Energy accounting in AC substations in case of transit currents flowing through the contact network

The purpose of the work is to clarify the methodology for determining the electric power consumption of traction substations of AC electric power for the transit of external power supply. The conditions for the emergence of significant transit through traction networks of external power supply are revealed. Using the example of the Ushaped scheme for the replacement of power transmission lines, it is shown that the intersystem power fluxes along the electric power transmission lines of the external power supply exert the greatest influence on the transit currents along the traction networks. For analysis, the local and transit components of the power flow are identified and a typical section of the electrical network is considered, containing three electrical connections at voltages of 330, 110 and 27.5 kV. In this case, the most significant factor affecting transit through the traction network is the transverse component of voltage drop, since its compensation in this network is difficult. Methods for estimating the transit current of a traction network are given. An engineering technique for estimating the electric power consumption for transit by software is proposed. Authors show the necessity and possibility of using the KORTES package for estimating transit currents of the traction network caused by external power supply. The results of calculations for two sections of different railways based on the data of the Regional Dispatch Office are presented. The influence of regional and traction loads on the path of transit currents is considered. Obtained relationships and developed methodology allow estimating the electric power consumption of traction substations for the transit of the power of external power supply.