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Item 2-х режимний тягово-левітаційний модуль перспективної магнітно-левітаційної транспортної системи(Кременчуцький національний університет імені Михайла Остроградського, 2022) Плаксін, Сергій В.; Муха, Андрій Миколайович; Устименко, Дмитро Володимирович; Шкіль, Юрій В.; Голота, Олександр Олександрович; Чуприна, Єгор М.Show more UKR: Сучасний електрорухомий склад має можливість розвивати швидкості руху понад 500 км/год, що створює умови для конкурентної боротьби з іншими видами транспорту на малих та середніх відстанях. Такі високошвидкісні системи на базі ефекту магнітної левітації можуть використовувати електромагнітну або електродинамічну підвіску. Перша вимагає високої точності побудови шляхової структури та складної системи управління, а друга менш критична до точності побудови шляхової структури та рівня складності системи управління, але ефектний підвіс магнітоплану створюється лише на відносно високій швидкості руху. На початкових, розгінних ділянках поїзди з електродинамічним підвісом підтримуються в робочому положенні за допомогою спеціальних колісних систем, що є суттєвим недоліком. Метою досліджень є визначення можливих схемних рішень шляхового модуля, який може забезпечувати комбінований режим роботи – режим тяги та режим левітації, не тільки у сталому режимі руху, але й на ділянках розгону чи гальмування без використання опорних колісних систем. В статті представлені деякі результати розробки тягового-левітаційного модуля на базі дворежимної шляхової структури, яка може працювати зі зміною полярності (напрямку) магнітного потоку, який взаємодіє з магнітним потоком надпровідних магнітів встановлених на магнітоплані. За результатами досліджень представлені схемні та конструктивні рішення науково-обґрунтованого тягово-левітаційного модуля для магнітнолевітаційної транспортної системи типу Маглев, з можливістю отримувати левітацію магнітоплану на розгінний ділянці.Show more Item Analysis of Operational Characteristics of SRM in Emergency Modes of the Converter Unit(IEEE, 2022) Vlasenko, Vladimir; Tytiuk, Valerii; Kuznetsov, Vitalii V.; Kuntush, Yelena; Chornyi, Oleksii; Busher, VictorShow more ENG: The paper analyzes the issues of maintaining the operability of a switched reluctance motor (SRM) in various emergency situations. The researches were carried out using simulation modeling in the Matlab environment, the developed model was used for both normal and emergency operation modes. A series of dynamic tests of the motor torque has been carried out, and the values of the electromagnetic torque pulsation coefficient have been calculated. The possibility of maintaining the operability of SRM in the event of various emergency situations in the phases of the motor has been proved. The static mechanical characteristics of the motor are built and the calculation of the droop of the mechanical characteristics for possible emergency modes is performed. © 2022 IEEE.Show more Item Correlation Theory of Casual Processes in Electrical Power Problems for Systems of Electric Transport (preprint)(IEEE, Lviv, 2015) Kostin, Nickolai A.; Mishchenko, Tatyana M.; Shumikhina, LyudmilaShow more ENG: A new method is proposed for determining the energy indices in electric transport systems, based on the correlation theory of random processes. According to this method, the components of apparent power and power factor are expressed through correlation functions and mathematical expectations of investigated traction voltages and currents. Numerical calculations of active, reactive and apparent power as well as the ratio of reactive power for a traction substation feeder show that the method possesses high accuracy: the error is less than 2%.Show more Item 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.Show more 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.Show more Item 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 DiabShow more 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.Show more Item Development of a Spectral Theory for Analysis of Non-Stationary Pulse Stochastic Electromagnetic Processes in Devices of Electric Transport Systems(National Technical University of Ukraine "Igor Sikorsky Kiev Polytechnic Institute", Kiev, 2019) Szeląg, Adam; Kostin, Mykola O.; Nikitenko, Anatolii; Mishchenko, Tetiana; Jefimowski, WłodzimierzShow more ENG: A spectral analysis of traction voltages and currents is a basis for estimation of electromagnetic compatibility level and quality of consumed power in electric transport systems. However, such an analysis is usually performed for steady-state modes and only under the condition that the time realization of voltages and currents, being deterministic for continuous quantities, have infinite length. De facto, the electric transport devices operate in non-stationary dynamic modes (starting up, coasting, acceleration, iregenerative braking, stopping, wheel spin, voltage surges, etc.). As a result, the voltage across the traction motors and the current flowing through them are noncontinuous pulsed stochastic processes. It is necessary to add that in emergency modes the voltage and current are short-term single pulses.The paper presents the spectral analysis of such random sequences of pulses as well as their fronts and decays, the concepts of actual and instantaneousspectra. The analytical expressions for amplitudes and the initial phases of k-th harmonics are obtained using the discrete Fourier transformation. The numerical calculations of the spectral composition of stochastic pulse processes of voltage and current were performed for the DE1 and VL8 electric locomotives (Ukraine) as well as for trams operating on the i routes of the city of Dnipro. The actual and instantaneous spectra, as well as the spectra of the full correlation functions and their “tails”, were determined for the electric traction voltages and currents.Show more Item Dispersive-Frequency Companding of Low-Frequency Finite Signals for Objects Remote Control(Национальный технический университет Украины "Киевский политехнический институт", Украина, 2014) Tunik, Vladimir F.Show more EN: There are noted specificities of known methods of frequency companding of radio signal by high frequency (HF) dispersive delay lines (DDL). It is proposed a principle of dispersive-frequency companding of low-frequency (LF) finite signals for remote control of physical objects and its realization system. It is shown that LF DDL of definite order can be both frequency compressor and frequency expander. The system of this principle realization at transmitting side contains LF DDL - frequency compressor and low-pass filter, and at transmitting side it contains LFDDLof the same order - frequency expander. © Allerton Press, Inc., 2014.Show more Item Electrodynamics of Electric Power Transmission and Losses in Devices of Electric Transport Systems(2018) Kostin, Mykola O.Show more ENG: For the first time, the "field" approach for explaining the processes of transmission and generation of electric power losses in devices of electric transport systems is described and theoretically substantiated on the basis of the theory of electromagnetic field. The results of the solution of the system of electromagnetic field equations show that it is energetically appropriate to design low-floor types of electric rolling stock. A qualitative view of electric power flows arriving through the air of the feeder zone from the traction substation and entering to the electric rolling stock through the roof and the front part of its body is presented. It is established that the main flow of energy enters through the roof porcelain insulator. At the same time, the electromagnetic waves partly penetrate into the metal surfaces of roof and frontal part of the body, and partially they are reflected from them creating losses of active power. The results of calculations of these losses, power factor and reactive power factor of the electric locomotive roof are shown. The relation between the standing waves, formed in the feeder zone, and the reactive power consumed by the electric rolling stock is established.Show more Item Electrodynamics of Power Losses in the Devices of Inter-Substation Zones of AC Electric Traction Systems(MDPI, Basel, Switzerland, 2022) Nikitenko, Anatolii V.; Kostin, Mykola O.; Mishchenko, Tatyana M.; Hoholyuk, OksanaShow more ENG: This article presents a new method for the estimation of active power losses based on a “field” approach, i.e., on the theory of the electromagnetic field and the theory of propagation of electromagnetic waves in a dielectric medium. Electromagnetic waves are assumed to transmit energy from the traction substation to electric rolling stock through the airspace of the inter-substation zone (i.e., not through the wires of the traction network) and meet electrically conductive surfaces on their way. The waves are partially reflected from the surfaces and partially penetrate them, thus creating thermal losses, the determination of which is the main task of this article. The analytical expressions for specific losses of active power are obtained by solving the system of Maxwell’s equations. Calculations of specific power losses in the catenary, rails, roofs, and bottoms of carriages and electric locomotives are performed. Power losses in carriages and electric locomotives are found to be at least 7%. A comparative assessment of the magnitude of total power losses of different types obtained by the “field” and “circuit” approaches is provided, which has established that “conditional” losses correspond to losses in rails, train carriages, and electric locomotives.Show more Item Electrodynamics of Reactive Power in the Space of Inter-Substation Zones of AC Electrified Railway Line(MDPI, 2021) Kostin, Mykola O.; Nikitenko, Anatolii V.; Mishchenko, Tatyana M.; Shumikhina, LyudmilaShow more ENG: In railway traction, the deﬁnition of “electromagnetic ﬁeld” is functionally connected to the concept of the reactive power consumed by the electric rolling stock, and characterized by the running and standing electromagnetic waves in the space of the inter-substation zones from the site of the AC traction system. Such a deﬁnition is established and theoretically justiﬁed by the theory of electromagnetic ﬁelds. This article uses the methodology of this theory, in particular, a method for power balance estimation in electromagnetic ﬁelds based on Maxwell’s equations, as well as methods for the analysis of running and standing electromagnetic waves based on the theory of reﬂection, propagation and transmission of plane harmonic waves. The research considers the regularities of standing electromagnetic waves in the space of inter-substation zones of electric traction systems, which occur due to the incomplete reﬂection of incident waves from the contact wire and metal parts of the roof surface and the frontal part of the body of the electric rolling stock. The ﬂow of electricity to the roof surface and the frontal part of the body of an electric locomotive is considered. The possibility of using existing methods to reduce wave reﬂections and thereby to effectively compensate for reactive power in the space of inter-substation zones is discussed.Show more Item Energy of Starting up to Speed of Dc Train(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Kostin, Mykola O.; Nikitenko, Anatolii V.Show more ENG: In the last 20 ... 25 years the volume of recuperated electric energy is less than 2% of the consumed by traction, while it is possible to return about 10 ... 15%. The main reason is unsatisfactory and inefficient usage of recuperated and transmitted energy to the power supply system. The paper proposes to solve this problem and induce the efficiency and the degree of recuperated energy of DC multiple unit trains by the usage of onboard supercapacitive storage system. The methods of the electric traction theory and the theory of pulse electrical engineering are used for the problem solving. The developed methodology allows to calculate the energy, which is required to starting up the multiple unit train EPL2T to some speed 10 ... 80 km/h after its stopping.Furthermore, the capacity of the on-board storage is calculated in two cases of storing recuperated energy. The novelty of the paper is the new method for estimating energy, which is required to starting up (after the stopping) the train to a certain speed. The analytical expression of the capacity of the on-board storage system was achieved and calculated for the previously estimated energy. For the first time it was found that the energy, which was saved by the on-board supercapacitive storage system, is sufficient to start up the train to some speed and reach the characteristic of full field of the traction motors. The proposed autonomous mode of recuperative braking allows, at first, to increase significantly the efficiency of energy recovery, and secondly, to reduce the weight and size parameters of on-board storage supercapacitors.Show more Item Energy Saving During Operation of Equipment with Non-Controlled Electric Drive in Locomotive Depot(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2016) Dubynets, Leonid V.; Marenych, Oksana L.; Baliichuk, Oleksii Yu.; Kortohus, A. S.Show more ENG: 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 kl ≤ 0.55 . 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 kl ≤ 0.7 , 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.Show more Item Experimental Investigation of Actual Stuation of using and Accounting of Recovered Energy of Regenerative Braking Mode at the DC Traction System(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Bondar, Oleh I.; Ustymenko, Dmytro V.; Kurylenko, Olena Ya.; Kedria, Mykhailo M.; Karzova, Oksana O.; Krasnov, Roman V.; Baliichuk, Oleksii Yu.Show more ENG: Abstract. 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.Show more Item Feasibility Study for Extending the Rolling Stock Component Life(Academic Society of Michal Baludansky, Kosice, 2019) Artemchuk, Viktor V.; Krasnov, Roman V.; Karasev, Oleksandr P.Show more ENG: The article deals with the problem of determining the rational extension of the railway rolling stock component life. It is noted that a key part of the repair development, including on railway transport, is an extended service life of the rolling stock components. Given that a significant proportion of the repair cost is spent for the replacement or repair of worn parts, there is a conclusion that component life must be extended to reduce further repair costs. However, unjustified increase in the service life of all components is not feasible, since the life of individual components may be greater than the life of the entire product. Obviously, it is not expedient to extend the life for all the details, but only that of the most responsible and (or) most worn out, which greatly affect the service life of the assembly or unit as a whole. That is, there is a need to match the life of the entire assembly and individual components. Therefore, in the presented work, theoretical research was carried out to solve the complex task of determining the rational life of rolling stock components taking into account the resource of assemblies and the rolling stock vehicle as a whole. When searching for rational parameters, the durability of components and the factors affecting their life were investigated and the possibilities of various restorative and strengthening technologies were evaluated. The developed approach is flexible and allows for consideration of technological limitations of production, financial constraints and the introduction of life limits for a specific component. Also the article covers the shortcomings of the presented methodology. At the same time it is should be noted that with the development of the diagnostic system, obtaining the necessary data will be less labour intensive and will require less time, and with the development of the necessary software, the accumulation and processing of statistics can be fully automated. In this paper, it is assumed that the presented methodology will make it more attractive to use renewable technologies, save considerable resources and find the necessary restorative or strengthening technology that will bring the life of different components closer to the life of the assembly or mechanism as a whole.Show more Item Fryze Reactive Power in Electric Transport Systems with Stochastic Voltages and Currents(2020) Kostin, Mykola O.; Mishchenko, Tetiana; Hoholyuk, OksanaShow more ENG: The paper presents the theoretical foundations of reactive power and additional power losses in a direct current electric transport system. Numerical calculations of inactive power and losses in the circuits of electric DC locomotives and trams have been carried out. Discrepancy between the sign of the instantaneous power and the presence of exchange processes in non-linear circuits of electric transport systems with stochastic voltages and currents is discussed.Show more Item Fryze Reactive Power of Trams in Eeffective Stochastic Rrecuperation Processes(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Bondar, Oleh I.; Kostin, Mykola O.; Mukha, Andrei; Sheikina, Olha H.; Levytska, Svitlana І.Show more ENG: Abstract. Urban electric transport system, particularly tram systems, is not a direct current system not only in traction mode but in regenerative modes as both voltage on a collector and regenerative current are stochastic abruptly variable processes. The above- mentioned facts determine availability of Fryze’s reactive power in this system that flows from a railway substation to trams, leads to incidental losses of energy and significantly reduces its quality. So evaluation of power effectiveness of the system in electrical trams operation is impossible without determining the level of reactive power in this system. We have analytical expression of reactive power by Fryze. Numerical calculations for trams type T3D and T4D in regenerative braking modes are done. Probabilistic statistical data processing operation of reactive power expressions is done. It is determined that reactive power changes in the limit of 10…100 kilo-volt ampere reactive with mathematical expectation – 37,0 kilo-volt ampere reactive. Statistical allocation of random power values are different. Numerical calculations of incidental losses, energy of recuperation are done and they range supplementary – 20% from total losses. It is stated that coefficient of reactive power of system route of trams is exceeding permissible value 0,25.Show more Item The Impact of Connecting a Wind Power Plant on Emergency Modes of a Traction Substation of an AC Traction System(Springer, Cham, 2022) Kachan, Yurii; Kuznetsov, Vitaliy V.; Bondar, Oleh I.Show more ENG: Among the countries of South-Eastern Europe, Ukraine has the greatest technical potential for the implementation of renewable energy sources, and the main part of it is wind power engineering. The traction power supply system of the railways in Ukraine can become an important transiter and consumer of electricity generated by wind power plants. At the same time, the task of ensuring traffic safety and uninterrupted power supply of traction loads requires a preliminary study of the influence of the connected wind power plant capacity on the growing short-circuit currents in the distributive units of the traction substation to which the specified connection is planned. This paper proposes a way to implement such prediction based on a systematic approach, in which a traction substation and an integrated wind power plant are considered as a single electrical-engineering complex, the sources of which work to power the short-circuit point. In previously published studies, the authors usually consider the processes in renewable energy sources and in the traction power supply system separately, without taking into account the mutual influence. The analysis of processes in the short-circuit mode is proposed to perform according to the equivalent circuits for the specified electrical-engineering complex developed by the authors with various possible options for connecting a wind power plant using mathematical modeling with proven methods of theoretical electrical engineering. The peculiarity of the study presented in this paper is also the use of the multiplication factor of the short-circuit current as a criterion for assessing the impact of the power of the connected wind power plant on the short-circuit currents of the traction substation. In our opinion, the coefficient applied by us more clearly characterizes the specified influence in comparison with operating values or complex sizes of short-circuit currents.Show more Item Improvement of Energy Indicators of Conventional Electric Driving Asynchronous Motors of Non-Standard Technological Equipment at the Enterprises for Repair of Railway Rolling Stock Through the use of Energy-Saving Motors(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Bondar, Oleh I.; Baliichuk, Oleksii Yu.; Karzova, Oksana O.; Krasnov, Roman V.; Marenych, Oksana L.; Ustimenko, DmytroShow more ENG: Abstract. 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.Show more Item Inactive Power in Electric-Traction DC Transport Systems(Revijo izdaja Elektrotehniška zveza Slovenije, 2022) Kostin, Mykola O.; Mishchenko, Tetiana; Hoholyuk, OksanaShow more ENG: The paper presents a theoretical background to determine the inactive power consumption features, i.e. the reactive power according to S. Fryze approach of the electric transport systems. Traction electric circuits of transport facilities of electric locomotives, feeder traction substations and city trams used in Ukraine demonstrate three features of the reactive power. According to the classical method, the inequality between the active and total power indicates the presence of the reactive power. The second feature is the time variation of an instantaneous impedance or instantaneous conductivity. The third is the inequality between the instantaneous reactive power to zero and the nature of its sign throughout the time of the electric power system consumption. The reactive power consumption gives rise to considerable additional power losses in the electric traction transport systems.Show more Item Influence of Contactor Contact Pressure in Power Circuits of Electric Stock on their Plastic Deformation and Fusing(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Baliichuk, Oleksii Yu.; Dubynets, Leonid V.; Marenych, Oksana L.; Ustymenko, Dmytro V.Show more ENG: Purpose. The work is aimed at conducting the study to obtain the results that will quantify the influence of contactor contact pressure in power circuits of electric stock on the highest current value d I , that does not cause plastic deformation of contacts; and on the current value fs I – incipient fusion of contacts taking into account the operation conditions. Therefore, such a study targeted to establish the contact fusing causes is relevant. Methodology. The paper proposes an engineering method for determining the currents d I and fs I , taking into account the value of contact pressure, electrodynamic forces of contact repulsion e.d.r F , as well as the pressure influence on the values of such forces. Findings. Taking the contactors 1SVAD8 (locomotive ChS8) and 7SP1 (locomotive ChS4) as an example, the authors conducted the calculations and found that the peak pressure force increases the currents d I and fs I for these contactors by 11.8%; 15.5%; 11.8%; and 15.4% respectively (compared with the specified currents at the minimum pressure force). Influenced by e.d.r F the pressure force of contacts for 1SVAD8 contactor decreased by 13.8…31.8%, and for 7SP1contactor the value e.d.r F may be greater than the pressure force. This can lead to spontaneous shutdown of the closed contactor that is not provided by the control circuit. Ensuring during operation the maximum allowable pressure force of the contacts c F slightly affects the value e.d.r F, compared with the case when c F has the minimum permissible value (in event of a fault in the heating circuit e.d.r F for contactors 1SVAD8 and 7SP1 is reduced by only 2.45% and 2.59% respectively). Originality. The authors for the first time presented a quantitative assessment of influence of contactor contact pressure in power circuits of electric stock on their plastic deformation and fusing using the proposed engineering method. Practical value. The results obtained during the research allow solving the problem for developing measures aimed to improve the reliability of the heating circuits of electric locomotives ChS8 and ChS4. The proposed method of determining d I and fs I can be used to quantify the influence of pressure of the main electric contacts mounted in power circuits of electric stock of all series, if during the operation there are cases of plastic deformation, fusing, welding of such contacts, in order to improve the reliability of power circuits.Show more