市域铁路信号电缆危险影响及防护方案

Dangerous Effects and Protection Schemes of Railway Signaling Cables in Suburban Railways

市域铁路由于列车运行速度高,多采用AC27.5 k V供电方案。在盾构区域,信号线缆与接触网等强电线缆由于敷设空间有限而距离较近,工程实施阶段必须考虑接触网对信号线缆的危险影响及其防护措施。考虑到隧道壁两侧分别在电缆支架上设置强电及弱电接地圆钢或扁钢,该接地圆钢或扁钢等效于国铁贯通地线。结合盾构区域接触网及信号线缆布置情况,初步计算列车按供电系统的设计最高行车密度运行时接触网电磁感应在信号线缆上产生的磁感应电动势的大小,并定量分析该电磁环境下信号线缆上磁感应电动势不超过60 V的最大允许长度。结合目前各类技术条件以及相关试验数据分析结果,提出市域铁路交流电力牵引区段信号线缆采用双端或多点接地的防护措施及方案。

Due to the high speed of a train,AC27.5 kV power supply scheme is often used in suburban railways.In the shield area,signaling cables,overhead contact lines and other strong electric cables are relatively close due to the limited laying space.Dangerous influence on signaling cables and their protective measures must be considered in the project implementation stage.Strong and weak grounding round steel or flat steel is considered to be installed on the cable supports on both sides of the tunnel wall respectively,which is equivalent to the combined through grounding cable in national railway.Based on the cable layout of overhead contact line and signaling cable in the shield area,this paper introduces preliminary calculation of the magnitude of the magnetic induction electromotive force generated by the signaling cable of electro-magnetic induction of overhead contact line when the train is operating at the highest density on basis of the design of power supply system,and gives quantitative analysis of the maximum allowable cable length considering the magnetic induction electromotive force of not more than 60 V on the signaling cable in the electromagnetic environment.Combined with the current various technical conditions and relevant test data analysis results,a protection measure and scheme for the use of double-ended or multi-point grounding for signaling cables in the AC power traction of suburban railways are proposed.