Multiconductor transmission line model for induced stray-currents due to railway systems on ground buried structures

Stray currents generated by electrified railway systems represent a significant source of interference and long-term degradation for ground-embedded metallic structures, including pipelines, reinforcing bars, cable sheaths, and utility networks. Accurate prediction of current distribution and induced potentials is therefore essential for assessing corrosion risk and system reliability. This paper presents a comprehensive multiconductor transmission line model for analyzing induced stray currents on buried structures in the presence of railway traction systems. The proposed formulation treats rails and nearby metallic infrastructures as electromagnetically coupled conductors within a unified framework. The governing equations are derived from the generalized telegrapher’s equations, incorporating longitudinal impedance, transverse admittance, soil resistivity, and mutual coupling effects. The model enables the computation of distributed voltages and currents along extended structures under the train operating condition. Attention is devoted to the coupling mechanisms between traction return currents and adjacent buried conductors, highlighting the influence of soil parameters and electrical bonding conditions. Numerical simulations demonstrate the approach’s ability to predict current leakage profiles and potential gradients. Validation is demonstrated by comparing the computed results with those obtained by alternative circuit models and measurements. The results provide valuable insights for corrosion risk assessment, the design of mitigation strategies, and regulatory compliance in railway environments.