Modeling of highly structured electromagnetic fields occurring in places of intersection of traction networks and electric power transmission lines

At the intersection of the routes of alternating current electrified railways with high-voltage overhead electric power transmission lines, complex electromagnetic fields arise, which are characterized by increased levels of intensity. Such electromagnetic fields can interfere with the functioning of electronic equipment and telecommunication systems. Besides, there may be a negative impact on personnel serving the railway infrastructure facilities. The article presents the results of computer research conducted in relation to a complex traction network of 25 kV, in parallel with which a 220 kV electric power transmission line passed. The structure of the vehicle included a line with a grounded phase, the wires of which were mounted on the supports of the overhead contact system. The electromagnetic field was simulated at the orthogonal intersection of the described multi-wire traction network with a 500 kV electric power transmission line. Two operational situations were considered: the normal mode of operation of a 220 kV electric power transmission line with a power transmission of 25 + j16 MV·A and a one-phase break at the starting end with the transmission of the same total power. Calculations of electromagnetic field intensities were performed in the Fazonord software package. On the basis on the simulation results, volumetric diagrams are constructed that clearly illustrate the complex structure of the occurring electromagnetic fields. These diagrams will help one to make informed decisions on protecting personnel and electronic equipment (in particular, railway automation and telemechanics devices) from the negative effects of electromagnetic fields. In normal operation, the maximums of the electric field for the considered intersection exceed the permissible values for electrical personnel. Magnetic field intensities are within acceptable limits. When the phase wire of the 220 kV electric power transmission line breaks, an increase in the magnetic field strength is observed for coordinates located on an axis perpendicular to the road route and lying within the range of 0–30 m. The studies were financially supported by a grant from the State Ministry of Education and Science of the Russian Federation on the topic “Improving the quality of electric energy and electromagnetic safety in electric power supply systems of railways equipped with Smart Grid devices by applying methods and means of mathematical modeling on the basis of phase coordinates”.