Browsing by Author "Mukha, Andrii M."

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    Determination of Energy and Electric Capacity of On-Board Supercapacitor Regenerative Energy Storage
    (Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2021) Kostin, Mykola O.; Mukha, Andrii M.; Sheikina, Olha H.; Kurylenko, Olena Ya.
    ENG: Purpose. Development of a method for determining the main functional parameters of on-board supercapacitor recuperative energy storage based on the asymptotic theory of extreme statistics by Gumbel, taking into account sto-chastic nature of changes in recuperated voltage and current. Methodology. To achieve this purpose, methods, devices and computer systems for temporary registration of recuperated voltages and currents on operating electric locomotives, methods of the theory of random processes and methods of probabilistic and statistical processing of registro-grams of voltages and currents were used. Findings. A computational and experimental method for estimating recu-perative energy has been proposed and practically applied. A probabilistic method has been developed for determining the energy and electric capacity of on-board supercapacitor recuperative energy storage units. Numerical probabilistic and statistical calculations of the energy and electric capacity of on-board storage for the VL8 and VL11M6 electric locomotives during their operation in the sections of Prydniprovska railway have been carried out. It was found that the energy and electric capacity of on-board storage devices are distributed according to an exponential law with a clear prevalence of their minimum values and in compliance with direct proportionality between them. Originality. For the first time, an autonomous phase of recuperative braking mode of an electric rolling stock has been developed, which makes it possible to significantly reduce the mass and dimension of a supercapacitor storage. The asymptotic theory of extreme statistics by Gumbel was adapted to the method for calculating energy and electric capacity of an on-board storage device, which made it possible to take into account the influence of stochastic nature of changes in the recuperated voltage and current. The probabilistic influence regularities of the change nature in the recuperation energy on the capacity of on-board storage in the phase of recuperative braking have been established. Further development was obtained by a computational-experimental method for assessing the recuperative energy, based on monitoring and using the time dependences of voltage and current obtained in real modes of recuperative braking. For the first time in electric traction systems, it was proposed to carry out the transition from the recuperative braking mode to the recuperative regeneration mode. Practical value. The developed method and technique based on it make it possible to evaluate functional parameters of on-board storage device of all types of electric rolling stock, considering stochastic nature of recuperated voltages and currents. Numerical-graphic dependences of the energy in-tensity and capacity of the on-board storage are recommended for predicting and evaluating these parameters for various modes of recuperative braking. Since the task of designing an on-board storage unit (in terms of mass and dimensions) is ambiguous, therefore, in each specific case of the type of electric locomotive and recuperation modes, it must be solved individually, taking into account the probability of the corresponding capacitance values.
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    Development of a Method of Calculating the Temperature of a Survey Assembly When Preparing a Train Dispatch
    (Львовский политехнический национальный университет, Львів, 2020) Ustymenko, Dmytro V.; Kuznetsov, Vitaliy; Marenych, Oksana L.; Kovzel, Maksim; Mukha, Andrii M.; Sinkevych, Oleksiy; Tryputen, Mykola; Al Said Ahmad, Mohammad Ahmad Diab
    ENG: The features of the thermal state of the current collection unit «contact wire – contact insert of the current collector» in the conditions of preparation of electric rolling stock for the journey are considered. As part of the study, a methodology has been developed for estimating the heating temperature of the power sliding contact zone in the conditions of train preparation for journey. Application of the method will help to reduce the number of «burnouts» of the contact wire due to the exact selection of the heating/cooling time of the train for a certain heating/conditioning current when preparing the electric rolling stock for the journey. It was established that the cause of the «burns» of the contact wire in the parking lots when preparing the train dispatch is the excess of the permissible temperature of the power sliding contact as a result of the prolonged action of the heating/conditioning current. The standard approach for determining the duration of heating is based on the average values of the loads on the system and therefore does not take into account some factors, for example, the state of the contact wire, the state of the contact insert of the current collector, the number of cars in the train, and so on. The proposed technique is based on the classical theory of electrical contact and the theory of heating a homogeneous body, which makes it possible to accurately assess the thermal state of the power sliding contact and convenient enough for use in operating conditions. The results of the work are of practical value, since the technology of preparing a train for dispatch can be supplemented by calculating the contact temperature «contact wire element – contact insert element» in accordance with the proposed methodology. This will allow for a specific train in specific conditions to apply a set of measures to prevent «burnout» of the contact wire in the event of a possible temperature exceeding the permissible value.
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    Nanostructures in the Formation of the Properties of High-Current Sliding Electrical Contacts on the Electric Rolling Stock
    (Igor Sikorsky Kyiv Polytechnic Institute, 2019) Ustymenko, Dmytro V.; Mukha, Andrii M.; Baliichuk, Oleksii Yu.; Kurylenko, Olena Ya.; Romanov, Serhii; Sabiev, Tamerlan
    ENG: 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.
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    Reactive Power Compensation for Non-Traction Railway Consumers
    (Institut Kolejnictwa, 2020) Mukha, Andrii M.; Bondar, Oleh I.
    ENG: 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%.
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    Reactive Power Compensation for Non-Traction Railway Consumers (preprint)
    (Institut Kolejnictwa, 2020) Mukha, Andrii M.; Bondar, Oleh I.
    ENG: 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%.
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    The use of Innovative Contact Strip for Pantographs of Electric Rolling Stock. Experience in Operational and Bench Tests
    (De Gruyter Open Ltd, Germany, 2021) Mukha, Andrii M.; Ustymenko, Dmytro; Al Said Ahmad, Mohammad Ahmad Diab; Kuznetsov, Valeriy; Skrzyniarz, Marek; Szulc, Waldemar
    ENG: Modern high-tech composite materials are widely used in various sectors of the economy, in particular, in railway transport. Among the areas of application of such innovative materials, the manufacturing of contact strips for pantographs of electric rolling stock should be mentioned. Innovation is primarily understood as the self-lubricating property of the working surface of the linings. The linings made of such materials differ from the traditional graphite (coal) ones by the increased content of metal additives, in particular copper, which limits the possibility of their use on electric rolling stock in the countries of the European Union. Regulatory restrictions on the content of copper (35% and 40%) are associated with possible damage to the contact wire, in the case of using overlays with a content of copper (metals) greater than these restrictions. On the railways of Ukraine (countries of the former USSR), there are also restrictions on the use of linings of different types according to the degree of wear of the contact wire, no more than 40 microns is allowed per 10 thousand passes of the locomotive pantograph along the contact wire. These standards are verified during operational and bench tests. The aim of the article is to present the types of tests and compare the obtained values with similar indicators in the case of using a traditional contact strip for pantographs of electric rolling stock. The results obtained confirm the possibility of using innovative linings on iron networks, since the wear of the contact wire during testing is much lower than that of the normative and knife than for traditional types of linings. In addition, during a set of tests, the fact of improving the quality of the working surface of the contact wire was established, which positively affects the extension of the service life of the contact wire.