Subject and Keywords:
The paper presents methods for analyzing the impact of stray currents generated by DC electric traction on nearby earth-return circuits (pipelines). Various simulation models were developed and compared. First the current and potential of the rail were determined using two models. A model with distributed parameters and a model with lumped parameters consisting of chain-connected two-ports of the π type, for which the potential values in the nodes and currents in the branches were determined using the node potential method. The results obtained were used to further analyze the interaction between the railway rail and the pipeline. The pipeline model is presented in the form of a chain connection of π type two-ports. To determine the impact of stray currents on the pipeline, an analysis of the electric field in its vicinity was carried out. For this purpose, two methods have been developed. First, the analysis of the distribution of the scalar potential in the ground for a rail section of finite length was performed. Second method required taking into account the mutual conductivity of the two circuits (rail and pipeline), which in connection with the knowledge of the leakage current from the rail made it possible to determine the potential of the tested pipeline (using controlled voltage sources). The paper presents the implementation of methods and a comparison of the results obtained. The usefulness and applicability of the developed models for the analysis of the impact of stray currents from DC electric traction on earth-return circuits were also assessed.