Modeling electromagnetic safety conditions at railway stations

Abstract

The purpose of the work is to analyze the electromagnetic field generated by the AC traction network of 25 kV at railway stations. The study applies the calculation methods of electromagnetic field intensity and Poynting vector on the basis of determination of the modes of traction power supply system in phase coordinates implemented in the program complex «Fazonord». The calculations of intensities of railway station electromagnetic field show the complexity of traction power supply systems due to the large number of tracks and catenary lines, lasting presence of metal railway cars and tanks on station tracks. Moreover, the distribution nature of the electromagnetic field is influenced by metal pipelines, fences and reinforced concrete passenger platforms. When the power transited through the contact network of the station is 10 + j10 MV·A, which is close to the limiting load capacity of one traction transformer with the capacity of 40000 kV·A, the intensity of the magnetic field at the level of 1.8 m (due to the distribution of the current load on the contact networks of several tracks) is significantly lower than the magnetic field intensity at the haul. The amplitude values of the magnetic field intensity in calculated examples do not exceed 30 A/m. The presence of rolling stock significantly reduces the density of electromagnetic energy flow on passenger platforms, as well as the level of adverse effects of the electromagnetic field on the human body. Cars and tanks positioned on the tracks of the station cause a 2 times decrease in the intensity of electric and magnetic fields. However, the availability of an underground pipeline near the station tracks causes an increase in the magnetic field intensity in the area above the pipeline (due to the currents existing on the pipeline). The article also provides the calculations of field variation in time determined by the train traffic. This allows to obtain the most complete picture of electromagnetic safety conditions at railway stations.