城市轨道交通杂散电流治理的综述与评估

杂散电流会造成电气化交通系统附近金属结构腐蚀,该现象在普遍采用直流牵引供电的城市轨道交通中尤为突出.该文分别对城市轨道交通新建线路和运营阶段的现有线路的杂散电流治理和防护措施进行讨论.对设计阶段的新建线路而言,可采用包括优化牵引变电所位置、减小轨道纵向电阻、在道床中安装杂散电流收集系统等措施.对处于运营阶段的现有线路而言,除了采取在走行轨上并联线缆或走行轨间焊接均流线等以增大回流路径截面积措施外,通过电力电子的静止变换器(如负阻变换器等)控制回流路径杂散电流的方法也是极具潜力的治理措施;上述单元可以部署在特定点,以实现对轨道电位过高或出现初期腐蚀位置处的定点治理.

Review and Evaluation of Stray Current Mitigation for Urban Rail Transit

Stray current causes inevitable corrosion to structures near electric transportation systems, especially in DC urban rail transit. The paper considers the issue of stray current mitigation discussing what can be done for design and existing systems, sticking to applicable standards and consolidated protection practice. Mitigation measures may be devised for a new constructed system, such as the optimization of traction substation positions, reducing the longitudinal resistance of the running rails and return circuit, and using an additional stray current collection system (to be included in the track bed during construction). As for an existing system, besides increasing the total cross section of the aforementioned return circuit and stray current collection system by adding parallel conductors or cross-bonds, it is recommended to employ static converter units (e.g. negative resistance converters) to control the stray current in the return circuit. These units can be deployed in specific points where analysis or measurement indicates the large rail potential or incipient corrosion is spotted out.