A Holistic Stray Current Assessment of Bored Tunnel Sections of DC Transit Systems

In considering the stray current design for dc transit systems, the stakeholders should comply with the objective that the stray current design requirement is to minimize the impact of the stray current on the supporting infrastructure and on the third party infrastructure. This paper defines a holistic stray current assessment for bored tunnel sections (BTSs) of dc transit systems, by utilizing a boundary-element platform. The developed method enables the stray current performance of various design options and characteristics to be assessed on the tunnel system. Most important, the methodology proposed offers the means to evaluate the stray current performance of a BTS in terms of its geometry and topology. Finally the postprocessing steps that facilitate the benchmarking of the results against the relevant EN standards are discussed.