The 25 kV traction network creates highly intensive electromagnetic fields. These fields affect the long conductive structures located near railway lines and can induce voltage, posing a danger for maintenance personnel. Typical examples of such structures are pipelines, which are used to transport liquid and gaseous products. In addition to compromising electrical safety, the induced voltage can result in dangerous densities of corrosion currents in pipe insulation defects. Therefore, the determination of the induced voltage and current in the pipes is undoubtedly relevant. An analysis of existing literature on the electromagnetic compatibility of traction networks and pipelines indicates that important aspects regarding the effects of traction networks and high-voltage power lines on extended conductive structures have been addressed. However, these works do not present a unified method to determine the induced voltage on parts of the structures and the current flowing through the pipeline. Such a method could be based on a technology that models the operation of electric power systems in phase coordinates. This paper presents the development of a method and the results of the studies aimed at modeling the voltage induced by complex traction networks. The developed digital models make it possible to adequately determine the induced voltage created by multi-wire traction networks and the current flowing through the pipes. Using these models, one can make an informed decision regarding the appropriate measure to ensure the safety of personnel working on these structures, as well as the development of corrosion prevention methods and measures.

Upgrading of traction power supply systems will be required to transfer electrified railway lines to high-speed traffic. Coaxial cables and balancing transformers can be used as technical upgrading means. The article presents the results of computer simulation in the Fazonord software complex of the traditional 2x25 kV traction system, as well as systems with coaxial cables and Woodbridge symmetric transformers. Simulation results showed that the use of cables contributes to a significant increase in the level of voltage on current collectors of electric rolling stock. Use of modified Woodbridge transformers makes it possible to reduce the imbalance coefficient by the reverse sequence on high voltage buses of traction substations. However, the reduction is insignificant and depends on the modes of movement of trains in adjacent inter-station zones. The biggest positive effects occur in the integrated application of balancing transformers and coaxial cables.

Rectifier locomotives have non-linear current-voltage characteristics and generate higher harmonics (HH) in the power supply networks, which is accompanied by the following negative effects: reduced equipment service life, distortion of electricity metering, occurrence of resonant processes, etc. Therefore, the problem of reducing the levels of harmonic distortion in the networks adjacent to the traction substations of the AC railways is of increased relevance. The level of HH generation depends on the design features of electric locomotives. Electric stock with zone-and-phase regulation creates high harmonic distortions, which results in increased losses, increased electromagnetic effects on adjacent power and telecommunication lines and reduced reliability of power supply. Electric locomotives with asynchronous traction motors (ATM) connected via 4q – S converters virtually do not distort the sinusoidality of the current curve. To measure the degree of reduction of harmonic distortion during the movement of locomotives with ATM, simulation modeling of non-sinusoidal modes of a typical 25 kV traction power supply system was carried out for two variants of the locomotives used: 1) VL-80R with DC motors; 2) UTY –1 with asynchronous traction motors. The methodology for determining non-sinusoidal modes is based on the technology of modeling electric power systems (EPS) in phase coordinates; at the same time, the models of EPS elements were formed as lattice schemes characterized by a fully connected topology. The parameters of these circuits can be recalculated to the frequencies of HH. The proposed approach is universal and can be used to study non-sinusoidal modes in existing and future traction power supply systems. The simulation results showed that the problem of increased harmonic distortion in the networks feeding the traction substations can be completely solved by replacing the acting locomotives with new-generation electric locomotives with asynchronous electric drives and four-quadrant converters.

The article presents the simulation results of electromagnetic effects of a 25 kV electric traction network on a steel pipeline with a pipe diameter of 250 mm. It is shown that a pipeline with insulating pipe coatings can induce stresses dangerous to operating personnel. At certain points of the pipeline, grounded on both sides, the magnitude of the induced voltage can reach 116 V with an approach width of 100 meters. Therefore, it is required to develop and implement special measures to protect operating personnel. With an increase in the approach width to 400 m, the maximum values of the induced voltages did not exceed the permissible level. In modes of short circuits in the electric traction network, the induced voltages in the pipeline may briefly exceed 500 V. The highest voltages are observed at points located near the short circuit point. In case of short circuits at the terminals of the traction substations, the magnitudes of the induced voltages are reduced to 75 V. To reduce the induced voltages, the following measures can be assumed: reducing the length of parallel passage sections of pipeline and railway, increasing the approach width, installing additional groundings. During the operation of the structure, the magnitude of the “pipe-to-ground” transition resistance may decrease, which will result in a decrease in induced voltages.