解城市交通压力、促进城市化进程的有效工具。地铁在带给人们交通便捷的同时也存在诸多问题,其中直流杂散电流对地铁结构基础及周围金属结构的电化学腐蚀是危害较大的问题之一。为了进一步明确地铁杂散电流的相关特性以减小其腐蚀危害,本文利用专业软件CDEGS进行了系统的仿真模拟研究。利用该软件中的MALZ模块建立了地铁三维立体隧道模型；通过与电阻网络模型理论结果、模拟实验结果以及现场测试数据的对比验证了所建模型的适用性及正确性；在该模型的基础上模拟研究了双边供电方式下参数连续分布和离散分布时的杂散电流的静态特性以及在不同负荷下的动态特性；定义了排流网的排流效能并通过仿真分析了排流效能的影响因素；基于该模型利用直流伏安法对轨-地过渡电阻进行了仿真测试得到了影响过渡电阻的因素及其影响关系。通过该系统的仿真研究及理论分析得到以下结论：结构钢筋、排流网不同钢筋之间的电流在数值上存在差异,靠近轨道的钢筋易受腐蚀；轨道纵向电阻部分变大对杂散电流的影响是“段作用”,轨道绝缘损坏对杂散电流的作用是“点”作用,实际中要格外重视轨道纵向电阻的变化；轨道不论排流与否都处于受腐蚀状态,尤其是区间中间部位的腐蚀情况最为严重；排流网的排流效能与是否排流关系不大,且排流时杂散电流总量是不排流的近4倍；采用集中分布方式、排流网尽可能靠近轨道将有利于提高其排流效能；区间过渡电阻主要集中在轨道绝缘层上,保持轨道绝缘层良好是提高过渡电阻唯一可靠的方法。更多还原

【Abstract】 Metro is an effective tool to ease the urban traffic pressure and can promote the urbanization. It brings people convenient transportation and also has many problems. The DC stray current corrosion on the structural basis and surrounding metal structure is one of the larger harmful problems.It is necessary to further clarify the relevant characteristics of the metro stray current in order to reduce the stray current corrosion. In this paper, the professional software CDEGS was used to simulate the metro stray current. With the module MALZ in the CDEGS, a realistic Three-dimensional tunnel model was established. By comparison with the results of the resistor network analysis method, the model was validated to be correct. On the basis of this model, the static characteristics of stray current was simulated in the continuous and discrete parameters and also the dynamic characteristics was simulated in different load. The efficiency of the drainage net was defined and analyzed the factors affecting the efficiency of the drainage net. On the basis of this model, the rail to earth transition resistance was tested and found the factors affecting the transition resistance.The following conclusions were reached through the systematic simulation:The current flowing in the different rebar of the structural steel mesh and the drainage net was different in value, the metal near the rail was more susceptible to corrosion. That the part of rail longitudinal resistance increase has a "segment" effect on the stray current and the part of rail insulation damage has a "point" effect on the stray current. The rail is in corroded state no matter draining or not and corrosion in the middle of it is most serious. That drainage or not has little influence on the efficiency of the drainage net and the amount of stray current in draining state was nearly four time than not drain. That use the centralized distribution method and let the drainage net near the rails can improve the drainage net efficiency. The transition resistance mainly in the rail insulating layer and keeping the rail with good insulation was the only way to improve transition resistance更多还原