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E-Journal N4(60)2023

"PROBLEMS of the REGIONAL ENERGETICS (https://doi.org/10.52254/1857-0070.2023.4-60)"

CONTENTS

1	Improving the Efficiency of Electric Rolling Stock Operation Through the Use of Adaptive Filtering Methods for High Harmonic Current Components in Traction Drive Systems Authors: Goolak S. State University of Infrastructure and Technologies Kyiv, Ukraine
	Abstract: The aim of this work is to investigate the efficiency of various adaptive filtering methods for higher harmonic components of stator currents in a vector-controlled traction drive system to improve the operation efficiency of electric rolling stock. The set goal was achieved by implementing an adaptive filtering block into the basic vector control system, which sequentially employs various adaptive filtering methods. The first harmonic component of stator currents was proposed to be used as the desired signal. An algorithm for determining the first harmonic component under conditions of varying supply voltage frequency was developed. Based on the simulation results, filtration efficiency metrics were established, indicating that the Wiener filter is the most effective for filtering higher harmonic components of stator currents. The most significant results include the algorithm for determining the first harmonic component of the stator phase current and the determination of an adaptive filtering algorithm with the highest convergence rate. The importance of these results lies in identifying the most effective adaptive filtering algorithm for traction drive operation, taking into account the operating modes of electric rolling stock. This will help reduce losses from higher harmonic components in the traction drive and, consequently, increase its energy efficiency.
	Keywords: operational efficiency, energy efficiency, vector control, higher harmonic components, adaptive filtering, electric rolling stock. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.01
2	Electromagnetic Shielding of Two-Circuit Overhead Power Lines Magnetic Field Authors: Kuznetsov B.I., Nikitina T.B., Bovdui I.V., Voloshko O.V., Chunikhin K.V., Dobrodeyev P.N. Anatolii Pidhornyi Institute of Mechanical Engineering Problems of the National Academy of Sciences of Ukraine Kharkiv, Ukraine
	Abstract: The purpose of the work is to design an electromagnetic shield to reduce the level of the magnet-ic field generated by double-circuit overhead power lines to increase the shielding efficiency of the initial magnetic field in residential buildings to the level of sanitary standards and reduce the system's sensitivity to changes in system parameters. To achieve this goal, the structure of the electromagnetic shield is determined, which consists of a single-circuit active and multi-circuit passive parts and is characterized by an increased efficiency of reducing the magnetic field of industrial frequency. The design of an electromagnetic shield is reduced to solving a minimax vector optimization problem, in which the vector objective function is calculated based on solu-tions of Maxwell's equations in a quasi-stationary approximation using the COMSOL Multiphys-ics software package. The solution of the minimax vector optimization problem is calculated on the basis of optimization algorithms by a multiswarm of particles from Pareto-optimal solutions. The most important results are theoretical and experimental studies of the effectiveness of the designed electromagnetic shield of the magnetic field generated by double-circuit overhead power lines. The significance of the results obtained lies in the fact that practical recommenda-tions are given on the reasonable choice of the spatial arrangement of the contours of the multi-circuit passive screen and the shielding winding of the robust system of electromagnetic shield-ing of the magnetic field generated by double-circuit overhead power lines. The possibility of reducing the induction of the initial magnetic field to the level of sanitary standards has been shown as well.
	Keywords: two-circuit overhead power lines, magnetic field, electromagnetic shielding, theoretical and experimental studies. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.02
3	Segmentation of Images Used in Unmanned Aerial Vehicles Navigation Systems Authors: Yeromina N.1, Udovenko S.2, Tiurina V. 3 Boychenko O.4, Breus P.5, Onishchenko Yu6., Gnusov Yu. 6, Svitlychnyi V.6 1 Kharkiv National University of Radio Electronics, Kharkiv, Ukraine 2 Simon Kuznets Kharkiv National University of Economics, Kharkiv, Ukraine 3 Kharkiv National Air Force University named after Ivan Kozhedub, Kharkiv, Ukraine 4 State Scientific Research Institute of Armament and Military Equipment Testing and Certification, Cherkasy, Ukraine 5 Flight Academy of the National Aviation University, Kropyvnytskyi, Ukraine 6 Kharkiv National University of Internal Affairs, Kharkiv, Ukraine
	Abstract: . The paper presents the results of the study of a two-stage procedure for selecting a reference object in the current image formed by a correlation-extreme system used for autonomous navigation of unmanned aerial vehicles. The aim of this paper is to theoretically evaluate the probability of selecting low-dimensional low-contrast objects in the segmented current image according to the proposed two-stage procedure. To achieve this goal, the problem of segmentation of images of the sighting surface and subsequent selection of the reference object in the presence of heterogeneous objects differing in brightness and area characteristics is solved. The most significant result is the justification of application of two-stage procedure of selection of the reference object in the current image by brightness and area parameters using the set thresholds. The significance of the obtained results consists in establishing the dependence of the probability of correct selection of the reference object on the noise level of the current images. It is shown that the probability of correct selection of the object in the image is a function of the threshold value and can be maximised by choosing its value. This approach allows to consider the influence of various factors leading to image noise on the quality of images formed by the navigation system. It is shown that when noise distorts more than 31% of the image pixels, the proposed two-stage procedure allows to ensure the selection of the reference object in the image with a probability not lower than 0.9.
	Keywords: correlation-extremal navigation system, unmanned aerial vehicles, information features, image segmentation method, decision function. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.03
4	High Temperature Superconducting Transformer Operating at an Increased Frequency of Alternating Current Authors: Manusov V.Z., Galeev R.G. Siberian State University of Water Transport, Novosibirsk, Russian Federation
	Abstract: The study's aim is to substantiate and employ materials with high technical characteristics for the active elements of a transformer, particularly in the context of increased operating frequencies. To accomplish this objective, the following tasks were addressed: An analysis and synthesis of the properties of a magnetic core composed of amorphous iron and superconducting windings in a high-temperature superconducting transformer (HST) were conducted. Dependencies and graphs illustrating the impact of frequency increase on heat losses related to hysteresis and eddy currents were derived. These losses occur within the magnetic circuit. The study also demonstrates the relationship between reducing size and weight parameters and material consumption of windings in high-temperature superconducting (HST) tapes. Current densities in these tapes can reach up to 500 A/mm². The most noteworthy outcome, taking advantage of superconductivity in the HST, is that HST acts as an ideal diamagnetic material. Additionally, the windings exhibit high electrical conductivity. This resolves issues related to current displacement to the conductor's surface, commonly known as the "skin effect," and effectively addresses concerns about increased resistance in transformers and electrical machines. The absence of the skin effect in HST conductors has been rigorously demonstrated using Bessel functions. The significance of these results is in enhancing the efficiency of transformers operating at high frequencies. This is achieved by synthesizing the properties of the transformer's active elements, which include an amorphous iron magnetic core, HST windings, and a dielectric medium utilizing liquid nitrogen.
	Keywords: increased frequency, magnetic circuit, energy efficiency, HTS transformer, skin effect. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.04
5	Theoretical Examination of the Volume Concentration and Nanoparticles Density Influence on the Convective Heat Transfer Enhancement of Nanofluid in 2D Cavity Including the Square Heater Authors: Oulahou Y.1, Elguennouni Y.1, Hssikou M.2, Baliti J.2, Alaoui M.1 1Department of Mechanical-Energetic, Faculty of sciences, Moulay Ismail University, Meknes, Morocco, 2LRPSI, Polydisciplinary Faculty, University of Sultan Moulay Slimane, Beni Mellal, Morocco.
	Abstract: Nanofluid is one of the solutions of heat transfer, which can apply in devices fields as nuclear power, Nano-electronics systems, and solar fluid heating. In this work, the natural convection of Cu-water nanofluid is examined using the Lattice Boltzmann Method (LBM) as a mesoscopic approach. The main objectives of this work are to study the performance and pattern of Cu-water nanofluid and to demonstrate that the nanofluids behave differently while improving their energy transfer compared to pure fluids. The set goal was achieved by solving the tasks: based on the streamlines and isotherms profiles to demonstrate how the convection process and temperature gradients improve. Also, conducting study on heat transfer of nanofluid by calculate the Nusselt number. Depending on the nanoparticle volume percentage , the Grashof number , and the hot obstacle have a significant impact on the convection flow and rate of heat transfer. The most important result is the enhancement of heat transfer with the increasing of volume fraction for a particular Grashof number, also it improves with the rising of Grashof number for a particular nanoparticles volume fraction. Therefore, the aspect ratios of the enclosure have played a significant part in Nusselt number variation. In addition, we found that the Nusselt number is higher in the case of cavity without hot obstacle more than for cavity with hot obstacle, so the heat transfer improves in the case of cavity without hot obstacle. The significance of the obtained results consists that the nanofluid is one of the ways to improve heat transfer due to its specific characteristics and properties.
	Keywords: convecție naturală, metoda Boltzmann latice, nanofluid, transfer de căldură, număr Grashof. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.05
6	Assessment of the Slagging Tendency in Power Plant Boiler Furnaces Depending on the Physical-Chemical Characteristics of Ash and Coal Authors: Chernov S.L., Prokhorov V.B., Pay A.V., Aparov V.D. National Research University "Moscow Power Engineering Institute", Moscow, Russian Federation
	Abstract: The purpose of the work is to select replacing design coal possible options for low slagging potential reasons in the furnace and on adjacent heating surfaces. Solved problems: the main slagging indices (SI) are summarized, based on considering the two main parameters of the formation of ash deposits, namely viscosity and fusibility. An analysis of existing methods for assessing slagging processes of heating surfaces in steam power boilers was carried out. The scientific goal is achieved by the proposed method of ranking coals according to their slagging tendency on power boiler heating surfaces based on their physicochemical properties. The methodology is based on the slagging potential dependence of the fusibility and viscosity ash characteristics, considering the ratio of the ash percentage content to the heating value of coal. The most important result is ranking of 28 coals of various grades (subbituminous, bituminous, anthracite) burned at Russian power plants according to their tendency to form ash deposits on the furnaces of power boilers. The significance of the results obtained lies in the identification of two coal deposits, subbituminous Irsha-Borodinsky and Berezovsky in Easten Siberia and Kuznetsky bituminous in Western Siberia, which are universal during the transition to burning non-design fuel from the slagging potential point of view. The dependences of the change in ash viscosity and SI on the and ratios in ash for Irsha-Borodinsky and Moscow region coals were under consideration. It was concluded that the value of the SI is directly proportional to the load ash content and could differ more by an order of magnitude for different coals.
	Keywords: power plant, power boilers, solid fuel, coal, slagging, ash fusibility, ash viscosity. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.06
7	Increasing the Production of Electrical and Thermal Energy in Biogas Plants through the Optimal Addition of Agricultural Waste Authors: Polishchuk V.М., Shvorov S.А., Pasichnik N.A., Davidenko T.S., Valiev Т.О., Dvornyk Ye.O. National University of Life and Environmental Sciences of Ukraine, Kyiv, Ukrai
	Abstract: The aim of the work is to increase the yield of biogas, and, accordingly, the generation of electrical and thermal energy in biogas plants by optimally adding agricultural production waste to cattle manure. To achieve the goals set, the following tasks were solved: the yield of biogas from cattle manure was determined with the addition of various volumes of organic waste during periodic loading of the digester; on the basis of the experimental data obtained, the unimodality interval was found for the maximum yield of biogas during the fermentation of cattle pus with the addition of organic waste; Using the dichotomy method, the optimal dosage volume of various types of organic wastes into the substrate for quasi-continuous loading of the digester was calculated. Experimental studies were carried out on a biogas laboratory plant with a useful volume of 30 liters in a mesophilic mode. The most significant result is the determination, using the dichotomy method, of the optimal volumes of organate, starch, flour, whey, wastewater from wineries, crude glycerin, fuse, soap stock and molasses to manure pus to increase the biogas yield. As a result of the research, the optimal dosage formulation of various types of organic waste was substantiated to intensify the fermentation of cattle manure. The significance of the research results lies in the fact that with the optimal addition of these cosubstrates to the digester using special dispensers, the biogas yield increases from 1.4 l/h. kg of dry organic matter and above.
	Keywords: organic waste, substrate, dry organic matter, biogas plant, digester, biogas, cattle manure, methane fermentation. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.07
8	Universal Method for Detecting Violations in the Integrity of a Digital Image Based on Analysis of Blocks of its Matrix Authors: Bobok I., Kobozeva A. Odesа Polytechnic National University Odesa, Ukraine
	Abstract: The requirement to provide the content expertise (particularly digital video) in real time is be-coming critical. Thus, the aim of the work is to increase the efficiency of identifying the fact of violation of image integrity by developing a universal expert method with low computational complexity. This aim was achieved by using a new approach developed by the authors earlier that based on the properties of the dependence of the frequency index of the singular vector of the image matrix on its number, adapted for the case of a block organization of expertise. The most important theoretical result of the work is the higher rate of growth of the linear approxi-mation of the dependence of the block-average values of the frequency indexes of singular vec-tors on its number, which was established for the original content, as compared to the non-original content. The significance of the obtained results is that the developed expert method, being a block one, has insignificant computational complexity – operations for an image matrix, which makes it promising for working with digital content, in particular with vid-eo, in real time. At the same time, the algorithmic implementation of the method made it possible to increase the efficiency of detecting violations of image integrity by reducing type I errors by 2% compared to the best analogue; type II errors remained at the same level. The versatility of the method is confirmed by its high efficiency regardless of the specifics of the perturbation ef-fect, including in conditions of minor disturbances.
	Keywords: digital image, integrity violation, singular vector, frequency index of singular vector, integrity expertise. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.08
9	The Influence of Previous Treatment of Wheat Straw from Bales on the Intensity of Biogas Outlet Authors: Zablodskiy M.1, Klendiy P.2, Shvorov S. 1, Trokhaniak V. 1, Dudar O.3 1National University of Life and Environmental Sciences of Ukraine, Kyiv, Ukraine 2 Separated subdivision "Berezhany Agrotechnical Institute" National University of Life and Environmental Sciences of Ukraine, Berezhany, Ukraine 3Separated structural subdivision “Berezhany professional college of National University of Life and Environmental Sciences of Ukraine” Berezhany, Ukraine
	Abstract: The purpose of the research is the experimental determination of the effect of preliminary mechanical and additional magnetic treatment of wheat straw from bales on the intensity of biogas output. This goal is achieved by solving the following problems: determining the physical-chemical properties and component composition of winter wheat straw from packs; obtaining chopped straw by grinding on a laboratory grinder to a fraction of 5–25 mm in length; processing soaked straw in water in an extruder to form 15 pre-treatment samples; calculation the carbon-nitrogen ratio for mixture of straw of certain pretreatment option and inoculum; determination the specific energy intensity of the extrusion process; conducting fermentation experiments and studies of the biogas output process for 42 days for various options for pre-treatment of winter wheat straw from packs, in particular the option with the simultaneous action of constant magnetic field. The most important results of the research are: experimental proof of the effectiveness of the method of preliminary mechanical-magnetic treatment of winter wheat straw from bales in the production of biogas, which forms a synergetic effect; with a one-time extrusion of straw and treatment with constant magnetic field of 1.8 mT, the biogas output increases, which makes it possible to obtain the same amount of biogas as with 5-fold extrusion, but with energy costs for extrusion reduced by 4.28 times. At the same time, sufficient productivity of the biogas production process is maintained, the lag phase is reduced, and the biomethane output increases by approximately 5.5%. The significance of the obtained results is that the proposed approach to the formation of biogas technology with using mechanical-magnetic processing of wheat straw ensures the intensification of biogas output and an increase in the level of production.
	Keywords: anaerobic fermentation, biogas, wheat straw, magnetic field, energy costs, synergetic effect. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.09
10	Optimizing Electric Vehicle Charging with Moth Flame Control Algorithm of Boost-KY Converter Authors: Santosh D. Gadekar1, M. Murali2 1Research Scholar, Faculty of Electrical Engineering, Medi-Caps University, Indore, MP, India 2Associate Professor, Department of Electrical Engineering at Medi-Caps University, Indore, MP, India
	Abstract: Electric vehicles have assumed a prominent role in future transport system due to the diminishing availability and escalating costs of fossil fuels, coupled with growing concerns about the impact of global warming. The purpose of the work consists in addressing the pressing need for efficient and sustainable solutions in the realm of electric vehicles and renewable energy integration. The tasks solved in the article to achieve the given goal are the following: an improved Boost-KY converter has been introduced to counter the inherent limitation of low PV panel voltage output. This converter effectively mitigates voltage and current ripples, thereby ensuring a stable power supply for EV charging. Additionally, the Moth Flame Optimized Proportional Integral (MFO-PI) controller has been implemented to regulate converter operation, demonstrating exceptional proficiency in mitigating PV output unpredictability. MATLAB simulation is done to validate the proposed system's performance. The most important results are the achievement of impressive maximum efficiency of 96.21% and remarkably low Total Harmonic Distortion (THD) value of 1.04%. The system maintains consistent voltage and current levels for PV panels and EV battery, ensuring dependable energy supply. The significance of the results obtained consists in their potential to revolutionize the intersection of renewable energy integration, electric vehicle (EV) adoption, and sustainable transportation practices.The PV-based EV charging system not only reduces dependence on finite fossil fuel resources but also contributes to environmental preservation, aligning with global efforts to combat climate change. Furthermore, system adheres to stringent requirements of IEEE 519 standards, positioning it as a catalyst for the adoption of clean energy solutions within the future transport system.
	Keywords: PV system, electric vehicle, improved Boost-KY converter, Moth Flame optimized PI controller. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.10
11	Optimization of Operating Modes of CHPPs as a Way to Reduce Greenhouse Gas Emissions Authors: Tatarinova N.V., Suvorov D.M. Vyatka State University Kirov, Russian Federation
	Abstract: The aim of the work is to analyze and evaluate the operating efficiency of CHPPs to develop an optimal operating strategy based on minimizing fuel consumption and greenhouse gas emissions. To achieve this goal, the following tasks were solved: a quantitative assessment of the most ef-fective methods of operating units in typical operating modes was given; dependences of chang-es in the main energy and environmental parameters based on mathematical models of turbine units using real energy characteristics of turbine stages and compartments were constructed; long-term optimization method to exploitation operation of CHPРs to the point of view of reduc-ing greenhouse gas emissions was shown on specific examples. The most significant results are the following: a comprehensive methodology for applying mathematical models for solving the most typical problems for CHPP was used, both from the point of view of saving primary fuel and reducing carbon emissions; the dependences of the influence of operating parameters on the carbon footprint were calculated; it has been established that the specific consumption of equiv-alent fuel and the carbon footprint are reduced when the loads are redistributed between turbine units during the heating period; the advantages of two-stage heating of delivery water over sin-gle-stage heating and sequential loading of turbines of the same type over parallel loading have been determined. The significance of the results obtained lies in their applicability in solving problems of optimizing the operating modes of CHPPs, taking into account the determination of the values of reducing greenhouse gas emissions.
	Keywords: greenhouse gas emissions, carbon footprint, cogeneration, district heating, energy efficiency, CHPP, operating measures. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.11
12	The Energy-Saving Control Criterion for Impact Crushing Machines Authors: Chausov S., Sabo A., Popova I. Dmytro Motornyi Tavria State Agrotechnological University Zaporizhzhia, Ukraine Budko V. National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” Kyiv,Ukraine
	Abstract: . The purpose of the article is to substantiate the use of a new criterion for controlling the grinding technological process to improve the use of electrical energy. The subject of the study is the process of using electrical energy in impact grinding machines. The set goal is achieved by solving the following problems: analyzing the energy of the grinding process, determining the parameters of raw materials and operating modes of the electric drive that affect the efficiency of electrical energy usage. Based on theoretical research, a mathematical model of energy consumption in grinding processes has been developed. Analytical studies of the resulting mathematical model showed the nonlinear extreme nature of the specific energy consumption of the grinding process with changing raw material parameters and operating modes. This creates the prerequisites both for using specific electrical energy costs as a control criterion and for the use a controlled electric drive to achieve maximum energy savings. The most important result is that the operating modes of grinding machines could be established by more efficient use of electrical energy. The significance of the work lies in the fact that by adapting the operating modes of the electric drive to the current parameters of the raw materials and the state of the equipment make possible to reduce the specific electrical energy consumption up to 15% and this is the basis for using a criterion based on specific costs in control systems for technological processes with grinding impact machines. For further application of the obtained results it is necessary to conduct experimental studies to confirm the increase in the efficiency of electrical energy use.
	Keywords: control criterion, energy consumption, mathematical model, adjustable electric drive, grinding. DOI: https://doi.org/10.52254/1857-0070.2023.4-60.12