## 1 Introduction
The change in ground potential leads to a potential difference between different substations, which causes the phenomenon of neutral displacement of transformers. A tunnel model has been developed that allows calculating the EMF in the tunnel and assessing the factors of influence and induced voltage on its metal structures. Current issues of transport safety are considered in [14; 15; 16; 17; 18]. The results of modeling the distribution of EMF of an overhead power line are given in [19]. In order to develop measures to reduce the magnetic field strength near the power line, which can interfere with the operation of electronic equipment, a method for modeling the EMF of a power line based on MEMS technology is proposed. It was used to design a sensor that is used as a probe to determine the distribution of EMF of an overhead power line. Based on the obtained measurement results, the EMF of the power line was modeled. The experimental results showed that the magnetic field strength near the edge of the power line is higher than in the central region. The EMF model for analyzing overvoltages in the direct current TPSS of light rail transport is proposed in [20]. The problem of protection against overvoltages of atmospheric origin for modern TPSS of light rail transport is considered and a model is proposed that enables the estimation of the EMF strength. The field was modeled in the time domain using a plane wave. The method of characteristics was used to solve the resulting system of partial differential equations. Several modeling options were performed to determine the optimal arrangement of arresters for overvoltage protection. The analysis of the magnetic field of electrified railways passing near hospitals was carried out in [21]. The characteristics of the EMF of traction networks operating at a frequency of 16.7 Hz are presented. TN with different spatial arrangement of conductors and the magnetic field created by them were compared. In relation to the maximum traction currents, the minimum distances between TN and hospital buildings were determined, ensuring the trouble-free operation of sensitive electromedical devices. In case of exceeding the permissible limits, additional measures for mitigating magnetic fields in hospitals located near electrified railways are described. The results of the study of EMF associated with power transmission lines in the state of Kuwait are presented in [22]. The data on EMF obtained from the observation, calculation, and analysis of the EMF of power transmission lines are presented. The measurement results were compared with international standards. The measures to limit the impact of EMF are described. The data on electromagnetic studies of alternating current power transmission lines are presented in [23]. With the implementation of projects for ultra-high voltage alternating current power transmission lines, the impact of man-made EMF on the environment and human health increases. A 500 kV power transmission line is considered for modeling EMF using the finite element method. The distribution of EMF under the power transmission line was analyzed using a human body model. The results showed that EMF intensities decrease with increasing distance from the wires, and the characteristics of the distribution of intensities in different parts of the human body vary significantly. Transient electromagnetic fields associated with a power transmission line above the ground with losses are considered in [24]. A procedure for calculating the EMF near power transmission lines is presented. By decomposing the power transmission line into a series of Hertzian dipoles, it is possible to find the electric and magnetic fields at any point above the ground, summing up the contribution of each segment. Two analytical approaches in the frequency domain are implemented for calculating the EMF from a horizontal electric dipole located above the conductive ground. The results of the study of the EMF model for overhead power transmission lines are presented in [25].