Purpose. Improving the efficiency of passenger traffic on non-electrified sections of the railway of Ukraine by optimizing the structure and creating principles for building a traction electric drive of a promising autonomous electric train powered by traction engines from the system of onboard storage of electricity. Methods. The methodological basis of the study are the general theoretical provisions and principles of the system approach of theoretical electrical engineering, theoretical mechanics, theory of electrical machines and converters. The basic principles of management theory and the basics of decision theory are used. Results. The general principles of construction of the traction electric drive of the perspective autonomous electric train with power supply of traction engines from onboard energy storage devices are formulated. The functional scheme of the traction electric drive of the perspective autonomous electric train is offered, the analysis of work of the electric drive in the modes of traction and regenerative braking is carried out. The mass parameters of two types of energy storage devices, namely electrochemical batteries and supercapacitors, have been determined. The basic requirements to the system of automatic control of the traction drive of the electric train are formulated. It is shown that in the future the use of autonomous battery electric trains will be technically possible and economically justified on non-electrified sections of Ukrzaliznytsia.