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Research of the Ore Reducing Furnaces Electrical Modes for Ferronicel Production
(Ukrainian State University of Science and Technologies, Dnipro, 2025) Shevchenko, D. V.; Ovcharuk, Anatolii N.; Gladkih, V. A.; Bezugliy, Anatolii V.; Nikolenko, Anatolii V.
ENG: The paper presents the results of a study of the electrical modes of ferronickel furnaces OTF-1 and OTF-2 at the Pobuzhsky ferronickel plant. It was found that the furnaces operate in arcless mode. An asymmetrical voltage mode is observed: electrode casing - under, which indicates an unbalanced mode of the furnace. As a result of measurements, a significant transfer of power was detected in the area of the electrical circuit of the 4th, 5th, 6th electrodes. An analysis of the electrical mode of a 48 MVA round ferronickel furnace in the city of Hua-Hua (China) showed that the use of a furnace transformer without a voltage booster and an autotransformer makes it possible to provide the necessary electrical mode of ferronickel furnaces. An analysis of the electrical mode of a 90 MVA round ferronickel furnace in Guatemala showed the possibility of operating these furnaces in a combined mode, i.e. in the presence of an electric arc, which is controlled by the resistance of the electrodes and the power ratio in the electric arc and slag.
Контроль та покращення якості електроенергії в мережах промислових підприємств
(Український державний університет науки і технологій, ННІ ≪Інститут промислових та бізнес технологій≫, ІВК ≪Системні технології≫, Дніпро, 2025) Стьопкін, Василь Володимирович; Радченко, Віталій Васильович; Ровенський, Олег Олександрович; Єрофєєва, Аліна Анатоліївна; Піліпенко, В'ячеслав Олександрович; Прихно, Валерія Леонідівна
UKR: Метою роботи Метою дослідження є комплексний аналіз проблем якості електроенергії (PQ) в мережах промислових підприємств, а також розробка та систематизація методів контролю, діагностики і покращення основних PQ-параметрів, таких як гармонічні спотворення, флікер, провали напруги, несиметрія фаз і реактивна потужність. Методика. У роботі використано поєднання теоретичного аналізу, огляду стандартів (IEC 61000-4-30, EN 50160, IEEE 519) та практичного досвіду впровадження сучасних цифрових аналізаторів PQ. Проаналізовано застосування фільтрів, компенсаторів та інтелектуальних систем, зокрема DVR, STATCOM, гібридних активних фільтрів, а також машинного навчання для класифікації PQ-подій. Результати. У ході дослідження охарактеризовано основні показники PQ, наведено методи їх вимірювання, діагностики та компенсації. Представлено приклади впровадження технічних рішень для покращення якості енергії, зокрема: пасивні та активні фільтри гармонік, SVC і STATCOM для боротьби з флікером, методи зниження несиметрії та захисту від короткочасних порушень живлення. Наукова новизна. Запропоновано концепцію розподіленої компенсації якості електроенергії із використанням можливостей смарт-інверторів та зарядних станцій. Розглянуто застосування нейромереж та S-перетворень для ідентифікації джерел збурень у режимі реального часу. Обґрунтовано переваги інтегрованих підходів до локальної та централізованої корекції PQ. Практичне значення. Результати можуть бути використані інженерами з енергоменеджменту та персоналом підприємств для побудови систем моніторингу, захисту критичного обладнання та підвищення енергоефективності. Запропоновані рішення зменшують аварійність, втрати енергії та витрати на обслуговування, забезпечуючи відповідність сучасним стандартам сталого розвитку.
Modeling of Wind Speed Distribution in Urban Environment for the Application of Wind Energy Potential Estimation: Case Study
(UIKTEN, Serbia, 2025) Mykhailenko, Oleksii; Karabut, Nadezhda; Doskoch, Volodymyr; Burtseva, Olena; Kuznetsov, Vitaliy V.; Tsvirkun, Sergij; Kolomits, Hanna
ENG: When designing wind farms, the first stage is always an assessment of the target area wind energy potential. It is necessary to have a mathematical description of the wind speeds occurrence probability at the wind turbines potential location to do this. An analysis of relevant studies shows that the most effective approach to obtaining such dependencies is when the wind speed is taken as a random variable. In this case, wind speed distribution in the target area can be modeled using continuous probability distributions. This article is devoted to determining the typical probability distribution models for representing wind conditions in certain areas of the Dnipropetrovsk oblast (Ukraine), which can be used to estimate expected level of power generation by wind power plants. To obtain the data, a series of wind speed measurements were taken at three locations throughout the year. After that, frequency wind speed distributions with ranges of 0.2, 0.5, and 0.8 m/s were created from the obtained dataset and then approximated by continuous probability distributions. Frequency distributions were modeled by Weibull, Rayleigh, Nakagami, gamma, normal, log-normal, generalized extreme value, Birnbaum-Saunders, Wald and Rice continuous distributions. To determine the parameters of each type probability distribution, which is the most relevant to the frequency distribution, the maximum likelihood estimation method was used. To assess the accuracy of the models, the Pearson test, coefficient of determination and normalized root mean square deviation are used. The probability distributions quality is also evaluated graphically using Q-Q plots. The best fit to wind speed frequency distributions demonstrated by the Weibull probability distributions. A slightly lower accuracy was provided by the normal, Rice and Nakagami distributions than Weibull distribution. But in some cases, these distributions have even smaller error than the last one. Therefore, after detailed analysis and validation, they can also be used. The Rayleigh distribution had the worst accuracy, the Pearson test for it rejected the null hypothesis that the probability distributions correspond to the frequency distributions at all three locations. Additionally, the effect of the frequency distribution wind speed grouping range on the quality of maximum likelihood estimation of continuous distribution parameters was analyzed. It showed that the approximation accuracy decreases with increasing range.
Investigation of Electromagnetic Parameters and Electromechanical Characteristics of a DC Machine Based on the Finite Element Method
(Видавничий дім «Гельветика», 2024) Kachura, Oleksii; Nikolenko, Anatolii V.; Kovalenko, Viktor; Kuznetsov, Vitaliy V.; Syanov, Alexander; Tsyplenkov, Dmytro; Kolychev, Sergei; 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.
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.
Аналіз стану термічно резервної зони доменної печі при використанні в шихті рудовугільних композицій
(Український державний університет науки і технологій, ННІ ≪Інститут промислових та бізнес технологій≫, ІВК ≪Системні технології≫, Дніпро, 2024) Ванюков, Антон Андрійович; Камкіна, Людмила Володимирівна; Іващенко, Валерій Петрович; Мяновська, Яна Валеріївна; Сазонов, П. О.
UKR: Розглянуто виникнення та існування зон у доменній печі, обумовлене закономірностями теплообміну. У середній зоні доменної печі температура потоку газу, що виходить, залишається відносно постійною і в ній не відбуваються хімічні процеси. Це "термічно резервна зона", верхня частина цієї зони – "хімічно резервна зона" представлена вюститом, який не відновлюється. Резерв цієї зони – утворення газової фази. При добавках у шихту рудовугільних композицій відбувається відновлення оксидів заліза (t=1000 °C) за реакцією Fe2O3+C=Fe3O4+CO2 та газифікації вуглецю СО2+С=2СО (Реакція Будуара). Газова фаза (СО), що утворюється, інтенсивно відновлює оксиди заліза. Композити для доменної плавки виробляються із суміші доменних шламів із добавками цементу. Суміш переробляється рудовугільні котуни або брикети. Доменна плавка на металургійних заводах України, Південної Кореї, Японії показала, що використання рудовугільних композитів є ефективною добавкою в шихту доменної плавки для зниження витрати коксу. В основі ефекту рудовугільного композиту лежить теорія "Тісного контакту" (Coupling Phenomenom) між вуглецевими і залізовмісними матеріалами в окатиші-композиті. Їхня взаємодія відбувається, як показали дослідження, при температурах 250-420°C в атмосфері СО. З урахуванням реакції Будуара температура в термічно резервній зоні доменної печі знижується на 80-200°C. Таким чином, у хімічно резервній зоні – відновлення в'юститу відбувається не при 1000°C, а при 920-800°C і вона зміщується ближче до зон формування чавуну і шлаку. У статті проаналізовано термограми у доменній печі з урахуванням рудовугільних композитів. Хімічно резервна зона розташовується у середині шахти (від поверхні шлаку) 11,2 м. Зі збільшенням витрати композиту в шихті (30%) становище резервної зони знижується з 11,2 до 6,2 м. Ширина між термограмами 1200°C –1400°C є характерною зоною когезії, зі збільшенням витрат композиту знижується з 2,1 м т (без завантаження композиту) до 0,9 м при витраті композиту 30%.
Mathematical Modelling of Induction Motors Taking into Account Design-Parameter Asymmetry
(Lithuanian Academy of Sciences, Vilnius, Lithuania, 2024) Kurliak, Petro; Tytiuk, Valerii; Chornyi, Oleksii; Kuznetsov, Vitaliy V.; Artemenko, Artem; Chorna, Olha
ENG: Due to their numerous technical and economic advantages, induction machines (IM) with squirrel-cage rotors are important components of many industrial processes. Their reliability, durability, and ease of operation make them indispensable in various industries, ensuring stable and efficient equipment performance. However, to minimise the risk of costly production failures caused by sudden stoppages, it is important to implement effective diagnostic and monitoring methods. The most common type of fault in squirrel-cage induction motors is the breakage of cage bars and end ring segments, particularly in motors with high inertia loads and frequent stops and starts. Regular maintenance and the implementation of modern control systems in the industry will help ensure the reliable and uninterrupted operation of these machines. In the technical literature, various diagnostic methods have been proposed. Some are based on analysing data collected from the induction motor (IM), detecting characteristic perturbations that indicate faults in the machine. Other methods involve comparing the data obtained from the actual induction motor with its digital model. It is clear that accurate and adequate IM models are necessary for the development and optimisation of fault diagnosis methods. This paper focuses on developing a mathematical model of an induction motor (IM) in a stator-fixed coordinate system, where the squirrel-cage rotor of the IM is represented as a multiphase, symmetrically distributed winding system in space. The adequacy of the obtained model is demonstrated. The developed model allows for the analysis of various types of asymmetries in both stator and rotor of squirrel-cage induction motors.
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.
Principles of Constructing Equivalent Circuits for Nonlinear Electrochemical Elements: Analysis and Experimental Parameter Determination
(Український державний університет науки і технологій, ННІ ≪Інститут промислових та бізнес технологій≫, ІВК ≪Системні технології≫, Дніпро, 2024) Bondar, Oleh I.; Nikolenko, Anatolii V.; Kovalenko, Viktor; Kitaev, Oleh; Stepanenko, Oleh; Siversky, Serhii; Sprysa, Vasyl
ENG: The paper proposes a generalized scheme for replacing the electrolyzer for the deposition of metal coatings. As nonlinear elements of the specified scheme, the dependences of the partial currents of metal dissolution and deposition on the near-anode or near-cathode voltage drop are considered, respectively. The possibility of applying certain simplifications in the general scheme, depending on the peculiarities of the deposition process of one or another metal, was also analyzed. At the same time, the general structure of approximating expressions is proposed and the approximation coefficients for individual nonlinear electrochemical elements are determined. The specified expressions differ from the previously known ones in that their structure is suitable for obtaining the general regularities of electromagnetic processes that take place in systems of pulse electrodeposition of metals in an explicit form.
Specific Heat Capacities as Key Factors for the Calcination of Carbonaceous Materials
(Slovnaft VURUP a.s, Slovakia, 2023) Bezugly, Volodymyr; Koveria, Andrii; Bezugly, Аnatolii V.
ENG: The development of new and improvement of existing technologies for the calcination of carbonaceous materials requires their specific heat capacities, which are key factors of the process. Analytical temperature dependences of specific heat capacities of carbonaceous materials were established in the study, considering material transformations and determination errors when they are heated to a temperature of 1800oC and then cooled to a temperature of 20oC. The minimum necessary temperatures of the calcination process and their duration are also determined, which are guaranteed to ensure the required quality of the products in conditions of dispersion of the properties of the raw materials. The new dependencies facilitate for more reliable mathematical modeling of the calcination process of carbonaceous materials by taking into account material transformations and the direction of temperature change and will ensure a more rational development of calcination furnaces and the process. Additionally, the determined theoretical minimum possible specific energy consumption allows for estimating the energy efficiency of the calcination process.
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.
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.
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.
On the Feasibility of Choosing Means of an Asynchronous Motor Protection in Industrial Conditions
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2023) Tryputen, Mykola; Kuznetsov, Vitaliy V.
ENG: The article is devoted to the urgent problem of choosing the means of protection of asynchronous motors (AM) operating in the shop electric networks of industrial enterprises with low-quality electricity. The well-known energy-economic model of an induction motor is presented in the form of a predicate disjunction, to which we apply the pattern recognition algorithm for making decisions. The main advantage of the predicate model is openness and the possibility of accumulating knowledge about the operating modes of electromechanical equipment. The practical implementation of training, adaptation, minimization of the predicate model and the search on its basis for the best option for protecting an asynchronous motor in high-level algorithmic languages involves the processing of large amounts of data. It is shown that elements of predicate equations can be represented as a relational data model and use operations - algebras for its transformations. The transformation procedures are easily integrated into the information and software structures of the automated enterprise management structure, which use database management systems oriented to relational models.
Minimization of Power Fluctuations of Wind Power Plants when Constructed in Exclusion Zones of Enterprises
(Dnipro University of Technology, Dnipro, Ukraine, 2023) Kachan, Yu. G.; Kuznetsov, Vitalii V.; Shram, O. A.
ENG: Purpose. Development of a methodology for selecting types and quantities of wind turbines built in exclusion zones of industrial enterprises to minimize fluctuations in the power generated by them and increase the efficiency of their use. Methodology. The work used methods of synthesis of systems, computer modeling in the calculation of the optimal number of different types of wind turbines, methods of combinatorics. Findings. The developed method for designing wind power plants built in the exclusion zones of enterprises allows determining the required number of different types of wind turbines with different capacities and nominal values relative to the wind speed, which will provide the necessary generated power with minimal fluctuations. This makes it possible to notably reduce the capacity required for the accumulation of excess generation and to significantly reduce the cost of implementing wind turbines. Originality. The work proposes a methodology for designing wind power plants based on various wind turbines, taking into account their type, power and wind characteristics of the area where the wind power plant is being built. It has been found that the coefficient of fluctuation of the power generated by the wind power plant built on the same type of wind turbines does not depend on the capacity of such a station, nor on the number of wind turbines used, but only on the type of the latter and the wind characteristics of the area where it was built. Practical value. Wind power plants used at enterprises have significant daily and annual fluctuations in the power generated by them. The proposed approach allows reducing fluctuations of power generated by the station, as well as increasing the amount of electricity generation in comparison with the use of the same type of wind turbines.
Mathematical Model of the Closed-Loop System of Excavator Bucket Positioning
(Dnipro University of Technology, Dnipro, Ukraine, 2023) Tytiuk, V.; Chornyi, O.; Mrachkovskyi, D.; Tryputen, S.; Tryputen, M.; Kuznetsov, Vitalii V.
ENG: Purpose. Study on energy consumption of mechatronic systems of mining excavators during the full production cycle, development of energy efficiency criterium for the production cycle of mining excavators, which ensures an increase in the technical and economic indicators of the operation of powerful mining equipment. Methodology. Mathematical modeling of electro-mechanical system of “front shovel” excavator, determination indicators of the production cycle, development of the criterion of energy efficiency of the mining excavator’s operating cycle taking into account the theory of technical systems efficiency. Findings. A mathematical model of a complete electro-mechanical system of an excavator with “generator-engine” electric drive has been developed, which includes a model of the mechanical part of the excavator. The closed-loop bucket positioning system makes it possible to implement various movement trajectories during the operating cycle. Numerical characteristics of energy consumption and duration for various movement trajectories of the working bodies of the excavator are obtained. A new criterion of energy efficiency of mechatronic systems of mining excavators is proposed. Originality. For the first time, a mathematical model has been proposed of an integral electro-mechanical system of an excavator according to the “front shovel” scheme, which includes models of electric drives of all mechanisms and a synchronous drive motor, as well as a model of the mechanical part of the excavator; this makes it possible to increase the accuracy of determining the excavator’s energy consumption and the operating cycle time. A criterion of energy efficiency is proposed, which takes into account the amount of resource costs, the overall result and the duration of the excavator’s operating cycle. Practical value. A mathematical model of the electromechanical system of an excavator with an electric drive according to the “generator-motor” system has been developed, which, taking into account the solution of the direct and inverse problems of the kinematics of the mechanical system of the excavator, makes it possible to compare parameters of various trajectories of movement of the excavator. The implementation of a closed system for positioning the excavator bucket in three-dimensional space was proposed, which creates conditions for increasing the level of automation of mining excavators. A criterion of the energy efficiency of the excavator’s technological cycle is proposed, which takes into account resource costs and the technological cycle duration.
Mathematical Model of a Three-Phase Induction Motor with Asymmetrical Twelve-Zone Stator Windings
(IEEE, 2022) Tytiuk, Valerii; Chornyi, Oleksii; Busher, Victor; Siverskaya, Tatyana; Baranovskaya, Mila; Kuznetsov, Vitalii V.
ENG: The paper proposes a mathematical model of a three-phase induction motor with an asymmetrical twelve-zone winding of stator with parallel connection of subwindings. The mathematical model was developed using the theory of generalized electromechanical converter and contains equations of electrical equilibrium of six stator windings and three rotor windings. The equations for calculating the electromagnetic moment and the equations of motion of the induction motor with an asymmetrical twelve-zone stator winding rotor were obtained. The developed mathematical model in the form of cell-matrix equations has been implemented in MATLAB/Simulink.
Nonlinear Analysis of Bifurcatory Properties of Mathematical Model of Subpopulation Dynamics in the Case of a Single Niche for Subpopulation
(IEEE, 2022) Kuzenkov, Olexandr; Busher, Victor; Chornyi, Oleksii; Nikolenko, Anatoliy V.; Kuznetsov, Vitaliy V.; Savvin, Oleksandr V.
ENG: The article is devoted to the use of mathematical models of the dynamics of heterogeneous populations, and computer simulation based on the above models allows to identify general trends in subpopulations, predict the state of the system and obtain results on possible consequences of artificial intervention. Also, the use of mathematical models can predict the spread of genetic anomalies. The authors propose a model of subpopulation dynamics with a logistic function as a basic one. It is concluded that the system-wide dynamics of subpopulation processes depends not only on the reproductive potential of subpopulations, but also on the intrasystemic dynamics that objectively occur in such systems. The adequacy of the proposed mathematical model is proved. © 2022 IEEE.
Methods of Pulse Width Modulation in Cascaded High Voltage Frequency Converters
(IEEE, 2022) Busher, Victor; Chornyi, Oleksii; Tytiuk, Valerii; Glazeva, Oksana; Rozlutskyi, Oleksandr; Kuznetsov, Vitaliy V.
ENG: Purpose. The aim of this work is to compare the effectiveness of various methods for correcting cell failures in cascade high voltage frequency converters. These methods provide the smallest voltage drop on the motor, the least loads and oscillation of electromagnetic torque in an accident modes, and evaluate the effectiveness of pulse width modulation (PWM) methods with the injection of third harmonic and space-vector PWM in normal and emergency modes. Methodology. We use mathematical and geometrical interpretation of all analysed methods - Sinusoidal PWM (SPWM), Balanced sinusoidal PWM (BSPWM), Balanced PWM with injected 3rd harmonic (THPWM) and Balanced Space Vector PWM (SVPWM). Results. The method of balancing the phase-to-phase voltages by to such a shift of the zero point and rotation of the phase vectors, in which the amplitude of the phase-to-phase voltage decreases to the minimum possible value. Injection of the 3rd harmonic allows you to further increase the utilisation factor of power supplies in terms of voltage. But the violation of the symmetry of the phase voltages leads to the need to reduce the voltage amplitude to exclude saturation of the power supplies, which reduces this coefficient compared to the theoretically possible 15.6%. A distinctive feature of the method of balanced Space Vector PWM is that the amplitude of the 1st harmonic is always greater than the radius of the circle by 15.6%. Comparison of methods of space vector PWM (SVPWM), balancing of phase-to-phase voltage with the injection of the 3rd harmonic (THPWM) with sinusoidal PWM shows that SVPWM is the best method. Despite the more complex mathematical software for the implementation of this method, it provides the best performance in all considered emergency modes of 3...6 cascade converters. The Table of indicators for all methods are presented in the article. The use of a balanced SVPWM in combination with field oriented control makes it possible to obtain an electric drive in which, in the event of an accident, there are practically no shock mechanical and electromagnetic processes. After damage of cells the currents, electromagnetic torque and motor speed change along the required trajectory. © 2022 IEEE.
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.

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