Evaluation of metro stray current corrosion based on finite element model

Corrosion and stray currents at urban track infrastructure

“…This current, called stray current, finds the way of lower electrical resistance by which it will return to the source of electricity (Figure 6) [23,24]. At places where the current leaves the rail, the corrosion processes will additionally be accelerated due to the action of stray currents [17]. The current released from the rail passes through the soil and enters a neighbouring embedded metal structure, such as a metal pipeline, and uses this medium as a return path to the source.…”

“…In modern railway systems, the measures used to reduce the effects of stray currents at the source can be divided according to the following two groups of parameters that define the level of stray currents [17,33]:…”

“…If a vehicle moves at uniform speed or decelerates without the possibility for regenerative braking (return of electricity to the supply grid using engine as generator during braking activity [16]), its electricity consumption will be minimum, and hence stray currents will also be minimum. On the other hand, the consumption of electricity increases with acceleration, which will result in higher stray current values [17,18]. When a vehicle accelerates, the quantity of stray currents will also depend on vehicle acceleration rate, i.e.…”

“…When this system is used, high voltage can be generated in the rail which might jeopardise safety of rail infrastructure users. This can be solved by using voltage limiting device [16,17]. In floating system, during return of electricity from the vehicle to the electrical substation, the electric voltage in the rail will appear as positive as the soil in near the rail vehicle, and negative in the vicinity of the electrical substation.…”

“…In floating system, during return of electricity from the vehicle to the electrical substation, the electric voltage in the rail will appear as positive as the soil in near the rail vehicle, and negative in the vicinity of the electrical substation. The distribution of voltage along the rails will define points where stray currents will occur [17,18]. GRAĐEVINAR 72 (2020) 7, 593-606 Katarina Vranešić, Stjepan Lakušić, Marijana Serdar…”