An analysis of tasks on improving energy efficiency of electric traction systems reveals the need for the introduction of new technologies, namely modern rolling stock with a traction asynchronous electric drive, as well as traction substations, based on new technologies. To solve this class of problems, we have defined the need for an integrated simulation model of the electric traction system that would ensure a sufficient level of its reliability.This work reports details of algorithms for calculating the parameters in order to develop a simulation model of the integrated electric traction system of an underground rail system, which consists of electricity supply subsystems, electric drive of rolling stock, and mechanical part of the traction transmission.In the programming environment Matlab/Simulink, based on the known, actual and refined, estimation parameters, we developed a simulation model of the system of traction electric supply to an underground rail with a two-way power to two tracks. We have constructed a simulation model of the modern traction electric drive of the underground rail cars with a vector system to control an asynchronous electric drive and a uni-mass mechanical part, capable of taking into consideration the impact of the coefficient of adhesion.We have compared results from the imitational simulation of dynamic processes with oscillograms for the actual operation modes of an underground rail system, which confirmed the adequacy of the model to the examined object. The correspondence between results obtained from simulation is confirmed by the oscillograms from analysis of voltage and current of the contact network, as well as by characteristics of the traction and braking modes of rolling stock.We have simulated processes of work of the power supply system, a nonstationary regime at deterioration of adhesion conditions, and a recuperative braking mode with energy transferred to other trains.Using the developed model of the integrated system of electric traction would contribute to a more detailed study into the mutual influence of elements in the electric traction system. That would make it possible to improve the efficiency of making technical decisions related to meeting safety requirements, preventing the disruptions of normal operation, and bringing down operating costs