Purpose. To conduct research of electric motors in order to obtain the results that will assess the degree of energy saving due to electric loss reduction in the equipment with non-controlled electric drive. Methodology. The paper proposes an engineering method for determination of active power losses in the motors of the equipment with non-controlled electric drive in locomotive depot during load changes on the motor shaft. It is necessary to analyse the reduction of active power losses in the motor and the power supply network when an under-loaded motor is replaced with a motor having less power. Findings. After the calculations performed by the authors, it was found that for electric motors, in case of reducing the load factor from 0,7...0,75 to 0, 4...0,5 active loss reduction after the motor replacement for the less powerful one ranges from 0.58 kW to 2.865 kW. Also, the calculations were carried out on the example of electric motors with a lower synchronous speed, the effect of under-loaded motor replacement increases in terms of active power loss reduction. The greatest effect is achieved when the load factor is 0.55 l k ≤. Originality. For the first time the paper outlines the issues of energy saving efficiency for the equipment with noncontrolled electric drive in locomotive depot by replacing the under-loaded motors with the less powerful ones. As long as there is a significant amount of the considered electric drives, it may cause severe losses, taking into account the peculiarities of their operation. Practical value. The obtained research results allow us to solve the problem of replacement of under-loaded motors in locomotive depot equipment with the motors having less power as efficiently as possible in terms of reducing electric losses. For instance 90-kW motor of a washing machine can be replaced with 75-kW motor when the load factor is 0.7 l k ≤ , this can significantly reduce the performance losses. This method can be applied not only in locomotive depot but also for all equipment with non-controlled electric drives that operates in under-load mode.

Purpose. The article aims to study the problem of increase the reliability of auxiliary machines for AC electric trains during operation in real conditions. Methodology. The peculiarity of system construction of auxiliary machines for AC electric rolling stock is the use of asynchronous motors for general industrial purpose. An engineering method of influence determination on the feeding voltage asymmetry and its deviation from the nominal value on heating of auxiliary machines insulation was proposed. Findings. It is found out that in case when the auxiliary machines of AC electric trains work under asymmetry factor of the voltage 10% or more and feeding voltage deviation from the nominal order 0.6 relative unit then it is possible the overheat of their isolation, even if it has class H. Originality. For the first time the issue of the total insulation heating under such boundary parameters combinations of energy quality, when each of them contributes to the heating insulation increase as compared to the nominal regime of the "rotating phase splitter−auxiliary machinery" system was illuminated. Practical value. Conducted research allow us to establish the boundary parameter values of feeding energy quality (asymmetry factor, feeding voltage deviations from the nominal value), at which additional isolation overheating of this class under the effect of specified factors will not exceed the agreed value.

This paper deals with the problems of enhancement of registration and distribution of electric energy which can be obtained from DC electric locomotives by the regenerative braking. According to theoretical researches, it is possible to return approximately 8 - 12% of electric energy which is consumed for electric traction by using of a regenerative braking mode. However in recent years for electric traction networks of JSC “Ukrainian Railways”, this index doesn’t exceed 2.6%. So we consider that the regenerative braking is one of the most prospective ways for energy saving in electric railway transport. Results of the experimental researches which were executed on DC traction substations and VL11M6 electric locomotives are described in this paper. Instantaneous values of voltage and current in different modes have been obtained. The electric energy balance for experimental zone has been performed. Also the ways of distribution and consumption of energy of regenerative braking mode have been analyzed. On this basis of the executed investigations, recommendations about providing of supercapacitor energy storage system for Ukrainian railways are proposed.

The purpose of this work is to study the utilization efficiency of electric driving energy-saving motors of non-standard technological equipment meant for repair of railway rolling stock, in terms of improvement of energy performance, i.e. improvement of efficiency factors and power factors, and decrease of power losses as compared with the most commonly used “conventional” asynchronous motors. There are two options for improvement of the energy performance of electric drives of non-standard technological equipment: replacement of a conventional motor with an energy-saving one similar in terms of nominal voltage, rotational speed, power, etc.; changeover of stator winding from “delta” to “star”. A special technique has been proposed to determine the effectiveness of this changeover in terms of improvement of energy indicators. Comparison of the real values of the energy indicators of conventional motors and energy-saving motors in the case under consideration is required to perform the technical and economic calculations when solving the problem of the expediency of replacement of conventional asynchronous motors with energy-saving motors in the abovementioned equipment.

The paper presents the results of bench tests of wear resistance of contact inserts of current collector runners made of «ROMANIT-UVLSh» material and their effect on the wear of the copper contact wire is evaluated. This material is a composite with a high content of electrically conductive lubricants capable of forming a thin conductive transition layer in a friction pair. Low temperature in the contact zone, indirectly, indicates a low transition resistance and high energy performance of the sliding contact, and low wear of the contact wire confirms its high tribological and mechanical properties. The use of contact inserts runner's current collectors made from this material is possible, both in alternating and direct current and can provide higher technical and economic indicators in comparison with traditional materials.