Reduction of electrical energy losses of power transformers of 25 kV traction substations

The aim of the study is to reduce the losses of electrical energy in power transformers of AC traction substations. To reduce the losses of electrical energy, interval counterregulation of performance indicators in the traction power supply system is performed. The planning of the electrical energy losses is determined by the predictive time intervals. The electrical energy losses in the time interval are determined by the power losses of instantaneous circuits. Instantaneous circuits determine the voltage of the windings of transformers, the currents of the power supply arms of the electric traction network, the transformation ratios, the temperature of the windings and the power of regional loads. The predictive values of the instantaneous circuits are determined by the results of the monitoring of the completed train schedules, statistical analysis and simulation modeling of the operation of the traction substation. The initial data for the calculation are the predictive discrete values of the performance indicators of the traction power supply system. The calculation of power losses in steel in power transformers is performed taking into account voltage unbalance. Copper losses are determined in phases, taking into account the distribution of arm currents in the windings and the actual transformation ratios. Actual transformation ratios are determined based on the voltage control stage. The effect of winding temperature on power losses is taken into account by the temperature coefficient of resistance. The number of transformers in operation at the predictive time intervals is selected by the minimum loss of electrical energy. The accuracy of the choice of the number of transformers in operation is checked by analyzing the implementation of the forecast train schedule. The error of the initial data and simulation modeling is determined by comparing the predictive values and the monitoring results. It is proposed to carry out performance management of the traction power supply system on the basis of digital technologies.