## 1 Introduction
The spectral composition of the reverse traction current is estimated experimentally. Possible electromagnetic interference is determined and its influence on railway automation is estimated. It is shown that external interference in telecommunication circuits is diverse. It is created by vehicles with harmonics and pulses, high-voltage power lines, lightning discharges, as well as various industrial sources of EMF (engines, generators, welding units). The issues of electromagnetic compatibility of track circuits with the TPSSof the railway are considered in [8]. It is shown that track circuits are of fundamental importance for ensuring safety on railways. Therefore, they must be resistant to interference created by external EMF. The results of determining the spectral composition of the traction current are presented. The following results are presented from measurements in track circuits: time and amplitude parameters of the code current flowing in the track threads, input resistance of the track circuit, characteristic resistance and propagation constant. An automated method for measuring track circuit parameters and reverse traction current harmonics has been developed for the laboratory car. It has been shown that harmonics that coincide with the code frequency are unacceptable for track circuits. An algorithm for calculating the electric and magnetic field strengths generated by a DC traction network is proposed in [9; 10]. Analytical relationships are presented that allow calculating the EMF strengths generated by a multi-wire DC electrified railway traction network. The calculation results for a single-wire TS were compared with experimental data. The results of the study of low-frequency electromagnetic coupling between the TN and an underground pipeline in multilayer soil are presented in [11]. A study of low-frequency electromagnetic interference generated by the EMF of the TN on an underground pipeline laid parallel to the road route was conducted. The main attention was paid to the issue of how the soil structure affects the induced stresses. Soil parameters were determined based on field measurements. Soil models consisting of six layers were used. Mutual impedances were calculated using the finite element method and compared with a modified version of the Carson equation, in which the parameter describing the soil conductivity was replaced by a homogeneous equivalent of the multilayer structure. The results showed good agreement between the proposed approach and the reference values, as well as a significant performance gain compared to the finite element method for a multilayer structure. In addition, the modeling allows identifying errors that occur when the soil structure is not properly taken into account, especially when specific resistance is used instead of stratified parameters. A model for assessing the EMF of high-speed railways is proposed in [12]. It is shown that modern European high-speed railways use 2 \(\times\) 25 kV 50 Hz TPSS, which creates significant EMF in the environment. Therefore, it is important to determine the EMF strengths using a model that takes into account frequency and distance. An improved model for EMF of TN is presented. It uses the near-field EMF approach, taking into account the characteristics of field sources and the type of measuring antenna. The simulation results are presented and compared with similar models. Methods of monitoring electromagnetic pollution of the environment on urban railway lines are presented in [13]. In order to meet the daily travel needs of people, urban railway transit lines with 27.5 kV alternating current power supply have been opened in many large cities. At the same time, the metro tunnel under the TPSS will cause changes in the ground potentials due to stray current, which will cause electrochemical corrosion of buried metal structures around the track and reduce their service life.