Abstract <p>Based on an analysis of the parameters of the traction power-supply system of a real intersubstation zone, an algorithm for calculating the traction network resistance was constructed. To determine the reserved values of voltages and currents of the traction network, a scheme for installing devices for collecting data at traction substations was proposed; based on these data, a change in measured values depending on instantaneous schemes was obtained. Based on the available real data, a traction-network section was simulated, on the basis of which the traction network resistances was calculated. To determine the voltage drop and complex resistance of the traction-network section, calculations of the traction power-supply-system modes were carried out in a simulation model. High convergence of voltage losses in the traction network and the calculation results in the software package was shown.</p>