Controlling and Simulation of Stray Currents in DC Railway by Considering the Effects of Collection Mats

Urban rail transit systems are mostly electrically DC type. Usually in these systems for reducing the costs, running rails are used as the return current paths. Because of the electrical resistance of rails against the flow of traction currents and also rail to ground conductivity (despite rail-to-ground insulations), parts of the return current that flow from trains to traction substations leak to the ground. These leaking currents are called stray currents (as shown in Fig. 1). Stray currents can enter their neighboring metallic infrastructures and, as a result of anodic interactions, cause electrochemical corrosions in their leakage path.