Purpose.The scientific work is intended to analyse the expansion of the load range and the implementation of regeneration braking (RB) of the direct current drive by using the supercondenser power storage units. Methodology.To solve the problem, we use the methods of the electric drive theory, impulse electronics and the method of calculation of transient electromagnetic processes in linear electric circuits in the presence of super-condensers therein.  Findings.The stiffness of the mechanical and electromechanical characteristics of a series motor is significantly increased, which makes it possible to use a DC drive under load, much smaller than 15…20% of the nominal one. Numerical calculations of the operation process of the supercondenser power storage unit were fulfilled with a sharp decrease in the load of a traction electric motor of a direct current electric locomotive. The possibility of RB of the direct current drive with the series motor is substantiated. The equations of the process of charging and discharging of super-condenser storage unit in RB mode are solved. The authors examined the effect of capacitance on the nature of maintaining the excitation current of an electric motor in the mode of small loads.Originality.The paper developed theoretical approaches for the transformation of soft (mechanical and electromechanical) characteristics into hard ones of DC series motors. For the first time a new, combined method of the series motor RB is proposed and substantiated. Further development obtained the methods for evaluating the storage unit parameters, taking into account the criteria for reliable parallel operation of super-condensers with an electric motor field. Practical value.The proposed and substantiated transformation of soft characteristics into stiff ones allows us to use general-purpose electric drives with series motors and at low loads, and in traction electric drives - to reduce the intensity of electric stockwheel slipping. Thedevelopedmethodofsolvingtransitionalequationsmakesitpossibletotakeintoaccounttherandomnatureofthevoltagechangeonthemotorinsuper-condenserdrivechargeanddischargemodes. The proposed combined method makes it possible to carry out RB at low speeds of the motor armature as well, and thus to increase energy efficiency of operation of electric drives of this type.

This paper deals with the problems of power supply efficiency for non-traction railway customers. Unlike public distribution networks, the non-traction power supply network is within the zone of influence of electromagnetic fields and the conductive influence of the distorted traction current. As a result, poor power quality and additional losses are typical for non-traction railway networks. Subsequently, conflicts due to the low quality of electricity may arise between the railway and its customers powered by the distribution networks of the railway. The influence of a reactive power compensation device on the voltage drop in a non-traction power line is investigated in the article. The implementation of reactive power compensation allows voltage losses during its transmission to the final consumer to be reduced by almost 5% and electricity losses by 3%. Keywords: non-traction consumer, power factor corrector, reactive power compensator, graph of electric network, nodal analysis

Purpose. The main purpose of our work is to develop a method for assessing the heating temperature of the contact area of contact wire with contact strip of pantograph (the contact wire element – the contact strip element of pantograph, in abbreviated form – CWE – CSEP) for parking conditions when preparing the train for the trip with the determination of the maximum current load on given node. Methodology. We proposed to consider the CWE – CSEP contact from the point of view of the classical theory of electrical contact and heating of a homogeneous body. Findings. The features of thermal state of the current collection unit of CWE – CSEP in the conditions of preparing the electric rolling stock for the trip are considered. Within the framework of the study a methodology for assessing the heating temperature of the zone of power sliding contact in the conditions of train preparation for the trip has been developed. The application of the methodology will help reduce the number of burnings through of the contact wire due to the precise choice of the heating/conditioning time of the train for a certain heating/conditioning current when preparing the electric rolling stock for the trip. Originality. It has been established that the reason for burnings through the contact wire in stalls when preparing the train for the trip is the excess of permissible temperature of the power sliding contact as a result of prolonged action of the heating/conditioning current. In contrast to the standard approach for determining the duration of the train heating, the proposed methodology takes into account additional factors, namely, the wear and condition of the contact wire, condition of contact strip of the pantograph. This methodology is based on the classical theory of electrical contact and the theory of heating a homogeneous body, which allows accurate assessment of the thermal state of a power sliding contact, and is convenient enough for use in operating conditions. Practical value. The results of the work are of practical value, since the technology of preparing a train for a trip can be supplemented by calculating the temperature of the CWE – CSEP contact in accordance with the proposed methodology. This will allow applying a set of measures to prevent burnings through of the contact wire in case of possible temperature exceeding the permissible value for a specific train in specific conditions.

W artykule opisano problemy dotyczące wydajności zasilania dla nietrakcyjnych odbiorców kolei. W przeciwieństwie do publicznych sieci rozdzielczych, nietrakcyjna sieć zasilająca znajduje się w strefie wpływu pola elektromagnetycznego i prze-wodzącego zniekształconego prądu trakcyjnego. W rezultacie, słaba jakość energii i dodatkowe straty są typowe dla nietrakcyjnych sieci kolejowych. W konsekwencji mogą wystąpić konflikty spowodowane niską jakością energii elektrycznej między koleją i jej odbiorcami zasilanymi z sieci rozdzielczych kolei. W artykule opisano wpływ urządzenia do kompensacji mocy biernej na spadek napięcia w linii nietrakcyjnej. Wdrożenie kompensacji mocy biernej umożliwia zmniejszenie strat napięcia podczas jej przesyłu do odbiorcy końcowego o prawie 5% oraz zmniejszenie strat energii elektrycznej o 3%. Słowa kluczowe: odbiorca nietrakcyjny, korektor współczynnika mocy, kompensator mocy biernej, graf sieci elektrycznej, metoda potencjałów węzłowych