Energy efficiency and electric power quality in 220 kV networks supplying traction substations in regenerative braking modes

The use of regenerative braking allows for a significant reduction in energy costs for the processes of transporting goods and passengers; At the same time, the negative impact on the environment is reduced by reducing carbon dioxide emissions. However, recuperation modes are characterized by increased consumption of reactive power by electric locomotives, which leads to a number of negative effects: voltage asymmetry in the networks feeding traction substations increases; active power losses in power lines and transformers increase. To quantify the positive and negative effects of recovery, digital models of the traction power supply system for a double-track section of the railway with 25 kV traction networks have been developed and their operating modes during train movement have been determined. Calculations were performed using the Fazonord software package, version 5.3.4.1-2024 for two regime situations. In the first, regenerative braking was not used, but in the second, it was. The following indicators were analyzed: active and reactive power consumption; voltages on pantographs of electric locomotives; asymmetry on busbars of 220 kV traction substations; losses of active power at the head section of the supply power line and transformers. The results obtained allowed us to draw the following conclusions: in recuperation modes, the total active energy consumption for train movement is reduced by 24…27 %, reactive power consumption increases by 1.6 times; the average voltage values on the current collectors of electric locomotives decrease by 4.4 %. In addition, there is a deterioration in the quality of electricity due to asymmetry and an increase in active power losses in transformers and power lines. The proposed technique is universal and can be used to analyze the modes of power supply systems of various structures and designs.