Кафедра електричної інженерії (ДМетІ)

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ENG: Department of Electrical Engineering (Dnipro Metallurgical Institute, DMetI)

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Adaptation of a Predicate Model in Control Problems of Nonstationary Static Objects
(Український державний університет науки і технологій, ННІ «Дніпровський металургійний інститут», ІВК ≪Системні технології≫, Дніпро, 2025) Tryputen, Mykola; Kuznetsov, Vitalii V.; Verovkin, Oleksandr; Ivliev, Vitalii
ENG: When controlling static objects at the optimization level, pattern recognition methods are used that allow partitioning the factor space into elementary subdomains in the form of n-dimensional hyperparallelepipeds. One of the main elements of the control structure for this approach to control is the adaptation algorithm, that makes it possible to refine the description of a static object under nonstationarity conditions. Repeated use of the adaptation algorithm to refine the model leads to an unjustified complication of its logical structure and the accumulation of information that has lost its relevance. The paper proposes a method for minimizing the description of images of technological situations, that makes it possible to overcome the indicated disadvantages. The method is based on the property of invariance of the number of parameters defining the hyperparallelepiped to the size of the described area in the factor space. This made it possible to identify significant boundary sub-areas in the description of the image of technological situations and, by their subsequent combination in the direction of the feature axes, to select a description with a minimum number of sub-areas. When performing these operations, “outdated” information is removed and the logical structure of a static control object is simplified as much as possible. The paper shows the possibility of implementing an algorithm for minimizing the description of images on the basis of α-algebra, that makes it possible to integrate its control structures using relational data models. The effectiveness of the proposed algorithm is confirmed by computational experiments in the control of the process of lump crushing for the conditions of a mining and processing plant.
Adaptation of a Predicate Model in Control Problems of Nonstationary Static Objects
(Український державний університет науки і технологій, ННІ ≪Дніпровський металургійний інститут≫, ІВК ≪Системні технології≫, Дніпро, 2025) Tryputen, Mykola; Kuznetsov, Vitalii V.; Yvanova Lyudmyla Kh.
ENG: When controlling static objects at the optimization level, pattern recognition methods are used that allow partitioning the factor space into elementary subdomains in the form of n-dimensional hyperparallelepipeds. One of the main elements of the control structure for this approach to control is the adaptation algorithm, that makes it possible to refine the description of a static object under nonstationarity conditions. Repeated use of the adaptation algorithm to refine the model leads to an unjustified complication of its logical structure and the accumulation of information that has lost its relevance. The paper proposes a method for minimizing the description of images of technological situations, that makes it possible to overcome the indicated disadvantages. The method is based on the property of invariance of the number of parameters defining the hyperparallelepiped to the size of the described area in the factor space. This made it possible to identify significant boundary sub-areas in the description of the image of technological situations and, by their subsequent combination in the direction of the feature axes, to select a description with a minimum number of sub-areas. When performing these operations, “outdated” information is removed and the logical structure of a static control object is simplified as much as possible. The paper shows the possibility of implementing an algorithm for minimizing the description of images on the basis of α-algebra, that makes it possible to integrate its control structures using relational data models. The effectiveness of the proposed algorithm is confirmed by computational experiments in the control of the process of lump crushing for the conditions of a mining and processing plant.
Advanced Space Vector Modulation with “Fractional” Power Cells
(Elsevier B.V., 2025) Busher, Victor; Shestaka, Anatoliy; Melnikova, Lubov; Kuznetsov, Vitaliy V.; Mykhailenko, Oleksii; Kovalenko, Viktor; Kutyk, Viktor; Osadchyi, Dmytro; Osypenko, Iryna O.; Abdel Gawad, Samer
ENG: The paper develops a model and studies various operating modes of a 5-phase multi-level cascade inverter as part of high-voltage powerful variable-frequency drives (VFD) with the most typical fan load for this type of electric drives. The aim of the work is to test the efficiency of the balanced spatial-vector pulse-width modulation method in a multi-phase high-voltage multi-level inverter in emergency modes by simulating the electric drive in the MATLAB/SIMULINK/Simscape Electrical environment. The paper studies the features of using the balanced spatial-vector pulse-width modulation method in a five-phase frequency converter in normal and emergency modes and, especially, the differences from a three-phase inverter with a similar control principle. The model with a 5-phase synchronous motor from the MATLAB ac8_example.slx database is taken as a basis, which allows us to consider the simulation results reliable. The rules for calculating phase voltages in normal and emergency modes are formulated and the corresponding blocks of the inverter control system model are prepared - a block for calculating basic vectors and a block of spatial vector pulse-width modulation (PWM). The output signals of this block are used for further processing in the modules for controlling power cells with 2- or 3-level PWM. Such a model for a 5-phase electric drive has been built for the first time, which is a scientific novelty of the work. Calculations of transient processes showed the absence of any oscillations, shocks when the system switches from normal to emergency mode and vice versa. That is, the proposed method of balanced spatial vector modulation preserves the symmetry of electromagnetic fields in the engine when individual H-bridges are damaged. It is shown that in normal mode, a 5-phase inverter using the spatial vector modulation method allows increasing the utilization factor of voltage sources by 23.1%. When individual power cells in phases fail, the utilization factor may decrease, but in any case it remains greater than 1. The method ensures compensation for emergency damage even in the event of a short circuit of one or two inverter phases. This significantly increases the service life of the electric drive, which is especially important in critical mechanisms and technological processes, where such complex inverters are actually used. The study found that when using the proposed method in a 5-phase VFD, unlike a 3-phase one, the current balance in the load is disrupted, which leads to increased heating of individual phases of both the motor and the power section of the inverter. The second point of scientific novelty of the work is that in order to reduce this negative effect, it is proposed to improve the algorithm for calculating the output coordinates of the regulator by using the so-called “fractional” power cells with a voltage that is not a multiple of their rated voltage. This leads to a smooth change in phase shifts and asymmetry when individual H-bridges and even one or two phases are damaged. This, in turn, reduces the current imbalance and the corresponding overheating from 2...3 to 12...15%, which gives confidence in the efficiency of using this improvement. It is also important to note that such a change in the control algorithm does not require any changes in the circuit and does not increase the requirements for the computing power of the processors used.
Analysis and Design of the Interval Optimal Electromechanical Systems
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2025) Voliansky, Roman; Kuznetsov, Vitaliy V.; Metelenko, Natalia; Kovalenko, Viktor; Spirintsev, Dmytro V.; Babyak, Mykola O.; Tryputen, Mykola; Tkalenko, Oleksandr; Halushko, Dmytro
ENG: The monograph has been prepared as part of comprehensive scientific research aimed at improving energy efficiency, digitalization, and the development of intelligent control systems. The materials presented reflect the results of many years of interdisciplinary research carried out with the participation of specialists from various scientific schools and universities. They provide a holistic understanding of modern trends in electric drive system control and form a scientific and practical basis for introducing innovative solutions in industry and transport. The discussed concepts of optimization, robust control, and the integration of renewable energy sources are closely linked to the transition to sustainable energy, automation of production processes, and infrastructure digitalization. Special attention is given to interaction with international research programs, which allows the use of advanced experience from Germany, Japan, the USA, and other countries in the field of digital twins, the industrial Internet of Things (Industrial IoT), andcyber-physical control systems.
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, Victor
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.
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, Dmytro
ENG: 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.
Assessment of Human-Operator’s Influence on Technical and Economic Indicators of the Excavator Production Cycle
(Dnipro University of Technology, Dnipro, 2025) Tytiuk, Valerii; Mrachkovskyi, D.; Chornyi, Oleksii; Kuznetsov, Vitalii V.; Tryputen, Mykola; Sivyakova, Galina
ENG: Purpose. Determining the influence of the parameters of the human-operator transfer function on the duration of the technological operation and the cyclic energy consumption of the electromechanical system of a straight shovel excavator equipped with electric drives of various types in order to further improve the human-machine control system of open-pit excavators by compensating for the inertia and nonlinearity of the human-operator characteristics. Methodology. Mathematical modeling of the human-machine control system of an excavator equipped with electric drives of various types, taking into account the dynamic characteristics of the human-operator, establishing regression dependencies of technical and economic indicators of the excavator on the parameters of the equivalent transfer function of the human-operator using design of experiments. Findings. The mathematical models of closed-loop control systems for the position of the bucket of a “straight shovel” excavator with an electric drive according to the Leonard system and a thyristor converter-motor electric drive have been implemented, which differ in that their structure takes into account the nonlinearity and inertia of the human operator and its influence on the performance of the human-machine system. Using the methods of the theory of experiment planning, we obtained regression dependences of the duration of the technological cycle and cycle energy consumption on the values of the time constant and the delay constant, which characterize the current state of the human-operator. The obtained regression models made it possible to evaluate the importance of the influence of various psycho-physiological factors of the human-operator on the technical and economic indicators of the excavator production cycle, which can serve as the basis for further optimization of the operation of mining excavators. Originality. For the first time, mathematical models of the electromechanical system of an excavator according to the “straight shovel” scheme are proposed, including models of electric drives of the main mechanisms, a model of the mechanical part of the excavator and a model of a human-operator, which made it possible to increase the accuracy of determining the energy consumption of the excavator and the time of the operating cycle. The regression models of technical and economic indicators of the excavator production cycle on the delay and inertia of the human-operator were obtained. It was found that the more influential factor is the transportation delay. Practical value. Mathematical models of an excavator with an electric drive based on the generator-motor system and an electric drive based on the thyristor converter-motor-motor system have been developed, including a model of the mechanical part of the excavator and a model of a human-operator. Regression models of the dependence of the duration of the excavator production cycle and its energy consumption on the delay and inertia of the human-operator are obtained. The proposed implementation of the human-machine excavator control system creates prerequisites for further increasing the level of automation of mining excavators.
Automatic Compensation of the Mill RolL Eccentricity in Terms of Limited Speed of Hydraulic Compression Devices
(Dnipro University of Technology, Dnipro, 2025) Boyko, O.; Kuvaiev, Victor; Potap, Oleg; Potap, M.; Rybalchenko, Maria O.
ENG: Purpose. To reduce deviation of vertical dimension (thickness) of rolled products from the specified value by enhancing the accuracy and shortening the setup time of an eccentricity compensation subsystem of mill rolls based on substantiation of an eccentricity compensation method. This method is based on an active search algorithm to determine the actual eccentricity parameters in real time, taking into account the actual response time of hydraulic compression devices (HCD) and investigating its effectiveness through simulation computer modelling. Methodology. The research was based on the analytical determination of the frequency characteristics of the AGC system in sheet metal rolling, considering the actual response time of HCD of a rolling mill as well as a comprehensive model of a rolling process in a quarto mill with rolling movement and an automatic thickness control system (ATCS) that compensates for eccentricity. The study was conducted by comparing the results of computer simulation modelling of the improved ATCS, whose algorithm took into account the HCD response time, with the performance indicators of the previous system, which did not consider this factor. Findings. It has been established that under the AGC thickness control conditions, the measured amplitude of a variable component of thickness does not match the amplitude of eccentricity due to the finite response time of HCD. The frequency characteristics of the AGC system have been determined analytically, taking into account the actual response time of HPD in a rolling mill. An improved procedure for determining the actual eccentricity amplitude in real time has been substantiated, which involves a temporary reduction in the HCD speed within the initial rolling section. A structure for an automated control system has been proposed for practical implementation of this procedure. It has been demonstrated that the proposed solutions allow for a threefold reduction in thickness variations caused by eccentricity compared to the corresponding performance indicators of the known eccentricity compensation systems with the AGC thickness control. Originality. The influence of the HCD response time on the accuracy of AGC thickness control systems for rolled products has been established. An approximate linear relationship has been identified between the ratio of the amplitude of thickness fluctuations caused by eccentricity and the amplitude of roll gap fluctuations relative to the roll speed and HCD response time under the AGC algorithm thickness control conditions. The improved procedure for determining the actual eccentricity amplitude in real time has been substantiated. Practical value. The effectiveness is substantiated of implementing an improved active search algorithm for determining the eccentricity parameters of mill rolls under the limited HCD response conditions in real time. This approach allows for a threefold reduction in the sheet thickness variability caused by roll eccentricity compared to the performance indicators of the known AGC thickness control systems, thereby ensuring the production of high-precision rolled products in Ukrainian sheet rolling mills.
Coefficient of Local Loss of Mechanical Energy of the Flow for a Mixture of Charge Materials
(Dnipro University of Technology, 2021) Selegej, Andriy Mikolayovich; Ivaschenko, Valeriy; Golovko, Vjacheslav Iljich; Kiriya, R.; Kvasova, Luydmila Sergijvna
ENG: Purpose. To determine the dependence of the coefficient of local losses of mechanical energy of flow of a twocomponent mixture of charge material on its depth, content of components, and average equivalent diameter of particles in the case of their freedispersed motion. Methodology. The value of the coefficient of local losses of mechanical energy was determined by the value of the hydraulic resistance of the fluid during its movement in open channels and pipes. In this paper, methods were used of comparative analysis, mathematical modeling and forecasting of dynamic processes in the flow of granular material. findings. Based on the results of theoretical studies, a mathematical model was obtained, the use of which allows calculating the coefficient of local losses of mechanical energy for the flow of a twocomponent mixture of charge materials with agglomerate particle sizes from 15 to 50 mm, pellets from 6 to 12 mm, coke from 10 to 60 mm. The developed model with satisfactory accuracy makes it possible to evaluate the movement of the charge from the indicated materials along the paths of the charging devices of blast furnaces at a speed in the range from 1.5 to 20 m/s and to determine the trajectories of the mixture of charge materials on the top with an accuracy of 0.2 m. It is noted that the calculation of the above coefficient by the known techniques is not accurate enough, which is associated with the uncertainty in the choice of a single average equivalent diameter of the particles of the two component charge. Comparative analysis of the developed model with the known models and experimental data indicates that the accuracy of calculating the dynamic parameters of a twocomponent flow of charge materials using the developed model increases by 5–10 % in comparison with calculations using the previously known models. Originality. For the first time, regularities of changes in the coefficient of internal mechanical losses of a twocomponent flow of charge materials from its depth, content of components, average equivalent particle diameters when moving along the paths of charging devices of blast furnaces have been established. practical value. Mathematical dependencies have been developed and can be used to determine the technological parameters of the charge of a modern blast furnace with different characteristics of the granulometry of the charge and the ratios of its components. This will increase the accuracy of predicting the course of the process under consideration, the degree of automation of the control systems for the technological process of the charge supply of blast furnaces, will make it possible to use expensive charge materials more efficiently, reduce energy consumption and reduce the harmful impact on the environment.
Complex of Mathematical Models and Methods to Calculate Pressure Effect on Sulfide Distribution in Steel
(Хмельницький національний університет, Україна, 2021) Selivyorstova, Tetjana V.; Selivyorstov, Vadim Yu.; Kuznecov, Vitaliy V.
ENG: Primary objective is to develop computational method to analyze digital pictures of sulfide prints, helping obtain qualitative image characteristics, and to formulate mathematical model of the distribution of sulphide inclusions to determine specific features of the pressure effect on the macrostructure formation of carbon steel castings flooded into the uncooled mold. The research was carried out using images of sulfide prints of templates cut of steel cylindrical castings; L500 steel was applied. The castings result from industrial tests of a method of gas-dynamic effect on the fusion in the foundry forms under the conditions of a casthouse of Dnipropetrovsk aggregate plant PJSC. Digital pictures of sulfide prints, obtained in terms of the increased rate of gas pressure and maximum pressure, were binarized; defective fra gments were removed; and zo ning took place. The developed computational method has been applied for fragments of images, representing different zones; data arrays have been received containing sizes and amounts of inclusions in the fragment. The developed computational method to analyze digital images of sulfide prints has been implemented. ASImprints software support has helped obtain qualitative characteristics of images; namely, distribution of amount of the certain-size sulfide inclusions. The computational method to analyze digital images of sulfide prints has made it possible to study the set of patterns of sulfide prints. The dependences have been obtained, describing specific features of sulfide inclusion distribution while varying gas-dynamic pressure method in terms of fusion in the casting form. It has been demonstrated that the distribution describes effectively the power-series distribution to compare with the exponential one. Mathematical model of the power -series distribution parameter dependence upon pressure has been developed. Deviation of the distribution parameters in terms of the experimental values and the model values has been evaluated. The research demonstrates the ways to apply an algorithm of simple recursive casting for quantitative analysis of digital images of sulfide prints. Use of ASImprints, being software implementation of the computational method to analyze digital images of sulfide prints making it possible to obtain qualitative characteristics of images, has helped identify that the increased pressure within a casting-device for gas injection system results in the increased specific amount of inclusions and the decreased specific zone of sulfide inclusions respectively. It has been defined that exponential function describes reliably the nature of sulfide inclusion distribution in the digital image of sulfide print. The research has demonstrated that fragments of a sulfide print, belonging to one zone, are statistically homogeneous. Thus, it is possible to analyze quantitively digital image zone of a sulfide print on its fragment. Mathematical model of dependence of sulfide inclusion distribution in carbon-steel castings in terms of gas-dynamic effect on fusion solidifying in a mold has been developed. The model may be applied to predict sulfide inclusion distribution within the selected zones of cross section of the cylindrical castings solidifying in the uncooled mold in terms of the preset mode of gas-dynamic effect.
Complex Solid-Phase Reduction in a Blast Furnace of Self-Healing Pellets of Cold Agglomeration Containing By-Product Carbon Materials of Metallurgical Production
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Vaniukov, Anton A.; Ivashchenko, Valerii P.; Ivanova, Liudmyla Kh.; Kovalov, M.; Tsybulia, Ye.
ENG: The reactions of direct and indirect reduction occurring during the heat treatment of self reducing pellets (SRP) have been studied. In this investigation Blast furnace (BF) sludge which contains particles of coke, has been included in the SRP blend as a source of solid reductant. In the SRP as a part ot the blast furnace burden occur the reactions simultaneously: inside of SRP-direct reduction by Csolid; gasification of carbon and indirect reduction by CO; and outside of SRP-indirect reduction of iron bearing oxides by reducing gas coming from the hearth of blast furnace through the column of charged materials. The experiments was performed continuously from the start temperature (~200 ˚C) to the experimental temperature (500 ˚C; 700 ˚C; 900 ˚C; 1100 ˚C) in argon free environment. Upon reaching the desired temperature argon was replaced by hydrogen during 30 minutes. After that the reduced probe of SRP was cooled in argon. The objective of the present work is to research a quantitate ratio of degree direct reduction inside of SRP and degree of indirect reduction outside of SRP on the top of the blast furnace.
Control of Drum Shear Electric Drive Using Self-Learning Artificial Neural Networks
(MDPI, Basel, Switzerland, 2025) Batyrbek, Alibek; Kuznetsov, Valeriy; Kuznetsov, Vitalii V.; Rojek, Artur; Kovalenko, Viktor; Tkalenko, Oleksandr; Tytiuk, Valerii; Krasovskyi, Pavlo
ENG: The objective of this work was to study the possibility of upgrading the control system of the drum shear mechanism by using neural network PI controllers to improve the efficiency of the sheet-metal cutting process. The developed detailed model of the mechanism, including a dual DC electric drive with three subordinate control loops for the voltage of the thyristor converter, current and speed of the motors, a 6-mass kinematic system with viscoelastic connections as well as a model of the metal cutting process, made it possible to uncover that the interaction of electric drives with the mechanical part leads to significant speed fluctuations during the cutting process, which worsens the quality of the sheet-metal edge. A modified system of current and speed controllers with built-in three-layer fitting neural networks as nonlinear components of proportional-integral channels is proposed. An algorithm for the fast learning of neural controllers using the gradient descent method in each cycle of calculating the controller signal is also proposed. The developed neuro-regulators make it possible to reduce the amplitude of speed fluctuations during the cutting process by four times, ensuring the effective damping of oscillations and reducing the duration of transient processes to 0.1 s.
Creative Methods as an Obligatory Component of the Technical Specialists Education in the Post-Industrial Era
(Faculty of Organization and Management at the Silesian University of Technology, Silesian Voivodeship, Poland, 2024) Molokanova, Valentyna M.; Petrenko, Vitaliy O.; Kuznetsov, Valeriy; Kuznetsov, Vitalii V.; Krol, Agnieszka; Kacprzak, Marzena; Wielewska, Izabela; Wyrzykowska, Barbara
ENG: Purpose: The article's objective is formalization of the model, the main stages and creative methods of training technical specialists, the definition of features and directions for further education development in the post-industrial era. The article is aimed at revealing the nature of creativity, highlighting the essence of the functions of methods of creative activity and their importance for students of technical specialties. Design/methodology/approach: The work uses critical analysis of scientific and methodological sources, system and convergent analysis methods, generalization and systematization of practical experience. The method of convergent generalization made it possible to identify key indicators of the model of creative competencies. The conceptual model of creative competence was developed based on the results of cooperation on the frame of master's programs for the project managers training. For the practical part of research, a qualitative method was used (participant observation, individual interview, tests). Findings: The need to train technical specialists in the methods of creative search using modern technologies, which allows to achieve the effects of the intellectual potential development for the individual, the state and society, is justified. An experiment on training project managers of two Ukrainian institutes in creative technologies proved the feasibility of implementing such training. Based on the calculation of the creative competencies’ development of the first- and second-year study technical specialists, the need to add a mandatory creative component to educational programs has been determined. Implications/Recommendations: To assess the quality of training, a methodology for assessing the level of competence has been applied. This made it possible to identify a low level of some competencies and, at the stage of improving the curriculum, plan the necessary corrective actions for the development of weak components of competencies. Since project-oriented learning is used, the model is similar to the model of the classical project life cycle and will be especially useful in the implementation of innovative projects in production. The article presents a framework for teaching students creative competence, which can be used by other educational institutions. Originality/value: The review of literary sources proved that so far very little attention has been paid to the development of creative competencies in students of technical specialties, although these competencies will be the competitive advantage of a person in the competition with artificial intelligence. The model of creative competencies for the technical specialists training is presented, which is divided into four areas, which in turn are divided into four components. These areas relate to the sampling and systematization of knowledge; adaptation to user requirements; awareness and dissemination of hidden knowledge; transition to the active use of knowledge.
Design of a Circuit-Field Model of a Closed-Loop Electric Drive System Based on a Switched Reluctance Motor
(Dniprovsky State Technical University, Kamianske, Ukraine, 2024) Kachura, Oleksii V.; Kolychev, Serhii V.; Suhal, Yevhen O.; Kuznetsov, Vitaliy V.; Nikolenko, Anatolii V.
ENG: The distribution of switched reluctance motors (SRM) is due to their specific properties: high reliability due to the absence of sliding contacts, precise positioning, wide range of regulation. These properties allow the use of SRM in various adjustable electric drives in conjunction with semiconductor control systems. The complexity of the study such systems is a correct representation of both, the control system and the motor, taking into account their mutual influence and energy exchange. In addition, as a rule, SRM have a rather specific design, which limits the use of classical methods for their calculation and causes the use of numerical methods. The paper presents a mathematical model of a closed loop drive system on the rotor position and speed, based on the SRM. As a result of the unification of the SRM field model constructed on the basis of the Laplace and Poisson equations and the circuit model of the control system, a circuit-field mathematical model is obtained. The mathematical model takes into account the design features of the motor and allows to explore a drive system in dynamic modes of operation. An algorithm for switching power inverter keys for four phases of the SRM is developed. From the obtained values of magnetic induction and tension tensors the electromagnetic moment of the motor calculated. Electromagnetic and electromechanical parameters of the serial SRM-57-100-4 in the start-up mode obtained for the proposed model.
Development of a Digital Twin of a DC Motor Using NARX Artificial Neural Networks
(MDPI, Basel, Switzerland, 2025) Busher, Victor; Kuznetsov, Valeriy; Ciekanowski, Zbigniew; Rojek, Artur; Grudniewski, Tomasz; Druzhinina, Natalya; Kuznetsov, Vitalii V.; Tryputen, Mykola; Hubskyi, Petro V.; Batyrbek, Alibek
ENG: This study presents the development process of a digital twin for a complex dynamic object using Artificial Neural Networks. A separately excited DC motor is considered as an example, which, despite its well-known electromechanical properties, remains a non-trivial object for neural network modeling. It is shown that describing the motor using a generalized neural network with various configurations does not yield satisfactory results. The optimal solution was based on a separation into two distinct nonlinear autoregressive with exogenous inputs (NARX) artificial neural networks with cross-connections for the two main machine variables: one for modeling the armature current with exogenous inputs of voltage and armature speed, and another for modeling the angular speed with inputs of voltage and armature current. Both neural networks are characterized by a relatively small number of neurons in the hidden layer and a time delay of no more than 3 time steps. This solution, consistent with the physical understanding of the motor as an object where electromagnetic energy is converted into thermal and mechanical energy (and vice versa), allows the model to be calibrated for the ideal no-load mode and subsequently account for the influence of torque loads of various natures and changes in the control object parameters over a wide range. The study demonstrates that even for modeling an object such as a DC electric drive with cascaded control, reducing errors at the boundaries of the known operating range requires generating test signals covering approximately 120% of the nominal speed range and 250–400% of the nominal current. Analysis of various test signals revealed that training with a sequence of step changes and linear variations across the entire operating range of armature current and speed provides higher accuracy compared to training with random or uniform signals. Furthermore, to ensure the neural network model’s functionality under varying load torque, a mechanical load observer was developed, and a model architecture incorporating an additional input for disturbance was proposed. The SEDCM_NARX_LOAD neural network model demonstrates a theoretically justified response to load application, although dynamic and static errors arise. In the experiment, the current error was 7.4%, and the speed error was 0.5%. The practical significance of the research lies in the potential use of the proposed model for simulating dynamic and static operational modes of electromechanical systems, tuning controllers, and testing control strategies without employing a physical motor.
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.
Development of Fast Spheroidizing Annealing Modes and Modeling of the Intensification Process of Cementite Spheroidization of Low-Carbon Steels
(TECHNOLOGY CENTER PC, Kharkiv, 2026) Shvachych, Hennadii H.; Sobolenko, Mariia O.; Ivashchenko, Valerii P.; Manko, Tamara; Moroz, Borys; Meshcheriakov, Leonid
ENG: The object of research is the process of cementite spheroidization of 20Г2Р low-carbon steel 2during heat treatment, in particular spheroidizing annealing. Special attention in conducting research is paid to the influence of the initial structural state of the steel, temperature regimes and heating methods on the formation of the microstructure of the workpiece. Traditional methods of spheroidizing annealing are characterized by a significant duration of the regime, which reaches more than 10 hours and, in connection with this, energy costs, which limits the efficiency of the technological process. This is especially true for low-carbon steels with a relatively weak thermodynamic stimulus for spheroidization. The research problem is the need to reduce the duration of spheroidizing annealing of steel and reduce energy costs while ensuring a uniform distribution of cementite globules in the ferrite matrix. The scientific novelty of the obtained results lies in the development of high-speed regimes of spheroidizing annealing of 20Г2Р steel using the initial ferritic-bainite structure and non-isothermal holding with increasing temperature, in contrast to known studies based on long isothermal holdings. It is shown that the total duration of spheroidizing annealing of low-carbon steels significantly depends on the initial structural state of the workpiece. It is established that the transition from ferritic-pearlitic to ferritic-bainite initial structural state provides a reduction in the duration of cementite spheroidization from 1500–1800 s to 200–450 s. The features of the intensification of spheroidizing annealing of low-carbon steels have been studied and the influence of changes in the values of thermodynamic and kinetic factors during structural transformation has been established. The effectiveness of using non-isothermal holding with increasing temperature in a certain temperature range and optimization of spheroidizing treatment parameters has been proven. The practical significance of the results obtained lies in the implementation of the developed high-speed modes of spheroidizing annealing of 20Г2Р low-carbon steel for the production of coiled strip and wire with a diameter of 6.0–20.0 mm. The obtained structural states of the blanks provide the necessary set of properties for the subsequent manufacture of metal products by cold drawing, in particular products of complex configuration. The proposed approaches are fully suitable and meet the requirements for technological and mechanical properties of blanks for the manufacture of metal products by cold drawing.
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 V.; Zachepa, Iurii; Chencheva, Olga; Chornyi, Oleksii; Kovzel, Maksim; Kovalenko, Viktor; Babyak, Mykola O.; Levchenko, Serhii
ENG: 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.
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, Olha
ENG: 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.
Dynamic Modeling of Induction Motor Performance under Power Quality Disturbances
(Український державний університет науки і технологій, ННІ «Дніпровський металургійний інститут», ІВК ≪Системні технології≫, Дніпро, 2026) Kuznetsov, Vitalii V.; Nikolenko, Anatolii V.; Stopkin, Vasyl V.; Martyntsev, Viacheslav; Tuhushy, Roman; Teslenko, Ivan
ENG: The paper presents a dynamic electromagnetic model of a three-phase squirrel-cage asynchronous motor developed to simulate its operation under real power quality disturbances. The relevance of this work is driven by the increasing impact of electromagnetic compatibility issues and energy losses in industrial systems exposed to voltage asymmetry and harmonic distortion–conditions typical for networks with nonlinear loads such as welding equipment, arc furnaces, and frequency converters. Traditional motor models, which assume ideal supply conditions, are not sufficient for accurately predicting performance degradation under such disturbances. To address this limitation, the proposed model is based on space-time complexes and an extended form of the Park–Gorev equations. A key feature of the model is the inclusion of magnetic core saturation, represented through a polynomial dependence of mutual inductance on magnetizing current, enabling more realistic simulation under high-load and unbalanced conditions. The model was tested on an MTKH 112-6 motor (5.3 kW) under two scenarios: ideal sinusoidal voltage and distorted asymmetric supply with harmonics up to the 10th order. The results showed that voltage distortion leads to increased losses in the stator (from 491.3 W to 498.3 W) and rotor (from 652.2 W to 661.5 W), a decrease in efficiency (from 81.4% to 81.2%), and a significant drop in power factor (from 0.98 to 0.90). Additionally, distorted current waveforms and torque pulsations confirmed higher electromagnetic stress. The model demonstrated strong agreement with experimental data (RMSE < 4%), confirming its reliability for applications in diagnostics, predictive maintenance, digital twins, and simulation environments. Unlike traditional Fourier-based approaches, the use of space-time complexes enables comprehensive modeling of both steady-state and transient processes without explicit harmonic decomposition. This research contributes to the development of energy-efficient and intelligent industrial systems. Future work will focus on incorporating stochastic elements to account for dynamic variations in power quality, supporting predictive control and advanced automation within Industry 4.0.
Electrotechnical Materials
(RS Global, Warsaw, Poland, 2021) Tsyplenkov, Dmytro; Nikolenko, Anatolii V.; Kolb, Andrii; Grebeniuk, Andrii; Kuznetsov, Vitalii V.; Babyak, Mykola O.; Kovalenko, Viktor
ENG: The regularities of processes and phenomena that occur in dielectric, conductive, semiconductor and magnetic materials as part of electrical and electronic devices under the influence of energy of electric, magnetic and thermal fields are considered. The main feature of the textbook is a detailed structuring of educational material, focusing largely on the distance form of learning, as well as demonstration of the close relationship of the properties of various electrical materials and the basics of electrical engineering on specific examples. The manual is intended for students of specialties: 141 - "Electrical Energetics, Electrical Engineering and Electromechanics" and 275 - "Transport technologies", as well as for students of other specialties of higher education, which are related to the study of disciplines of electrical engineering and electronic computer science.
Enhancing Power Quality within the Context of Industrial Enterprises: Strategies for Improvement
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2023) Tryputen, Mykola; Kuznetsov, Vitaliy V.; Nikolenko, Anatoliy V.
ENG: The paper analyzes negative impact of poor-quality electricity on the performance of electrical installations. Particular attention is paid to the ways to improve power quality under the conditions of industrial enterprises. Use of “individual” LC-filters to protect extra important electric drives; use of “group” devices to compensate negative effect of noisy electricity at a workshop level (power active rectifiers are meant with their potential integration into the available converters for the controlled electric drives); and to inhibit voltage distortions within the areas of their origination (i.e. the mains protection against the root cause) are possible means to solve the problems.
Estimating the Probability of the Emergency Operation of the Quarry Electric Locomotive Traction Electric Drive
(RS Global Sp. z O.O., Poland, 2021) Artemenko, Artem; Chornyi, Oleksii; Sydorenko, Valeriy; Serhiienko, Serhii; Zachepa, Yurii; Kuznetsov, Vitaliy; Kuznetsova, Alisa
ENG: The paper deals with the problem of the assessment of the functionality of the multi-motor direct current traction electric drive of the quarry electric locomotive. The problem of the failure of electric drive motors because of extremely unsatisfactory state of the rail tracks and the wear of wheel pairs is analyzed. Taking into account the number of the existing repaired electric motors the probability of fitting up the traction electric drive with the electric motors with the widest electrical parameters variety is determined.
Forecasting the Power Generation of a Solar Power Plant Taking into Account the Statistical Characteristics of Meteorological Conditions
(MDPI, Basel, Switzerland, 2025) Kuznetsov, Vitalii V.; Kuznetsov, Valeriy; Ciekanowski, Zbigniew; Druzhinin, Valeriy; Tytiuk, Valerii; Rojek, Artur; Grudniewski, Tomasz; Kovalenko, Viktor
ENG: The integration of solar generation into national energy balances is associated with a wide range of technical, economic, and organizational challenges, the solution of which requires the adoption of innovative strategies for energy system management. The inherent variability of electricity production, driven by fluctuating climatic conditions, complicates system balancing processes and necessitates the reservation of capacities from conventional energy sources to ensure reliability. Under modern market conditions, the pricing of generated electricity is commonly based on day-ahead forecasts of day energy yield, which significantly affects the economic performance of solar power plants. Consequently, achieving high accuracy in day-ahead electricity production forecasting is a critical and highly relevant task. To address this challenge, a physico-statistical model has been developed, in which the analytical approximation of daily electricity generation is represented as a function of a random variable—cloud cover—modeled by a β-distribution. Analytical expressions were derived for calculating the mathematical expectation and variance of daily electricity generation as functions of the β-distribution parameters of cloudiness. The analytical approximation of daily generation deviates from the exact value, obtained through hourly integration, by an average of 3.9%. The relative forecasting error of electricity production, when using the mathematical expectation of cloudiness compared to the analytical approximation of daily generation, reaches 15.2%. The proposed forecasting method, based on a β-parametric cloudiness model, enhances the accuracy of day-ahead production forecasts, improves the economic efficiency of solar power plants, and contributes to strengthening the stability and reliability of power systems with a substantial share of solar generation.
The Generalized Chaotic System in the Hyper-Complex Form and Its Transformations
(Springer, Cham, 2022) Voliansky, Roman; Volianska, Nina; Kuznetsov, Vitaliy V.; Tryputen, Mykola; Kuznetsova, Alisa; Tryputen, Maksym
ENG: The paper deals with the development of the mathematical backgrounds to design the novel chaotic systems by transforming existent ones. These backgrounds are based on using well-known shift, rotation, and scale transformations and we offer using hyper-complex numbers to simplify these transformations and represent the transformed chaotic system by using the one 1st order ordinary differential equation. In such form all well known, newly discovered and unknown chaotic systems have the similar mathematical models that are differs only by used nonlinear function of hyper complex variable in the right hand expression. That is why the consideration chaotic system dynamic in the hyper-complex domain allows us to simplify initial system definition as well without applying any transformations. This fact simplifies mathematical definition of chaotic systems and their modeling and simulation. The right-hand expression of the transformed equation in this case are defined as the combination of transformation hyper-complex numbers and source system nonlinearity which is given in the hyper-complex domain. We offer to use variable transformation factors to improve the performance of the considered chaotic system. Since the above-mentioned variable factors can be produced by other chaotic systems, we suggest designing the novel chaotic system by combining existed ones with the linear transformations. As an example, we consider the transformation of the well-known Lorenz system and show the differences between the source system and target one.
High-Performance Multiprocessor Systems
(Український державний університет науки і технологій, ННІ «Інститут промислових та бізнес технологій», 2022) Ivashchenko, Valery Petrovych; Shvachych, Gennady Grygorovych; Ivashchenko, Olena Valerievna; Sushko, Larisa Fedorovna
ENG: The paper is devoted to the modeling of high-performance multiprocessor architecture for data processing systems used to solve problems with an expandable calculations' area. The proposed system is characterized by high reliability and high energy efficiency. The system contains a separate reconfigurable network for the exchange of data between computing nodes, managed switches. The system also provides network booting nodes and redundancy mechanism of key components.
Identification of Induction Motor Parameters in Vector Control Electric Drives
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2024) Kuznetsov, Vitaliy V.; Tsyplenkov, Dmytro; Nikolenko, Anatoliy V.
ENG: The paper is devoted to the questions of identifying coordinates and parameters of asynchronous engine and the increase of the quality of electromechanical transition processes of asynchronous electric drive with a vector control at indirect determination.
Identification of the Thermal Process in an Induction Motor
(Dnipro University of Technology, Dnipro, Ukraine, 2022) Kuznetsov, Vitalii V.; Tryputen, M.; Nikolenko, Anatolii V.; Tsyplenkov, Dmytro; Kuvaiev, Victor; Savvin, Oleksandr V.
ENG: Purpose: synthesis of a mathematical model of an asynchronous motor, taking into account the impact of changes in the quality of electricity on the processes of heating and heat exchange for an economically justified choice of means of protection. Methodology: Theoretical substantiation of the expediency of using a one-mass thermal model of an asynchronous motor, for the conditions of operation of the latter in conditions of low-quality electricity, in order to determine losses in it. Results: Experimental studies of the operation of an asynchronous motor at nominal load were carried out. The obtained results of the measurements made it possible to determine the parameters of the single-mass thermal model, the heat transfer coefficient of the engine, and the coefficient of its heat capacity. A single-mass thermal model of an induction motor is a mathematical model used to describe the thermal processes occurring in an induction motor. This model is based on the assumption that all motor elements can be combined into one mass that heats up during engine operation. The model assumes that the thermal capacity of the motor is a constant, and the heat flow that is released during the operation of the motor is proportional to the square of the current passing through the motor windings. In addition, the model assumes the presence of thermal conductivity between the mass of the motor and the external environment, which affects the rate of heat dissipation. Scientific novelty: A methodology for determining losses in an asynchronous motor using a synthesized mathematical model is proposed, taking into account the influence of changes in the quality of electricity on the processes of heating and heat exchange in it. Practical significance: The obtained results indicate the adequacy of the proposed thermal model of an asynchronous motor operating in a network with low-quality electricity. Taking into account the fact that for many types of engines in the reference literature, there are no necessary data on the coefficients of heat transfer and heat capacity, and only the thermal time constants for certain types of engines are given, the value of the specified parameters of the model can be obtained on the basis of the methodology presented in the work. A single-mass thermal model can be useful for analyzing the thermal processes occurring in an induction motor and for improving the efficiency of the motor. In particular, it can help determine the optimal operating temperature of the motor, as well as calculate the necessary cooling system to ensure stable operation of the motor under conditions of variable load and temperature conditions.
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.
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.
Impact of Power Quality on a Synchronous Motor Performance: A Dynamic Model Approach
(Видавництво МДПУ ім. Б. Хмельницького, Запоріжжя, 2025) Kuznetsov, Vitalii V.; Spirintsev, Dmytro V.; Shlykov, S. Yu.; Herashchenko, A.; Kryvenko, O. V.
ENG: The paper presents an advanced dynamic electromagnetic model of a three-phase squirrel-cage asynchronous motor designed to simulate performance under real-world power quality disturbances. The motivation stems from the growing need to address electromagnetic compatibility issues and energy losses in industrial systems exposed to asymmetric voltages and harmonic distortion-conditions common in environments with nonlinear loads such as welding equipment, arc furnaces, and frequency converters. Conventional motor models, typically assuming ideal supply conditions, are inadequate for predicting performance degradation due to poor power quality. To overcome this, the proposed model utilizes space-time complexes and an extended version of the Park-Gorev equations. A key innovation is the introduction of nonlinear magnetic saturation, modeled via a polynomial relationship between mutual inductance and the magnetizing current. This feature enables a more accurate representation of core material behavior under high-load or unbalanced conditions. The simulation was conducted for an MTKH 112-6 asynchronous motor rated at 5.3 kW under two scenarios: (1) ideal sinusoidal three-phase voltage, and (2) real distorted voltage with significant asymmetry and harmonic components up to the 10th order. The analysis revealed that even moderate distortions led to increased stator and rotor losses (from 491.3 W to 498.3 W and 652.2 W to 661.5 W, respectively), a drop in overall efficiency (from 81.4% to 81.2%), and a marked reduction in power factor (from 0.98 to 0.90). Furthermore, current waveform analysis showed visible harmonic deformation, and torque pulsation diagrams indicated increased electromagnetic stress on the motor structure. The proposed model demonstrated a high degree of agreement with experimental data (RMSE < 4%), validating its applicability for use in diagnostics, predictive maintenance, digital twin platforms, and educational simulation environments. Unlike Fourier-based harmonic analysis, the use of space-time complexes allows the system to be modeled holistically, capturing transient behavior and steady-state responses without needing individual harmonic decomposition. This work contributes to the broader field of smart manufacturing and energy-efficient industrial automation. Future improvements include incorporating stochastic modeling to account for dynamic grid variations, enabling probabilistic forecasting and automated control strategies within Industry 4.0 frameworks.
Implementation of Value-Oriented Project Portfolio Management for the Development of Complex System
(WSGE University of Applied Sciences in Józefów, Poland, 2024) Molokanova, Valentyna M.; Kuznetsov, Vitalii V.; Kuznetsov, Valeriy; Petrenko, Vitaliy O.; Krol, Agnieszka; Ciekanowski, Zbigniew
ENG: The formation of a development portfolio is one of the key challenges facing any level of system. The aim of the article is to present a model of optimal value-oriented portfolio formation for the development of a complex system, taking into account mutual influence of portfolio components on each other. It analyses the method¬ology of portfolio development management of organizations, considers different approaches to forming a portfolio of projects, proposes the formation of a portfo¬lio of organization development based on the value-oriented approach, considers multi-criteria model of project selection in the organization development portfolio, taking into account the mutual influence of the components of the portfolio on each other. As the basic method of forming a portfolio of regional community develop¬ment using the value-based approach, taking into account the existing limits on the total value of the portfolio in the computable period is proposed. The problems of incomplete application of the portfolio management methodology in the system of public development management in Ukraine were reflected. The paper determined that although the project approach is increasingly used in Ukraine to manage the de¬velopment of territories, for many acute problems portfolio development management is not used. The necessity of managers training for portfolio management of regional systems development has been substantiated. Suggested the use of value-oriented methodology of project management to manage regional development, which significantly improves the quality of planning and effectiveness of the implementation of development strategy through projects.
Improvement of Pig Iron Production Technology by Using the Useful Properties of the Potential of Secondary Resources of Raw Materials and Fuels
(Ukrainian State University of Science and Technologies, Dnipro, 2026) Mishalkin, A. P.; Ivashchenko, Valerii P.; Yaroshenko, O. V.; Petrenko, Vitalii O.; Chumak, D. D.
ENG: The scientific and technical relevance of the study lies in determining the directions for improving the ways of using the useful properties of secondary resources in order to intensify the blast furnace process, increase its energy efficiency and reduce pollutant emissions. At the same time, economic efficiency is achieved by reducing the cost of purchasing primary raw materials and reducing waste generation, which corresponds to modern concepts of sustainable development on the way to "green" metallurgy. Purpose of the study. Scientific and practical substantiation of directions for improving the technology of pig iron production through the use of useful properties of secondary resources of raw materials and fuels that have a man-made origin. It is aimed at increasing the level of energy efficiency and improving the slag regime of the blast furnace process, reducing the man-made load on the environment of industrially developed regions of Ukraine. To achieve this goal, the following theoretical and practical tasks will be solved in the study: 1. The analysis of the current state of use of secondary resources of mineral raw materials and fuel in blast furnace production in the conditions of world and domestic metallurgical enterprises has been carried out. 2. The physicochemical properties of the most common types of secondary resources (man-made wastes of metallurgical origin: dust, sludge, scale, production of metallurgical lime: fractions from gas cleaning devices and heat treatment products of waste of plant origin, which are sources of pyrocarbon) have been investigated. Further - determination of the spectrum of their probable purpose, impact on the features and indicators of the blast furnace process, as well as justification of rational ways of their preparation and use. 3. Rational shares of substitution of traditional raw materials and fuels with secondary materials in the blast furnace process are substantiated, the use of which will not reduce the quality of pig iron and will not increase the specific consumption of coke. Their influence on physicochemical and heat-gas-dynamic processes, which is reflected in the characteristic zones of the blast furnace, has been studied. 4. The optimal technological schemes and recommendations for the methods of introduction and rational specific consumption of innovative materials based on man-made wastes have been determined, which will ensure the maximum level of use of their useful properties in the material and thermal balances of the blast furnace process. 5. The technological and environmental advantages of introducing into the blast furnace process a monomaterial, the composition, physicochemical features and spectrum of purpose of which are formed by heat treatment of a mixture of man-made industrial waste, are evaluated and their prospects as a substitute for the corresponding part of pulverized coal fuel (PCF) and fluxes are determined. Research methods. When conducting a comprehensive study, the following methods will be used: - analysis and generalization of materials of scientific and technical literature and patent sources, coordination of their results in accordance with modern trends and the best results of the practice of using secondary resources in blast furnace production; - physicochemical methods of analysis chemical, thermogravimetric, to determine the composition, structure, metallurgical value, probable spectrum of purpose and reactivity of secondary resources of materials - substitutes for iron ore raw materials, coke and pulverized coal fuel (PCF); - thermodynamic forecasting and kinetic modeling of the behavior of experimental materials of secondary origin under the conditions of their heat treatment to assess the influence of their properties on the course of physical and chemical processes and transformations to the thermal and gas-dynamic regime of the blast furnace. The expected results of the study should also include: - development of scientifically grounded recommendations for the effective use of useful properties of the initial potentials of secondary resources of raw materials and fuel in blast furnace production; - establishment of quantitative ratios regarding rational levels of substitution of traditional fuel and raw materials with secondary ones, without reducing the productivity of the furnace and the quality of pig iron while reducing the specific consumption of lime and PCF; - development of a method for the implementation of a complex technological scheme for the preparation, heat treatment of experimental mixtures based on components of mineral raw materials and fuel, followed by the use of an innovative product in the conditions of blast furnace production of pig iron; Scientific novelty of the work. For the first time, systematically, on the basis of the results of an analytical and practical study, the energy efficiency of production and use in the blast furnace process of a two-component monomaterial based on dispersed waste from the production of lime and materials – waste of plant origin, obtained by implementing the effect of their pyrolysis under conditions of joint heat treatment of the initial mixture layer, was substantiated, tested on high-temperature models, poured thermal, in an inclined rotary drum-type furnace. For the first time, a resource-efficient and results-efficient approach has been used to assess the efficiency of the use of materials based on secondary resources of metallurgical and plant origin, based on an integrated combination of the results of thermodynamic forecasting, physical modeling and taking into account the provisions of the exergical methodology for assessing the energy efficiency of the objects of study. Methodological bases have been developed for the selection of rational schemes for the introduction of complex materials based on secondary materials into the blast furnace charge and in the air blast flow to stabilize gas-dynamic conditions in the charge layer, intensify recovery processes with a decrease in the specific consumption of coke per ton of liquid pig iron. The regularities of the influence of the composition and dispersion of secondary resources on the gas-dynamic and thermal parameters of blast furnace smelting have been revealed, which makes it possible to increase the accuracy of predicting the furnace course. It has been proved that the use of materials based on secondary resources of mineral raw materials and fuels can provide the effects of increasing the energy efficiency of pig iron production and reducing the environmental burden, which meets the requirements of sustainable development and the concept of "green metallurgy".
Improvement of Technical Service of Track Circuits
(Institute of Electrical and Electronics Engineers, IEEE, 2019) Serdiuk, Tetiana M.; Kuznetsov, Vitaliy V.; Serdiuk, Kseniia; Nikolenko, Anatoliy V.; Kuznetsova, Yevheniia; Kuznetsova, Alisa
ENG: The automated method of measuring the time and amplitude parameters of code current and parameters of track circuits (input impedance of the track circuit, a characteristic impedance, a propagation constant) were elaborated. The mathematic model of track circuits’ channel of transferring code current was improved and considered in this paper. The algorithms of definition of parameters of track circuit are offered.
Improvement of the Process of Conducting Arc-Free Ferronickel Melting in a Six-Electrode Furnace
(Elsevier/SSRN, 2021) Bezugliy, Anatolii V.; Nikolenko, Anatolii V.; Shevchenko, D. V.; Ovcharuk, Anatolii N.; Kuvaev, Viktor Iu.; Bezugliy, V. A.; Zamkovoy, O. V.
ENG: Purpose. The aim of the authors is to find a technical solution to effectively control the appearance of an arc discharge in the subelectrode space of each of the six electrodes in submerged-arc furnaces from operational point of view. Methodology. A scheme was drawn up for modeling of the furnace circuit of a six-electrode furnace, which made it possible to obtain the zero point offset voltage and control its third harmonic and other components. For this purpose, two three-phase systems were created in the electrical circuit of the six-electrode furnace, consisting of half-phases of odd and even electrodes. For each of these systems, an artificial symmetric "star" was created separately. The neutral offset voltage for each of the systems was measured between the star zero point and the conductive hearth. Findings. Analysis of the harmonic composition of the shape of the neutral offset voltage curve, created by using an artificial symmetric star, made it possible to obtain a number of information (dependencies) that can be used in control algorithms. The proposed measuring scheme was tested on operation industrial six-electrode furnace of the Pobuzhsky Ferronickel Plant. During the melting, arcs were artificially created under the electrodes. Wherein: 1) the presence of an arc discharge was confirmed by the appearance of the third harmonic of the zero point offset voltage; 2) phase shifts of the first harmonic unambiguously indicated to the electrode with an arc discharge. Practical value The proposed method for monitoring the presence of electric arcs under the electrodes can be used to control ore-thermal furnaces both independently and as an addition to the already used systems for monitoring and controlling the electric mode of six-electrode furnaces.
Improving the Efficiency of the Ferroalloy Smelting Process in Electric Arc Furnaces by Improving Control and Management of Technological Modes
(Український державний університет науки і технологій, ННІ «Дніпровський металургійний інститут», ІВК ≪Системні технології≫, Дніпро, 2025) Nikolenko, Anatolii V.; Nezhurin, Vadym; Kuvaev, Viktor; Verovkin, Oleksandr; Bashko, Volodymyr; Kopysov, Vladyslav; Koliadenko, Oleksandr
ENG: The article addresses the issues of improving the efficiency of ferroalloy smelting in electric arc furnaces by enhancing the control and management of technological regimes. Recent global trends, such as the increase in the production of high-quality alloy steels and semiconductor products, have led to a sharp rise in the demand for ferroalloys and crystalline silicon. In this context, the intensification of technological processes and the optimization of energy consumption in ferroalloy electric furnaces have become particularly relevant. The ferroalloy smelting process is based on the carbothermic reduction of metals from their oxides, occurring at high temperatures with significant heat absorption. Although the mechanisms and kinetics of the main reduction reactions have been well studied, in industrial conditions, the techno-economic indicators of the process are significantly inferior to those achieved in laboratory settings. The extraction rate of target elements decreases to 75–80%, and the energy consumption exceeds the theoretically necessary amount by 1.5–2 times. Traditional approaches to improving the ferroalloy smelting process through the enhancement of furnace designs and the selection of charge materials with specific physico-chemical properties have largely exhausted their potential. In the context of continuously rising energy costs and deteriorating raw material quality, the urgent problem now lies in implementing fundamentally new approaches to technological process control, focused on detailed monitoring and analysis of the furnace’s current state. The authors justify the necessity of transitioning from the "input-output" control system to a more advanced "input-state-output" principle, which enables real-time analysis of the furnace workspace parameters and prompt influence on the course of the technological process. In particular, significant attention is devoted to the development of methods for analyzing the electrical, thermal, and physico-chemical characteristics of the active zone of the furnace, which determine the main transformation processes of the charge. The paper discusses the design features of electric arc furnaces and describes the structure of the workspace for different types of processes - slag-free and slag-forming. It is shown that the distribution of energy among the zones of the charge, the arc, and the melt has a substantial impact on the techno-economic indicators of production. The peculiarities of arc burning, heat transfer processes, and ionization in the gas cavities of the furnaces are studied. The article highlights the main methods for investigating processes in furnaces: probing, analyzing oscillograms of current and voltage, determining the resistances of the charge and melt, as well as modern methods for assessing power distribution across furnace zones based on measurements of electrical parameters. Special attention is paid to the problem of increasing the accuracy of assessing the parameters of energy processes without interfering with the technological process. The authors emphasize the importance of optimizing the modes of electric power supply and the structural parameters of furnaces to ensure the stability of the bath operation, reduce the dispersion of fluctuations, and minimize losses. Methods for selecting optimal electrode immersion parameters, managing charge regimes, and selecting charge materials considering their electrophysical properties are presented. The article makes a significant contribution to the creation of a scientific basis for improving the efficiency of ferroalloy smelting, which is of particular importance in the context of the modern energy crisis and the growing demands for the quality of metallurgical industry products.
Improving the Reliability of Simulating the Operation of an Induction Motor in Solving the Technical and Economic Problem
(Springer, Cham, 2020) Tryputen, Mykola; Kuznetsov, Vitaliy; Kuznetsova, Alisa; Tryputen, Maksym; Kuznetsova, Yevheniia; Serdiuk, Tetiana M.
ENG: The article is devoted to the control of the statistical laws of linear voltages reproduced on a computer during computational studies on an energy-economic model when solving the problem of choosing protection tools for induction motors operating in workshop electric networks of industrial enterprises with low-quality electricity. Simultaneous and continuous estimation of average values, variances, autocorrelation and cross-correlation functions of harmonics of linear voltages is based on the adaptive approach. The article presents mathematical expressions for correcting the values of statistical quantities with the accumulation of information and proposes structural schemes for a comprehensive analysis of the results of reproduction of random variables and functions on a computer. The results of checking the values of the average values and dispersions of six harmonics of simulated linear voltages supplying an induction motor with a power of 7.5 kW are shown for the conditions of the rolling shop No. 1 of Dneprospetsstal LLC.
Increasing the Reliability of Simulation of Asynchronous Motor Operation Based on an Adaptive Approach
(Український державний університет науки і технологій, ННІ «Дніпровський металургійний інститут», ІВК ≪Системні технології≫, Дніпро, 2025) Tryputen, Mykola; Kuznetsov, Vitalii V.; Verovkin, Oleksandr; Koliadenko, Oleksandr
ENG: This research focuses on improving the reliability of simulating the operation of induction motors when solving technical and economic problems related to the selection of protection systems for electric drives operating in industrial power networks with poor power quality. The presence of voltage asymmetry, harmonic distortions, and other power quality issues in workshop networks significantly affects the performance and service life of induction motors, increasing energy losses and maintenance costs. The article proposes a power and economic model that allows conducting computational experiments to determine the optimal solution for improving power supply quality. A key element of the model is the system for generating and controlling linear voltage parameters, which ensures compliance of the simulated signals with their statistical regularities observed in real industrial conditions. The research introduces adaptive algorithms for the continuous and simultaneous assessment of average values, variances, autocorrelation, and cross-correlation functions of voltage harmonics. Mathematical expressions for their correction during the accumulation of information are presented. Structural schemes of control systems for both analog and digital modeling of voltage processes are proposed, allowing for real-time monitoring of the reliability of generated data. The simulation results were verified through statistical hypothesis testing for the average values and variances of the generated voltage harmonics. Experimental studies were carried out in the rolling shop No. 1 of Dneprospetsstal LLC, where significant voltage distortions are caused by the operation of powerful semiconductor converters. The results confirmed the adequacy of the proposed modeling approach and its applicability for making economically sound decisions regarding the choice of technical solutions for voltage quality improvement. This work contributes to the field of energy efficiency in industrial enterprises by providing a methodological basis for the reliable simulation of induction motor operation in the presence of distorted power supply conditions. The proposed approach allows reducing the cost and duration of experimental studies by replacing them with validated computational modeling.
The Influence of Reactive Power Compensation Methods on the Burning Characteristics of Shunted Electric Arc in an Ore Reduction Furnace
(Dnipro University of Technology, Dnipro, 2024) Nezhurin, Vadym I.; Nikolenko, Anatolii V.; Tsyplenkov, D.; Bobrov, O.; Fedorov, Serhii S.; Savvin, Oleksandr V.
ENG: The purpose of the work was to study the effect of compensation on the stability of the combustion of an electric arc in the furnace bath. Methodology. The results of the research of operating furnaces by traditional methods, such as measurement and oscillography of the form of voltage and current on the electrodes during the smelting of ferroalloys, were used. Results. Schemes of transverse capacitive compensation on the high or medium voltage side and longitudinal capacitive compensation in the medium voltage circuit of the furnace transformer are used for Electric ore reduction furnaces. Electric ore reduction furnaces are large consumers of reactive power, and their power has already reached such an amount that the value of the inductive voltage drop becomes unacceptably large; and their natural power factor does not exceed the value of 0.6–0.7. Compensation of the reactive power of the longitudinal compensation devices is traditionally resolved by usage of capacitor banks. Determined that longitudinal compensation devices are based on the phenomenon of voltage resonance, then if there are active, inductive and capacitive resistances in the furnace circuit – the arc burns continuously, even in the case of partial compensation. This mode occurs at a power factor of about 0.85. In case of full compensation of the inductive component of resistance of the furnace circuit, the mode of arc burning changes and becomes intermittent. Scientific novelty. Determined that with a fixed value of the power factor and the value of conductivity bc, it is very difficult to achieve ideal current resonance, and when bc = −⌂bl+bl+⌂blс the burning mode of the electric arc will be continuous; however, if the capacitive conductivity becomes more inductive, overcompensation is possible. In the case of transverse compensation, the total power of the furnace unit should be approximately 10% higher. Practical significance. The results obtained can be used for a reasoned selection of reactive power compensation installations for existing ore reduction electric furnaces. With full compensation of the reactive power (transverse and longitudinal), the arc burning mode of the ore reduction furnace becomes intermittent.
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, Yevheniia
ENG: 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.
Investigation of Electromagnetic Parameters and Electromechanical Characteristics of a DC Machine Based on the Finite Element Method
(Видавничий дім «Гельветика», 2024) Kachura, Oleksii V.; Nikolenko, Anatolii V.; Kovalenko, Viktor; Kuznetsov, Vitaliy V.; Syanov, Alexander; Tsyplenkov, Dmytro; Kolychev, Sergei V.; Gurin, Yevgen
ENG: The verification calculation of the serial machine of direct current (DCM) MUN-2 with a modified excitation system based on the finite element method (FEM), which allows to investigate the characteristics and electromagnetic parameters of DCM taking into account new design solutions in static, quasi-static and dynamic modes of operation. The finite element model of the DCM can be combined with the chain model of the power supply based on the joint solution of the field and circuit equations, which makes it possible to investigate the characteristics of the engine in various modes when the anchor winding supplies signals of any shape. Based on the obtained results, the verification calculation of the DCM MUN-2 with a modified excitation system based on MSE allows the study of the characteristics and electromagnetic parameters of the DCM, considering new constructive solutions in dynamic modes of operation. The resulting DCM field model can be combined with the power source circuit model based on the joint solution of the field and circuit equations, which makes it possible to study the characteristics of the motor in different modes when feeding the armature winding with signals of any shape. The work established that the motor reaches the maximum rotation speed after 300 ms at a voltage of 120 V on the armature winding. At the same time, there is a surge in the starting current of the armature up to 2.0 A with subsequent stabilization at the level of 0.08 A. The starting torque reaches 1.2 Nm. The MUN-2 reaches the nominal rotation frequency at the nominal load, accompanied by an increase in the armature winding current to 0.7 A. During the operation of the motor, an electromotive force is induced in the armature winding, which, when the motor reaches the nominal rotation speed, stabilizes at the level of 20 V and has a peak character. Maxwell’s system of electromagnetic fields and analytical and mathematical methods for partial differential equations are used to solve the problems. The finite element method is used to solve the differential equations of the magnetic field.