A research study into using vibration technologies for the transport of granular working medium was carried out. A vibration testing machine, whose calculation model includes a mechanical vibration system having two degrees of freedom with a rigid body on elastic supports, was selected as an object of research. The study involved analysing the variation in the system vibrations by using the structural theory for vibration isolation systems, where a dynamic equivalent represented by a structural diagram of an automatic control system is compared to the initial calculation model. The structural diagram of the system is based on the motion equations in operator form obtained using Lagrange differential equations of the second kind. The Laplace transform was used to transform the initial data for the system of differential motion equations. The paper addresses the characteristics of a new structural and technical solution in the field of vibratory displacement of a granular working medium using the working body of a vibration technological machine, which involves introducing a number of additional weights, levers, springs, and hinges. Here, springs comprise generalised structures containing both elastic elements and vibration dampers. To connect the coordinates of the endpoints in the working body of the vibration technological machine, analytical relations were obtained. It was established that varying the parameters of the elements within the elastic-lever blocks allows the dynamic state of the vibration technological machine to be controlled. In addition, it was shown that the obtained structural diagram helps to derive mathematical expressions for transfer functions, comprising the ratio between the motion coordinates of a technical object and an external force disturbance. On the basis of these expressions, the transfer function for the ratio of the motion coordinates of the vibration technological machine was formulated. A mathematical model of a vibration technological machine was obtained in the form of a transfer function, including a large number of additional elastic and massinertial elements, where the parameters of vibration displacement can be adjusted automatically. The research results will allow the existing technical solutions in the field of technological engineering to be modernised.

The aim is to develop and validate an operational methodology for calculating the force parameters and characteristics of the tool and the process of milling structural materials with end milling cutters. The structural schemes of machining and force models of oblique cutting processes in the modes of axial tool feed and continuous plastic deformation of the processed material were used when developing the method of preliminary calculation of the total axial force working on the cutting edge of end milling cutters. The rotating tool tests were conducted on a Hermle UWF 1202 H 3-axis machining center supplemented with a Kistler piezoelectric dynamometer (model 9272). Authors suggested, developed and tested the preliminary calculation method applied to the force characteristics of the machining process of workpieces by end milling cutters, considering how the energy power of ductile fracture of the machined material affects the process. Contact friction arising on the front and rear surfaces of the cutting tool does not reach the limiting value being subject to the Coulomb – Amonton law, that is, it is estimated by the dependence directly proportional to the normal pressure. After calculations, we defined the materials of the workpiece for milling, that is 45 steel (AISI 1045), and the end two-tooth cutter, uncoated T14K8 alloy, which was used to produce samples. The following milling modes were established: 4 mm boring depth; 50, 100 and 150 m/min cutting speeds; 0.05 and 0.1 mm/rev cutting tool feed. Deviation of the measured values of axial cutting force from the calculated values in the range of changing values of tool feed rate was found to be no more than 11%, and in the range of changing values of cutting speed no more than 15%. The developed calculation and analytical methodology for estimating force parameters of the machining process by end milling cutters provides an increase in the efficiency and reliability of the preliminary prognostic calculation of operating parameters and characteristics of cutting elements of end milling cutters.

The goal of this research is to achieve safe and efficient excavation of coal and rock tunnels with complex geological structures, and to enhance the self-sensing ability of coal and rock cutting equipment and tools. Particle swarm optimization support vector machine is used to identify the cutting state of disc cutting tools. EDEM finite element analysis software is used to analyze cutting process characteristics of the disc cutting tool when used to cut through coal and rock with different compressive strengths. Empirical mode decomposition is used to decompose the load spectrum characteristics; for this purpose, the first-order and seventh-order intrinsic mode functions containing all the feature information of the original signal of the load spectrum are selected. The sample entropy is calculated as the feature input vector. The extracted feature vector is input into the trained support vector machine model and the particle swarm optimization support vector machine model. By extracting the sample entropy of the load spectrum of the disc cutter as the feature vector, the particle swarm optimization support vector model is used to identify the cutting state of the coal and rock. The recognition accuracy of the support vector machine model before and after the improvement is compared and analyzed. The results show that compared to the unoptimized support vector machine, the support vector machine optimized by particle swarm optimization can identify the load spectrum of the coal more quickly and accurately. The recognition accuracy is 96,82%, which verifies the effectiveness of the particle swarm optimization support vector machine model in identifying the load spectrum of the coal and rock disc cutter.

In this work, we develop a conceptual scheme for a robotic complex to perform the installation of parts and their fastening using threaded joints by a robot manipulator. A test bench was created on the basis of a KUKA KR6 R900 industrial robot-manipulator. The robot control software was implemented using the KUKA Robot Language. The proposed actuators are the authors' original development. Two variants of the actuator with screw tightening control are proposed. The first actuating device uses the rotational motion of the robot hand flange to tighten the screws. The second actuating device is equipped, on one side, with a gripper for mounting parts on the product and, on the other side, with a drive tool with a predetermined tightening torque limit. It is shown that both actuating devices ensure a complete cycle of screwing a fastener into a workpiece, from engaging to tightening with the required torque. In the first device, the tightening force is controlled with a strain gauge, the signal from which is processed by an Arduino Mini microcontroller located in a rotating device. The signal is forwarded wirelessly to a stationary controller that sends a stop signal to the robot. It was experimentally established that, due to the presence of the wireless interface, some delay is observed between reaching the torque limit value and stopping the robot rotation during signal transmission. As a result, the value of the actually reached torque may exceed the set value by 60%. In the second device, where torque limitation is based on the current in the drive motor, the absolute error of the torque setting does not exceed 0.8 N·m in the range from 0 to 25 N·m or 3.03% (the error of standard torque wrenches is about 4%). In order to meet the requirements of state-of-the-art cyber-physical production systems, the proposed complex should be complemented with intelligent functions of controlling the process of tightening screw joints on the basis of machine learning methods.

The aim is to develop a method for ensuring the stability and efficiency of the braking process by differentiating the friction linings of brake pads of pad-type disc braking mechanisms. The research applied differentiation of the interaction time of friction pairs and their area, which provides the highest stability indicators of braking mechanisms. The non-standardized bench equipment developed by the author, as well as segmental braking mechanisms providing differentiation of friction pairs by area were used in the study. A method of designing the resultant braking torque was developed using the relationship between the transverse movement of the pads and the developed braking torque of the friction unit. As a result of bench tests, the stability and fluctuation coefficients of the braking torque of the developed pad-type disc brake mechanisms with six pressing elements increased by 12.2 and 34.9%. These values were obtained as compared to serial brake mechanisms equipped with a monopressing mechanism with a single brake pad. The discrepancies between the simulated and obtained data during the bench test on the stability criteria averaged 5.1 and 6.7% for the stability coefficients and braking torque fluctuations for the three brake mechanism variants under consideration, respectively. Differentiation of pressing elements and segmentation of brake pads has the effect of increasing the stability criteria and braking efficiency for pad-type disc brakes. With the analysis of the dependence of the transverse displacement and the developed braking torque, a guaranteed result on the stability criterion and braking torque fluctuations of pad-type disc brakes was modeled. Based on the conducted bench tests, the model developed for obtaining the resultant braking torque for the braking mechanism with segmental pads can be used for designing friction pairs with the set parameters.

This work presents a literature review devoted to increasing the efficiency and quality of managing wind power plants. The analysis focuses on mitigating the adverse effects of wind turbines on the power system and providing system services, such as primary frequency regulation. Nearly 150 scientific publications and reviews, selected from various scientific sources (such as IEEE, Web of Science and Scopus) by the keywords, including “wind power station”, “wind turbine”, “multi-agent control”, “virtual inertia”, “microgrid”, “virtual power plant”, and “frequency control”, were evaluated.

A systematic review methodology of specialised sources was applied, which offers a defined structure for this field of research by categorising articles. The study emphasises the urgency of developing technologies to increase the regulation capacity of a wind power plant, since the low inertia of renewable energy sources leads to a decrease in the stability of power systems, a significant proportion of which accounts for wind power plants. It follows from the literature review that one of the means to increase the stability of such power systems is the creation of virtual inertia for wind power plants. However, due to the limited capacity and control capabilities of each individual wind turbine, the efficiency of introduced virtual inertia may be insufficient, when implemented for individual units. Moreover, it is shown that uncoordinated control can affect the stability of the system. In this review, the specific sources considering coordinated multi-agent control of the virtual inertia for several wind turbines (wind power plants) were analysed. The review concludes that the proposed approach is currently understudied, while the outlined theses can be confirmed by developing the necessary algorithms and analysing the results.

The goal is to determine methods for calculating power losses in a three-phase four-wire low voltage distribution network using measurements of a balance smart meter and consumer smart meters, and to establish the factors influencing the power losses and their allocation among individual network wires, loads, and consumers. The study involved examining three methods for determining power losses for  current measurement snapshot. The first method suggests calculating losses as the difference between the power supplied to the network and the total power consumed. The second method calculates power losses using the contribution method. The third method, which in addition to measurement information requires knowledge of the topology and parameters of the network components, determines power losses based on the results of the state estimation method.  The research proposes an algorithm for transition from a four-wire distribution network modeling to a three-wire one. The algorithm allocates power losses of the neutral wire among the phase wires. The findings indicate that the negative losses in the network with unbalanced phase loads are caused by the presence at the nodes of the least loaded phase of higher voltage than the voltage at the power supply node. The reason for higher losses in phases with minimal load is the uneven allocation of loads in the phases. In addition, the study reveals that the power loss values obtained by the contribution method, i.e. directly from the measurements of smart meters, are closer to the losses determined from the readings of the balance meter and consumer meters, compared to the losses found from the state estimation results. The considered methods for calculation and allocation of power losses are illustrated by an example of a real-world distribution network equipped with smart meters.  The paper demonstrates the examples of allocating total power losses between phase wires and a neutral wire, among phase wires only, and between total loads at phase nodes and individual consumers in phases.

The paper evaluates the generation of electrical energy by a solar power plant equipped with a solar tracking system using the ASHRAE clear-sky method for calculating solar insolation. The mathematical algorithm uses the MathCad system with data export and analysis in Microsoft Excel. Collected over a month and the operation period in 2022–2023, data on electricity generation by solar stations characterised by an optimal constant angle of inclination of the solar panel and equipped with a solar tracking system were used. By taking into account the varying ambient temperature, dust content, and solar transmission by the solar panel coating, the given algorithm allowed electricity generation by a solar panel to be forecasted with an average absolute error ranging from 0.22 to 9.8. To determine solar insolation for a specific day and the geographical coordinates of the intended construction site of a solar power plant, a mathematical model was developed using MathCad software. The experimental and computational studies carried out on selected clear days, accounting for varying weather conditions, demonstrated the adequacy of this method and its applicability for forecasting electricity generation with different inclination angles of a solar panel. It was established that a solar power plant with a solar tracking system generated 37% more electricity per year than that with fixed solar panels. The ASHRAE Clear-Sky method for calculating solar insolation allows the amount of electricity generated for a specific region to be estimated with minimal input data. Further research will focus on defining and improving methods for forecasting electricity generation by a solar power plant on overcast days.

The article focuses on the development of an effective design and algorithms for automatic control of singlephase DC electric locomotives according to the laws of constant traction force and power without switching electrical devices within power electric circuits. Methods of mathematical modelling for electromagnetic, electromechanical, and mechanical processes by MatLab, Simulink, and SimPowerSystems software were used to address this problem. The nonlinearities of the magnetisation curve were taken into account, along with the influence of eddy currents from the coils of the main and additional poles in traction motors. Structural and parametric synthesis of a power electrical circuit and control algorithms by controlled bridge IGBT converters were used in the simulation. The object of the research was an electrotechnical complex, including a 9840 kW three-stack electric locomotive 3ES5K “Ermak”. On the basis of the research results, it is recommended to use a power electrical circuit with two reversible converters for each of the three sections on the electric locomotive. These converters provide power to four 820 kW traction motors and a group power supply for controlled bridge IGBT converters shunting the field coils for axial traction control. The calculations confirmed the applicability of a scheme for individual control of traction electric motors and excitation currents, ensuring a smooth increase in the traction force of an electric locomotive. The developed algorithm of axial traction control ensures a smooth increase in this force and creates the optimal conditions for coupling the wheels of an electric locomotive with rails. These solutions can be used in the manufacture and modernisation of new and existing electric locomotives

This article is aimed at developing an algorithm for optimizing the operation modes of the electric power system of Mongolia, particularly the central power system that include not only conventional thermal power plants, but also renewable sources (wind and solar power plants). This power system accounts for a large share of electricity consumption and generation in Mongolia. The method of linear programming was chosen to minimize financial costs and active power losses during power generation at thermal power plants, while Newton’s method was used to minimize power losses. In addition, the article uses load schedules of each node of the studied power system for its modeling based on the ranking model. Load graphs are predicted using ensemble machine learning algorithms. After the optimization by the criterion of power loss minimization in the grid, power losses were found to be 3.05% of the total power consumption (with power losses in the basic variant of 3.12% and the average selling price of thermal power plants of 0.51 units). Thus, the reduction in losses amounted to 0.07 percentage points, or 2.24%. In terms of the cost minimization criterion, the average selling price of electricity was 0.49 units, i.e., decreased by 3.92%. Average losses of electric power in the grid decreased by 0.6%. According to empirical data, the suggested algorithms can be applied to the optimization of power distribution between thermal power plants by given criteria. The suggested algorithms are implemented using pandapower, a Python-based tool for power system analysis, thus creating a unified system of predictive analytics of power system operation modes

The article analyzes the development of methods for modeling and control of multi-energy microgrids through cyber-physical systems. We used the methods of literature review and meta-analysis based on publications from international databases Scopus and Web of Science, Russian database eLibrary, digital platform IEEEXplore et al. According to the analysis, Smart Grid implementation drives the development of cyber-physical systems. As summarized in this study, control interfaces, data transmission channels, and remote debugging ports are vulnerable parts of IoT devices that can possibly be attacked by intruders. A review of the recent publications in this field finds multi-agent technologies to be an effective approach not only for the operational control of multi-energy microgrid modes, but also for the construction of its reliable information network at the level of medium and low voltage systems. In the field of distributed energy systems, literature review of information technology indicates that the more capabilities are added to receive and process various kinds of information (transaction data, mode parameters, status of controllers, etc.) from external sources, the more vulnerable a multi-energy microgrid is to any cyber threats. Modern mathematical methods such as artificial intelligence, dynamic optimization, and multi-agent approaches should be used to effectively solve the problem of load distribution between different energy sources with cost minimization.

The aim is to develop an alternative technology of bauxite raw material processing based on low-temperature sintering of bauxite with caustic alkali, as well as to solve the issue of carbon footprint control at alumina refineries in the Urals. Laboratory tests were carried out by sintering artificial bemite and hematite with chemically pure caustic alkali at temperatures of 300, 500 and 700°C and their further leaching in weakly alkaline solutions. To study the phase, chemical, and particle size distribution of red muds after leaching, various physical and chemical methods of analysis were used, such as X-ray fluorescence, titration method, X-ray phase analysis, scanning electron microscopy, magnetometry with a vibrating sample. The Brunauer – Emmett – Teller method was used to determine the specific surface area and porosity. The study of the kinetics of the solid-phase reaction of the bemite interaction with caustic alkali has shown the kinetic interaction in the temperature range under study. Moreover, sintering of hematite at temperatures of 300 and 500°C and further leaching of the sinter with water resulted in mineralogical changes in the sludge with the production of a new mineral, maghemite, which possesses magnetic properties. When studying the magnetic properties of red mud of lowtemperature sintering of bauxite, we determined that the magnetization was as high as 19–20 electromagnetic units per g (at a sample density of 2.38 g/cm³) at a magnetic field of 10 kE. The specific surface area of these samples was 54.97 and 51.77 m²/g. The performed studies confirm that the proposed technology can be adapted for bauxite to produce highiron red slimes, thus contributing to the integrated processing of bauxite raw materials. In addition, ways to reduce carbon emissions at alumina refineries by eliminating the sintering operation with soda and limestone, which is accompanied by CO₂ emission during decomposition of these compounds, can be studied.

This study is aimed at developing a technology for obtaining petroleum pitch as a binder for anode mass used in the electrolytic production of aluminum from fuel oils of catalytic liquid-phase oxidative oil cracking. A review of published data on the existing methods for obtaining petroleum pitch and its properties is carried out in order to define research directions. A method for producing petroleum pitch by catalytic liquid-phase oxidative cracking of crude oil using heterogeneous metal complex catalysts is proposed. The process of petroleum pitch production is shown to undergo several stages, including homogenization of fuel oil and modifying additives; oxidative cracking of fuel oil during heating of homogenized fuel oil in a furnace; catalytic liquid-phase oxidative cracking of fuel oil with removal of distillates; rectification of light fractions; condensation of distillates; collection of light oil products; oxidation of bottom residues by air and steam; removal of oxidation distillates and petroleum pitch; and pitch pelletizing. According to the conducted comparison of the as-obtained petroleum pitch with the B-1 coal tar pitch produced by the Altai Koks JSC, the proposed material meets the technological requirements of the Krasnoyarsk Aluminum Plant of the RUSAL company. In terms of sulfur content, the proposed petroleum pitch is superior to coal tar pitch. The experiments conducted at an aluminum plant showed the petroleum pitch to contain no harmful polyaromatic hydrocarbons, in particular, carcinogenic benz(a)pyrene.  Therefore, replacement of coal tar pitch with petroleum pitch could provide technological and environmental advantages for primary aluminum producers, as well as for enterprises producing various carbon materials.

The study aims to investigate the most efficient method for significant minimization of the impact of organic carbon on gold recovery from double refractory raw materials. We tested three double refractory gold-sulfide concentrates from different deposits with the content of gold from 23.5 to 40.9 g/t and total carbon from 1.2 to 9.5 wt %. Thermal treatment was carried out in a tubular rotary furnace that provided permanent temperature setting and rotation speed in the reactor. The initial concentrate was grinded as pulp in a Fritsch planetary mono mill Pulverisette 6. Autoclave oxidation was performed in Premex and Büchi titanium autoclaves. The technology of autoclave oxidation with the addition of a secondary oxidizer was found to be the most efficient, since it can increase gold recovery up to 97%. Another technology – hightemperature autoclave oxidation – also proved high performance; however, a significant increase in the residence time of the material in the autoclave (up to 120 min) at elevated temperatures is required to achieve this performance. According to the results, thermal treatment in general can provide a small increase in gold recovery (up to 4%). Due to this, it can be used as an additional processing with other methods analyzed in this article rather than as a self-sufficient technological solution. The studies revealed that the preliminary thermal treatment of concentrates entering autoclave oxidation shows a positive effect; high-temperature autoclave oxidation of concentrates with different carbon content provides high gold recovery for high-carbon concentrates; the use of a secondary oxidizer (in the form of nitric acid) also benefits the gold recovery. The high efficiency of the technology for concentrates with different carbon content allows us to recommend it for further research.

The article evaluates the main parameters of simultaneous heap leaching of gold and uranium from oxidised gold-uranium ore using sulphuric acid thiocyanate solutions. Pilot tests for the simultaneous heap leaching of gold and uranium were carried out using oxidised crushed gold-uranium ore with a size of -40+0 mm. The gold and uranium content in the ore was 0.80 and 266 g/t, respectively. Experiments were carried out using a percolation column with a diameter of 300 mm and a height of 2000 mm The ore mass in the column was 180 kg. The temperature during the tests was in the range of 17–25°C. Leaching was carried out under the following conditions: H₂SO₄ concentration – 5 g/dm³, SCN^– concentration – 0.5 g/dm³, Eh – 490–510 mV, Fe³⁺ ion concentration – 1.0–1.5 g/dm³. Acid-soluble minerals contained in the ore comprised the source of iron ions. Hydrogen peroxide was used to oxidise Fe²⁺ ions. Pilot tests were carried out in a closed cycle with separate sorption of gold and uranium. Based on the research results, gold recovery reached 90%, while uranium recovery was 55%. Following gold and uranium leaching, the loaded activated carbons and ion exchange resins were obtained. It was established that the gold content on activated carbons was 0.5–0.6 mg/g, while the uranium content on ion exchange resins amounted to 30–35 mg/g. The reagent consumption was as follows: H₂SO₄ – 10.5 kg/t, KSCN – 0.94 kg/t, H₂O₂ – 0.65 kg/t. It is shown that the technology for simultaneous heap leaching of gold and uranium with sulphuric acid thiocyanate solutions offers efficient processing of the ore. The recovery rates of gold and uranium are comparable to those obtained during pilot tests for heap leaching of the ore using conventional technology, involving the individual twostage leaching of these metals using sulphuric acid and cyanide solutions.