Browsing by Author "Kuznetsov, Valeriy"
Now showing 1 - 20 of 32
Results Per Page
Sort Options
Item Analysis of the Neutral Grounding Modes Influence on the Reliability Characteristics of Local Systems with Renewable Energy Sources(Polskie Towarzystwo Diagnostyki Technicznej, Warszawa, 2021) Ostapchuk, Oleksandr; Kruczek, Włodzimierz; Kuznetsov, Valeriy; Kuznetsov, Vitaliy; Tsyplenkov, DmytroENG: When comparing the performance indicators of electrical networks with different types of neutral grounding, along with the fulfilment of the requirement to ensure reliability of power supply to consumers, serious attention is drawn to the main network parameters influencing the performance of power supply systems. Analysis of research and its results, reported above, on the influence of the neutral ground of power networks on the reliability and electrical safety conditions of the power supply systems as a whole, on the damage of distribution networks and electrical equipment as well as on the working capacity of relay protection devices, provides an opportunity to estimate each specific operation mode of the neutral and to develop recommendations aimed at strengthening the positive indicators of the corresponding modes. Other things being equal, reliability of power supply to electrical receivers or reliability of distribution networks is mainly determined by the damage to network elements and the performance of relay protection devices. The degree of influence of these factors on the reliability of distribution networks depends on the neutral mode, which in turn determines the level of overvoltages and the nature of transient processes at ground failure.Item Automatied Workstation for Calculating Rational Mode of Traction Power Supply Systems(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Kuznetsov, ValeriyEN: Improving the competitiveness and efficiency of railway transport of Ukraine is impossible without solving a number of priority issues, including: providing a rational railway technology taking into account energetic, economic and environmental criteria, infrastructure development for high-speed motion, improving consumption energy planning, the implementation of effective management at all levels of the production cycle. This list very important problem is energy saving in power supply traction systems. This problem is complex, multi-level and multi-factor in nature. The definition of rational modes of traction power supply DC systems has previously been performed without taking into account the realities of our time, when there is a market economy, there are different options for electricity payment (by flat-rate tariffs, differentiated tariffs or wholesale prices for electricity). Now, the energy component in the transportation tariff has reached 20%, and taking into account global trends will continue to rise. When making decisions in firstly we need to take into account not only technical indicators, but also economic (cost of electricity consumed). The paper presents the principles of rational modes of the power supply systems. This make a basis for creation a monitoring system for ensuring the rational modes, which could for each time point evaluate the power supply system mode and propose the measures to ensure the most profitable mode. It's done the description of the specialized software that allows you to define rational modes of traction power supply system. The discussed program uses a genetic algorithm to determine the rational modes. This article contains screenshots of developed software.Item Badanie Skali Zmienności Obciążeń Wybranej Tramwajowej Podstacji Trakcyjnej na Podstawie Rzeczywistych Wyników Pomiarowych dla Spójnego Okresu Czasowego Obejmującego Szesnaście Tygodni(Politechniki Krakowskiej im. Tadeusza Kościuszki, Kraków, Polska, 2015) Drapik, Slavomir; Kuznetsov, Valeriy; Markowski, Paweł; Prusak, Janusz; Woszczyna, BartoszPL: Zmienność obciążeń trakcyjnych powoduje, że projektanci muszą dobierać moc zespołów prostownikowych dla podstacji trakcyjnych DC ze znacznym przewymiarowaniem. W artykule, na podstawie wyników pomiarowych eksploatowanej tramwajowej podstacji trakcyjnej, przedstawiono skalę przewymiarowania mocy zespołów prostownikowych tej podstacji. Stwierdzono występowanie znacznych odcinków czasowych, w których moce zespołów prostownikowych nie są wykorzystywane. Obliczono współczynniki przeciążeń chwilowych dla różnych odcinków czasowych, następnie przeprowadzono ich analizę statystyczną. Zwrócono uwagę na rozwiązanie techniczne mogące w przyszłości ograniczyć straty energii w podstacjach trakcyjnych DC.Item Comprehensive Study of the Microclimate Parameters in the Residential Building(Sciendo, Poland, 2021) Yurchenko, Yevhen; Kuznetsov, Valeriy; Radkevich, Anatolij V.; Koval, Olena; Skrzyniarz, Marek; Kruczek, Włodzimierz; Mike, Kamil; Mroczkowski, ŁukaszENG: The relevance of the research lies in the development of the current question about the influence of microclimate quality on the efficiency of residential units. The aim of the study is to examine how the microclimate parameters affect the efficiency of residential buildings. Findings. The results obtained are essential for the design of energyefficient and comfortable residential buildings. The scientific novelty and practical importance of research resides in the thorough study of microclimate in low-rise residential buildings. Microclimate deviation charts for residential buildings have been produced.Item The Concept of a Hybrid Traction Power Supply System(Les Ulis: EDP Sciences-Web of Conferences, France, 2019) Sychenko, Viktor G.; Kuznetsov, Valeriy; Kosariev, Yevhen; Bekh, Petro V.; Sayenko, Yuriy; Styslo, Bohdan O.; Pavlichenko, Mihail; Vasilev, Ihor; Pulin, Mykola M.ENG: Abstract. The growing shortage of energy resources to provide heavy traffic and high-speed traffic necessitates the development of a new power supply scheme for a traction network using sources of distributed generation of electric energy. Application of asymmetric distributed traction power system with the use of distributed generation allows to increase electric energy efficiency of the feed system of rolling stock, reduce its material capacity and increase the reliability of the functioning of the railway system as a whole. The proposed structure of the hybrid electric traction system involves the creation of a new paradigm aimed at ensuring high demands on the voltage and specific power in the traction network, which will allow to improve the quality and safety of the transportation process when increasing the energy performance indicators. This paradigm will allow to form a new philosophy of building traction power systems. The key elements of this philosophy are decentralization of generation and consumption of electric energy, the use of intelligent electric equipment, distributed power supply management in a single information space of the energy process during transportation. The peculiarity of the proposed work is the optimal combination of technological processes of transmission, consumption of electric energy and transportation, taking into account the specific conditions of functioning of the electrified section: points of connection of power sources and their type, profile of the track, schedule of trains, types of rolling stock and equipment. Conceptually, the hybrid traction power system is an electric hub, in which the inputs are generating points, and the output is the power supply system of the rolling stock. The internal structure of the electric power objects of the hub is determined by the type of transformation and accumulation of electric energy and ways of managing these objects in real time.Item Development of an Approach to Ensure Stability of the Traction Direct Current System(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Sychenko, Viktor G.; Kuznetsov, Valeriy; Kosariev, Yevhen M.; Hubskyi, Petro V.; Belozyorov, Vasiliy Ye.; Zaytsev, Vadym G.; Pulin, Mykola M.EN: The result of applying the quantitative approach to the calculation of static stability of the traction power system helped us establish that when a train runs along an actual section there emerge zones with lack of stability in terms of voltage. Exact solution to the task of evaluating the stability is extremely difficult because of the need to compute the nonlinear dependences determining the modes of operation of the traction power system and electric rolling stock. In this work, we constructed a system of four autonomous nonlinear differential equations based on experimental data that simulate the behavior of current and voltage in the contact network. We also calculated stability regions for voltage regulators in the traction network, which stabilize voltage at pantographs of electric rolling stock. The obtained stability regions of voltage regulators made it possible to estimate resource of stability and to find the most robust regulators out of those constructed. The study revealed that the non-linear regulator has better robust properties than the linear one. In this case, stability of the linear regulator is very narrow ‒ Δk=0.000004, which is an order of magnitude lower than for the non-linear regulator. When applying the non-linear regulator, voltage in the contact network stabilizes 3 times faster regardless of the place of its location. Application of the devised approach would make it possible to calculate the stability regions for various schematics of the traction network in the implementation of high-speed motion and to narrow the range of voltage fluctuations. The developed dynamic model of power consumption processes, as well as the voltage regulator, could be used when constructing an intelligent, adaptive traction power system for high-speed motion.Item Development of Mathematical Models of Energy Conversion Processes in an Induction Motor Supplied from an Autonomous Induction Generator with Parametric non-Symmetry(НВП ПП «Технологічний Центр», Харьків, 2021) Chenchevoi, Volodymyr; Kuznetsov, Valeriy; Kuznetsov, Vitalii; Zachepa, Iurii; Chencheva, Olga; Chornyi, Oleksii; Kovzel, Maksim; Kovalenko, Viktor; Babyak, Mykola O.; Levchenko, SerhiiENG: The paper presents studies of the system “induction generator-induction motor” with parametric asymmetry on a mathematical model to determine the quality of generated electricity in load operating modes. A mathematical model of the “induction generator-induction motor” system has been developed taking into account losses in steel and parametric asymmetry. The analysis of the transient characteristics of an induction generator when a motor load is connected in symmetrical and asymmetrical modes of operation is carried out. The results of changes in the main characteristics of an induction motor at various degrees of parametric asymmetry in the generator are presented. The quality of the generated electricity was analyzed based on the calculations of the unbalance coefficients for each of the operating modes. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an induction motor from an autonomous energy source based on an induction generator. On a thermal mathematical model, the study of the effect of the output voltage asymmetry on the heating of the connected induction motor was carried out. It is shown that the asymmetry of the output voltage of an induction generator reaches 3–10 % and causes overheating of the windings in excess of the permissible values. A regression model has been developed for studying the operating conditions of an induction motor when powered by an induction generator with an asymmetry of the stator windings. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of induction machines, in which they will not overheat above the maximum permissible temperature values of the corresponding insulation classes.Item Development of the System of Initial Excitation of the Autonomous Induction Generator(Springer, Singapore, 2022) Chenchevoi, Volodymyr; Kuznetsov, Valeriy; Zachepa, Iurii; Chornyi, Oleksii; Chencheva, Olga; Kuznetsov, Vitaliy V.; Yatsiuk, Rostyslav; Luhova, OlhaENG: The article defines the conditions of self-excitation of an inductive generator with capacitor excitation as part of an autonomous power source. Recommendations for the design of an autonomous power source based on an asynchronous machine in terms of the implementation of self-excitation conditions and optimal operating modes are formulated. A simulation model of an autonomous inductive generator and a solar battery for the analysis of transient, static and dynamic modes of operation has been developed. The conducted theoretical studies of capacitive self-excitation of inductive machines have created a good basis for solving problems related to the practical use of autonomous sources based on an inductive generator.Item Efficiency of Energy Storage Control in the Electric Transport Systems(Politechnika Warszawska; Instytut Transportu, Poland, 2022) Sablin, Oleg I.; Bosyi, Dmytro O.; Kuznetsov, Valeriy; Lewczuk, K.; Kebal, Ivan; Myamlin, Sergiy S.ENG: The problems of storage and supplying the energy, together with reducing energy intensity for transport, are now crucial for developing sustainable and reliable transport systems. The energy network must be gradually adapted to new loads and power consumption patterns, especially in railways. The article aims to develop the simulation model to investigate the energy storage systems in its use in the electric transport infrastructure. The authors review selected technical solutions for electric energy storage in transport. The theoretical aspects of energy exchange in the energy storage systems were presented as a base for a continuous simulation model of electric transport power supply. In the non-periodic random voltage input applied to the storage unit, it is proposed to use the calculation method based on the Duamel integral to analyze its charge-discharge processes. The resistance functions were applied to analyze the traction power supply mode with variable in time and space by active loads. The simulation showed that the direct connection of the unit to the traction network significantly reduces the traction energy consumption.Item The Efficiency of Using Artificial Feedforward Neural Networks with a Single Hidden Layer of Eight Neurons for the Analysis of Overload Conditions of Selected Tramway Traction Substations(Uniwersytet Jagielloński, Kraków, 2018) Dudzik, Marek; Prusak, Janusz; Drapik, Sławomir; Kuznetsov, ValeriyEN: This paper presents further results of research on the load variability of rectifier units for the selected tram traction substation. Actual measurements were used in the performed analysis. This time, the analysis was focused on the characteristics of maximum loads and overloads for time periods of five minutes and sixty minutes, for a number of selected cases. The second part of the article discusses the effectiveness of the use of artificial neural networks of the feedforward type with one hidden layer with eight neurons to analyse the overloads of the traction substation over a longer time scale. The obtained positive results indicate that this type of research should be continued, using different variants of artificial neural networks.Item Energy Characteristics of the DC Distributed Power Supply Systems(University of Žilina, Slovakia, 2021) Sychenko, Viktor G.; Kuznetsov, Valeriy; Rojek, Artur; Hubskyi, Petro V.; Kosariev, Yevhen M.EN: Currently the circuit technology of the DC traction power supply system cannot provide the necessary requirements for introduction of high-speed traffic. Numbers of measures and tools have been developed to improve the traction lines that no longer meet current requirements. One of the most promising means for strengthening the traction DC lines is transition to the distributed power supply of the rolling stock. In this article, a comparative analysis was carried out of energy indicators of the classic centralized power system and distributed power systems with use of one aggregate traction substation and with use of the solar generators. That comparative analysis of these systems was performed on a simulation model with the same parameters of the traction line and rolling stock.Item Energy Efficient Distributed DC Traction Power Supply System(Kaunas University of Technology, Lithuania, 2019) Bialon, А.; Kuznetsov, Valeriy; Sychenko, Viktor H.; Hubskyi, Petro V.EN: Abstract. The classical systems of centralized power supply do not allow to provide the necessary conditions for the introduction of high-speed traffic on existing lines. Voltage values both on the buses of the traction substation and in the traction lines have a significant range of oscillations. Having a significant reserve of installed aggregate power at traction substations in Ukraine, there are no means of voltage modes regulation in the traction lines. Existing foreign and Ukrainian means for increasing of the energy efficiency of ОС traction power supply systems require significant capital investments and do not take into account the peculiarities of the organization of high-speed traffic. Therefore, it is ology of distributed power supply with the maximum use of existing infrastructure, taking into account the features of the high-speed trains load.Item Energy-Efficient and Cost-Effective Methods of Driving Trains under the Conditions of Development of the Electricity Market(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Pshynko, Alexander N.; Afanasov, Andriy M.; Kuznetsov, Valeriy; Skalozub, Vladyslav V.; Arpul, Serhii V.; Ivanov, Alexander P.ENG: Abstract. The article for the first time considers the possibilities for the organization of cost-effective rail transportation on electrified section in terms of the functioning of the Ukrainian balancing electricity market. It is formulated the complex task of choosing effective mechanisms of purchase and sale on the electricity market on the basis of contracts for the implementation of markets "for the day ahead", as well as for the appointment of parameters and tariffs of the intraday market. The authors presented the models and results of calculations of optimum modes of trains’ driving, which are calculated for various criteria of efficiency taking into account the cost of the consumed active and reactive electric energy. The technique of tariff formation for purchase of electricity on the balancing market was proposed.Item Improvement of the Regenerating Energy Accounting System on the Direct Current Railways(Polska Akademia Nauk, Warszawa, Poland, 2015) Kuznetsov, Valeriy; Sablin, Oleg I.; Chornaya, Alenka V.EN: Purpose. Monitoring of current state of quantitative indices of regenerative energy in the suburban movement, the analysis of the factors influencing its volumes and improvement the principles of the train regenerative energy accounting on the basis of it. Relevance. Development of effective measures of increase the regeneration efficiency of the electric power in system of electric traction demands comprehensive completeness of information on quantitative indices of regeneration energy volumes at all possible levels of its analysis, in particular on the corresponding sections of RS movement that will allow to establish the influence on the level of regeneration of various factors, such as parameters of traction power supply and the organization of train service. As the existing system of the regenerative energy accounting does not allow to consider the specified factors, development of the principles for increasing the efficiency of the analysis of volumes of return energy to a contact line during regenerative braking on DC rolling stock is the actual direction of researches. Collective monitoring of regeneration energy volumes by specialists of locomotive service, power supply and traffic operating departments will be essentially new approach to definition of real factors and taking effective decisions for increasing of using of regenerative energy. Scientific novelty. It’s offered to consider the influence on quantitative indices of regenerative energy the parameters of traction power supply and the organization (sizes) of traffic service on sections. Practical importance. Increasing the efficiency of the regeneration energy accounting is an important element in drawing up the balance of energy for electric traction system, development of the effective methods for improvement of the conditions of regeneration in it and in estimation of its power indicators in general.Item Improving the Efficiency of the Heating System for Public Buildings Infrastructure in the Context of DNURT(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Pshinko, Oleksandr M.; Kuznetsov, Valeriy; Yatsenko, Dmytro K.; Gabrіnets, Volodymyr O.EN: Purpose. The paper analyses the possibility and terms of increasing the efficiency of heating and ventilation systems of public buildings at the present stage of development and the specific climatic conditions of Ukraine. The main purpose is to develop specific measures for public buildings, which will lead to a significant reduction in energy costs for heating and air conditioning system. The example is similar system of DNURT compact campus, which is heated with its own autonomous boiler that uses natural gas. Methodology. The statistical heat loss analysis for the last 5 years allows defining the types and calculating the heat loss values for specific conditions. These losses are compared with those in the world practice and based on the comparison and analysis of the current system there are offered the ways to reduce the heat loss values through the use of various technical and organizational methods. The paper also proposes involvement for this purpose of secondary and alternative energy sources. The secondary energy resources include the heat that is emitted by people and that coming out with the air during ventilation of buildings. The renewable sources include solar and geothermal energy. To enhance the heat transfer medium temperature capacity it is proposed to use the heat pumps. Findings. The maximum possible use of the proposed measures and implementation of rational schematic and engineering solutions for heat and hot water supply systems cam reduce the energy loss for heating and hot water by 30-35%. Originality. The paper for the first time proposed the use of new integrated approaches to maintain the desired heat balance in the winter period, as well as the new schematic solutions for heating and ventilation systems, both in winter and in summer, based on the use of heat pumps and secondary energy resources. Practical value. The introduction of the proposed schematic solutions and approaches demand relatively small capital investments and do not require significant reconstruction of already installed systems.Item Integrated Use of Photovoltaic and Wind Power Plants in Power Supply Systems(Springer, Singapore, 2022) Ostapchuk, Oleksandr; Kuznetsov, Valeriy; Bydko, Maryna; Kuznetsov, Vitaliy V.; Kuznetsova, YevheniiaENG: The use of energy from only one type of renewable energy source (e.g., solar and wind generation) leads to a significant increase in the cost of electricity supply due to the need to install a backup power source (energy storage system or power system). This phenomenon is caused by the significant dependence of these sources on weather conditions. The wind speed is less than 4 m/s for a long time in summer, and solar energy is not available at all in dark day periods, which in December can last up to 16 h. Accordingly, the effective use of such systems is possible only if constructing a complex application of several sources of different nature (solar and wind generation). This measure allows increasing their energy efficiency by 30–50%. The combined use of these types of distributed generation is accompanied by the equalization of the daily energy intake due to the spread of the annual maximums of energy intake, but the daily fluctuations remain pretty significant. As a result of the conducted researches, it is established that when using the share of solar energy at the level 0.4… 0.55 of the total amount, the shortest period of energy deficit (at the level of 8 days per year) is observed. At other ratios between the shares of solar and wind energy, the period of energy deficit will increase. In case of increased requirements for providing responsible consumers with electricity, it is advisable to use systems with buffer electricity storage. The developed mathematical models allow calculating the equipment parameters used in the construction of efficient power supply systems.Item Lyapunov Function in the Hyper-Complex Phase Space(Springer, Singapore, 2022) Voliansky, Roman; Volianska, Nina; Kuznetsov, Valeriy; Sadovoi, Aleksandr; Kuznetsov, Vitaliy V.; Kuznetsova, Yevheniia; Ostapchuk, OleksandrENG: The paper deals with the development of background for defining Lyapunov functions for a wide range of linear dynamical objects. This background is based on assuming that the Lyapunov function is redundant energy in the considered object, and this energy is dissipated only during controlled motion. We assume the full derivative of the Lyapunov function for an autonomous motion of the control objects equals zero, and we use its summands to define linear algebraic equations. The solution of these equations allows us to find unknown terms of the Lyapunov function. The use of these terms, while the Lyapunov equation is being written down, shows that the left-hand expression in the Lyapunov equation is equal to the zero matrix. Thus, we avoid subjective assuming of quadratic form terms in the right-hand of the Lyapunov equation. We extend the proposed approach to the class dynamical system with uncertainty. This extension is performed by using interval methods, which allow defining object motions for minimal and maximal values of parameters. We show that for the control object, which parameters are not exactly known, one should consider two equations of object motions, which correspond to its trajectories on the boundaries of the intervals. Lyapunov functions are defined for these boundary trajectories. Since such an approach increases the number of the considered equations, we offer to decrease them by using hyper-complex numbers while object equations are written down.Item Mathematical Models of Effective Topology of Computer Networks for Electric Power Supply Control on Railway Transport(University of Žilina, Slovakia, 2022) Stasiuk, Oleksandr; Kuznetsov, Valeriy; Zubok, Vitalii; Goncharova, Lidiya; Muntian, Antonina O.ENG: The paper is devoted to analysis of modern directions of innovation-investment formation of intelligent computer networks that control the fast-moving technological processes of electricity supply. It is based on the conclusion that the problem of increasing the productivity of information exchange between information resources and consumers is dominant. A method for increasing the efficiency of information exchange is proposed as a search for the rational location of a new node and the organization of such a set of its connections among the whole set of nodes of the computer network, which provides a minimum average topological distance. Mathematical models of effective topological organization of connections in computer network of power consumption control at the level of traction substations, electric power distances and the railway in general are proposed.Item The Method for Increasing the Efficiency of Equipment's Maintenance in Railway Traction Power Supply Systems(Warsaw University of Technology, Poland, 2018) Matusevych, Oleksandr O.; Kuznetsov, Valeriy; Sychenko, Viktor G.EN: Purpose. To develop the method for increasing the efficiency of the equipment’s maintenance and repair system, ensuring necessary level of operational reliability of the equipment, safety and reliability of the electric equipment with minimal expenses on operation. Relevance. Aging of the power equipment in railway power supply systems sharply raised a need for assessment of its states and degree of risk for operation outside rated service life. In critical conditions of technological processes and operational modes of the railways it is necessary to increase the equipment’s operational reliability. The scheduled maintenance and repair system whose main technical and economic criterion is the minimum of equipment’s downtimes on the basis of a rigid regulation of repair cycles, in the conditions of market regulations in the field of repair in many cases does not provide the optimal decisions due to insufficient financing. The solution of this problem is possible by improvement of the maintenance and repair system. Under these conditions the main direction for supporting the operational reliability of power electric equipment on TS is a development of the modern methods based on individual supervision over real changes of technical condition of power equipment. Scientific novelty. In this article the authors proposed an integrated approach, on the basis of which can be developed the effective maintenance and repair system for traction power supply systems. Proposed approach allowed to react quickly to changes of service conditions on traction substations, to control the technical condition of power electric equipment under the conditions of uncertainty, to establish interrelation between quality of service and operational reliability of the equipment, to choose a service strategy on traction substations. Practical importance. The validity of the developed method was confirmed by the results of calculations and practically by choosing the optimal maintenance's option for transformer TDTN-25000/150-70 U1 (ТДТН-25000/150-70 У1) on traction power supply substation.Item Modeling the Quality of Current Collection Under the Conditions of a Growing Speed of Rolling Stock(Kaunas University of Technology, 2020) Kaniewski, M.; Kuznetsov, Valeriy; Hubskyi, Peter V.; Sychenko, Viktor G.; Antonov, Andrii V.EN: The use of high-speed electric rolling stock necessitates increased requirements for the reliability of its operation. Particular attention should be paid to the interaction of the contact line with current collectors. An important area is the development of tools for modeling the interaction of catenary with current collectors. At present, in some sections of railways, there is a need to increase the speed of trains and adapt the requirements for the design of the contact lines, which allow to the owner of the infrastructure to achieve the correct parameters for dynamic interaction on the pantograph-contact line interface in the point of view of the requirements of Energy TSI. In this work the authors discussed the problem of the equivalenting the contact line during the simulation