Investigating the impacts of high voltage powerlines on ground current fields

Abstract

Stray currents are a typical problem of areas crossed by electric railways. This well-known phenomenon can cause significant damage to all underground metallic installations, especially in case of DC stray currents. In areas close to the railway, the presence of stray currents is expected, and protective measures are applied to all sensitive installations like pipelines. However, field measurements have shown that the presence of high voltage power lines can significantly affect the ground current field due to the well-grounded ground wire representing an excellent alternative path for ground currents. This way, stray currents can appear in areas where the presence of ground current field from DC traction is normally not expected. Preliminary simulations have confirmed that high voltage power lines are a significant element affecting the spreading of ground current and the presence of high voltage power lines must be considered when investigating the ground current field of an area. However, these simulations were performed only for a limited area with a very simplified geometry of railway truck and a single power line. This paper presents results of a more complex simulation involving a large area crossed by a DC railway traction system and a complex high voltage network. The simulation is based on real topology representing an area around the town of Zilina, an industrial area with a complex high voltage network and an important railway hub.