Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ "Elektrotehnìka i energetika"最新文献

{"title":"Solving optimization problems in energy with genetic algorithm.","authors":"KARDASH D., KOLLAROV O.","doi":"10.31474/2074-2630-2023-1-37-41","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-37-41","url":null,"abstract":"The article discusses the application of genetic algorithms in the field of energy optimization. Linear programming is commonly used for optimization problems in energy systems. Linear programming is a mathematical optimization method that seeks the optimal solution under constraints, where all constraints and the objective function are linear functions. In the realm of artificial intelligence,genetic algorithms are employed for optimization tasks. genetic algorithms mimic natural evolution processes, including selection, crossover, mutation, and adaptation, to solve optimization and search problems. The article outlines the process of a genetic algorithm, starting with the formation of an initial population and proceeding through selection, crossover, mutation, and evaluation. This cycle repeats until an optimal solution is achieved. Advantages of genetic algorithms include their ability to handle complex solution spaces, find global optima, adapt to changing conditions, optimize multi-objective functions, and work with non-linear and non-differentiable objective functions. However, they may require significant computational resources and parameter tuning. The article then presents a case study of applying a genetic algorithm to optimize the allocation of a power load in an energy system. The mathematical model is developed, and the simplex method is initially used for solution. Subsequently, a Python program for genetic algorithm implementation is provided. The algorithm's efficiency and convergence are demonstrated through a graphical representation of the optimization process. In conclusion, the article highlights the effectiveness of genetic algorithms in energy optimization, showcasing their rapid convergence and ability to find near-optimal solutions in complex scenarios.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficiency of application of maximum current protection in underground networks.","authors":"KALYNYCHENKO V.","doi":"10.31474/2074-2630-2023-1-53-56","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-53-56","url":null,"abstract":"The article considers the use of maximum current protection in underground mine electrical networks, which disables short-circuit currents with an absolute value greater than the starting currents of powerful electric motors. It was determined that these protections have a number of disadvantages. The article reveals that the protection with the current-time characteristic is more perfect than the maximum current protection, but in the case of arcing short circuits, the values of which can be less than the starting ones in absolute value, the protection activation time significantly exceeds the permissible value. Protection with filters of symmetrical components of currents and voltages reduces the sensitivity to two-phase short circuits with a connected load, protection at the level of the third harmonic in the event of a short circuit has a limited range of action and requires duplication. It was investigated that with the use of valve converters and thyristor schemes for controlling the drives of lifting installations and conveyor transport in underground networks, the level of higher harmonic currents increased. In the practice of work of domestic and foreign enterprises, it has been proven that capacitor banks, which are installed to compensate for reactive power, have protection against overcurrents and shortcircuit currents, but with non-sinusoidal voltage, in a number of cases, they quickly fail because they are overloaded with higher harmonics. The article shows that with the increase in the power of the engines of the underground district networks and the manifestation of the asymmetry of the air gap, the higher harmonics given exceed the permissible values. Therefore, the article presents the most promising directions for the construction of systems for the protection of mine distribution underground networks and electrical installations","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"363 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of autonomous energy supply of a mobile surface degassing plant.","authors":"SERHIIENKO L. V.","doi":"10.31474/2074-2630-2023-1-47-52","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-47-52","url":null,"abstract":"Currently, in connection with the difficult situation with energy supply, issues related to the application of new measures to conserve energy resources as well as the introduction of new promising technologies using alternative energy sources, such as mined methane, have gained great importance. The problem of methane from coal deposits is of particular importance. This problem primarily concerns the safety of miners' work, methane production as an alternative source of energy resources, and solving environmental problems related to methane emissions into the atmosphere of coal mining enterprises. The problem of reducing the efficiency of degassing is caused by the long length of the degassing pond and the depth of cleaning operations. The use of a mobile surface degassing unit makes it possible to effectively carry out degassing and achieve significant volumes of extracted gas with a methane content of up to 80%, but high costs of electricity complicate its operation. Therefore, the paper proposes an autonomous power supply for a mobile surface degassing plant. For the autonomous power supply of a mobile surface degassing plant, it is advisable to use an electric generator since an uninterrupted supply of electricity is important. Gas power plants are widely used in industrial enterprises. In accordance with the power consumption of the electrical equipment of the mobile surface degassing plant, the work justified and selected a gas power plant and electric power equipment for the autonomous power supply of the mobile surface degassing plant. The gas-piston power plant is designed for the production of electrical energy and can be both the main and backup source. As a fuel, mainline natural gas with an average supply pressure or methane mine gas is used. The basic configuration of the power plant is a liquid-cooled gas-piston engine based on a diesel unit. A technological scheme for connecting the gas power plant to a mobile vacuum pumping unit and its power supply scheme has been developed, which will increase the safety of cleaning works, solve the issue of methane utilization, significantly reduce electricity costs, and improve the environmental situation in the industrial region.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of the design of water-cooled panels of arc steelmaking furnaces of foundry class.","authors":"VLASENKO M., NIEMTSEV E.","doi":"10.31474/2074-2630-2023-1-19-25","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-19-25","url":null,"abstract":"The article outlines the importance of the foundry industry and the role of arc steelmaking furnaces (ASFs) in it. It was noted that water-cooled panels in EAFs are key elements that ensure the structural integrity and safety of furnaces by removing excess heat during steelmaking. An analysis of literature sources has revealed that there are certain issues that characterize the imperfections of certain structural parts of modern water-cooled panels, such as insufficient cooling efficiency, corrosion, and leaks, which lead to a decrease in the performance of the BF and an increase in energy consumption. These factors have been analyzed and some optimization ways have been identified to improve overall efficiency and durability. The article emphasizes that modern technologies can reduce the consumption of energy and refractory materials by reducing the capacity of the steelmaking bath and optimizing the heat balance. Particular emphasis is placed on the potential for modernizing water-cooled panels to improve the efficiency of the steelmaking process. The paper reveals the mechanism of operation of water-cooled chipboard panels as a spatial system of steel tubes connected by means of transition elements and placed with different densities and a layer of thermal insulation material in the intertube space. This determined the need to improve the design of the panels by optimizing their spatial structure to ensure a more efficient heat transfer process. Improving the energy efficiency of chipboard means reducing heat energy losses, which, among other things, ensures more stable operation during melting, reduces component wear and extends the service life of water-cooled panels. The design of the water-cooled panels has been improved by varying the distance between the axes of the water-cooled tubes depending on their diameter and spatial location. This design makes it possible to optimize the layer of heat-insulating material and minimize unproductive heat loss. Failure to comply with the calculated value of the pipe spacing can lead to increased heat loss. The calculations and graphical dependencies demonstrate the efficiency of heat flow distribution and minimization of heat losses. The new design reduces heat loss by 45% and improves the performance of water-cooled panels.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STUDY OF INFLUENCE OF IMPULSE PROCESSES IN TRANSFORMER WINDINGS.","authors":"LYUBIMENKO О., SHTEPA A.","doi":"10.31474/2074-2630-2023-1-42-46","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-42-46","url":null,"abstract":"The article examines the existence of uneven voltage distribution under the action of transient voltage, which is the main cause of insulation breakdown of power transformers. In fact, the winding of the power transformer has no tap and cannot be directly used to measure the impulse voltage. The study of pulse voltage distribution measurement is important and practical in engineering. The voltage distribution for the isolated neutral, when the current does not flow through the winding ipr = 0, occurs according to the exponential dependence, and the amount of overvoltage is equal to the initial voltage on the winding of the transformer, which decreases. When the induced voltage is varied along the winding of a transformer with an isolated neutral in steady state, the entire winding takes the same potential with respect to ground and the steady voltage is a straight line. It follows that in the case of an insulated neutral, the end of the winding must have the same insulation as the beginning. The change in maximum voltage is presented when U0 changes in the range from 550 kV to 850 kV. In the work, the change of U0 from values (550-850 kV) to 0 V was studied, with the length of the coil wire x=l= 100 m. Thus, in both cases, it is not difficult to determine the sum of the amplitudes of individual harmonics at any point of the winding. During the development of self-oscillations, the voltage exceeds the set value, and tends to decrease the frequency of self-oscillations. On the basis of the conducted research, transient overvoltage distributions in the transformer windings were calculated. These results will be useful for designers to evaluate the resistance of transformer insulation to transient voltages and further optimize the graded longitudinal insulation. Transient overvoltage distributions in transformer windings are modeled. It was concluded that the impulse voltage distributions in the transformer windings are mainly related to the high-frequency components of the winding voltage.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of electromagnetic transient processes in an industrial low-voltage distribution network with induction load.","authors":"DAVYDENKO L.V., DAVYDENKO V.A.","doi":"10.31474/2074-2630-2023-1-5-11","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-5-11","url":null,"abstract":"The article is devoted to the issue of short-circuit analysis in the low-voltage network of the power supply system of an industrial enterprise. The analysis methodology is based on the recommendations of the IEC 60909 standard and the ANSI/IEEE C37 series standard, which regulate the calculation of short-circuit current for the selection and verification of switchgear and protective devices according to the level of short-circuit current. The Electrical Transient Analyzer Program (ETAP) software was used as an analysis tool. Short-circuit analysis is performed in two stages: the first stages involves modelling the low-voltage distribution network of the industrial facility; the second stages involves the simulation of faults in the network. The modelling the low-voltage distribution network takes into account the features of the network configuration with inductions motors used in the technological process. The Short Circuit module of the ETAP software was used to calculate the short-circuit current on the bus of the distribution network. The performed analysis takes into account the induction motors contribution to the level of short-circuit current. The result of the analysis is the determination of symmetrical and asymmetrical short-circuit current values and the detection of inconsistency of the characteristics of the installed equipment with short-circuit currents. Analysis of short-circuit current using ETAP software provides the possibility of selecting switchgear and protective devices according to the level of short-circuit current and verify the correctness of the decisions made regarding the selection of low-voltage switchgear of the distribution network, which contributes to the design of a reliable power supply system for the facility.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the efficiency of the heat exchange process in the MO-2 cooler of turbine oil depending on the arrangement scheme of tubes in tube grids.","authors":"VLASENKO M., NIEMTSEV E.","doi":"10.31474/2074-2630-2023-1-12-18","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-12-18","url":null,"abstract":"Effective cooling of the turbine oil is important for the reliability and optimal operation of the turbogenerator. The oil is used for lubrication and cooling of the support and radial bearings of the turbine, bearings of the generator and reducer, gears and splined rollers. It is also used as a hydraulic fluid in the hydraulic turbine start-up system. For reliable and safe operation of the system, it is necessary to maintain the correct temperature of the lubricant. Research is aimed at studying the influence of the layout of the heat exchange tubes in the tube grids on the cooling efficiency of the TP-22 turbine oil. With the help of the SolidWorks software complex, a geometric model of the MO-2 turbine oil cooler was created with three schemes for the placement of heat exchange tubes in tube grids: corridor, radial and checkerboard. Adhering to the parameters of the technical characteristics of this cooler, the nominal parameters of temperatures and consumption of coolants (cooling water and turbine lubricant TP-22) were chosen. The result of the calculations were the temperature fields of the coolants and the trajectories of the movement of lubricant particles in the intertube space of the cooler. When creating a geometric model and further research, the main technical characteristics of the shell-and-tube horizontal cooler MO2 were adopted, namely: the temperature of the turbine oil at the inlet is 45°С, the nominal flow rate of the oil is 3.1 m3/h, the temperature of the water at the inlet is 20°С, the nominal flow rate water - 15 m3/h. The conducted computer modeling made it possible to investigate the influence of the layout of the heat exchange tubes in the tube grids on the cooling efficiency of the turbine lubricant in the MO-2 shell-and-tube cooler. It was shown that the most effective, among the studied schemes, is the checkerboard arrangement of heat exchange tubes in tube grids. This scheme makes it possible to reduce the consumption of cooling water, relative to the nominal one, which will allow the use of water pumps of lower power.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of load amplitudes on the drive of a mine horizontal belt conveyor by transportation route adjusting","authors":"BELYTSKYI Р., LIUBIMENKO O., SHTEPA O.","doi":"10.31474/2074-2630-2023-1-26-30","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-26-30","url":null,"abstract":"The article examines the nature of the dependence of the amplitudes that arise on the drive of a mine belt conveyor from changes in the belt load, from the angle of transportation, as well as technological parameters of transportation and design parameters of the drive and the mechanical part of the conveyor. These amplitudes have a significantly affect to the resource of the mechanical and electrical parts of the conveyor, in particular: the conveyor belt, reducer, electric motor, etc. A mathematical model of the load amplitude formation on the elements of the mechanical and electrical parts of the belt conveyor drive due to the fluctuation of the belt load has been developed. The nonlinear nature of the amplitudes’dependence that arise on the mine belt conveyor drive from the variable load of the belt and from the angle of transportation has been established. Graphically and analytically, the characteristic angle of installation of the belt conveyor is determined, at which the moment of resistance does not depend on the belt load and will remain constant under the existing fluctuations in the amount of the mass of the cargo on the conveyor belt. Mining technical conditions that correspond to the transportation of bulk cargo by a belt conveyor at the installation angle described above are recommended as rational from the point of view of minimizing the amplitudes of loads on the conveyor drive, which is expected to increase the conveyor's resource and its reliability in general. The functioning of conveyors with minimum load amplitudes by the mechanical and electrical part of their drive corresponds to the operating conditions of horizontal and slightly inclined conveyors with the value of the angle transportation of the cargo down. The modulus of this angle is equal to the arctangent of the tape motion resistance coefficient.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the influence of the temperature of the external environment on the operation of the photoelectric stations.","authors":"OSTRENKO D., KOLLAROV O.","doi":"10.31474/2074-2630-2023-1-31-36","DOIUrl":"https://doi.org/10.31474/2074-2630-2023-1-31-36","url":null,"abstract":"This work is devoted to the study of the mechanism of increasing the efficiency of solar photovoltaic generation by integrating the compressed air system. The main aspects of this mechanism, its advantages and influence on the improvement of the process of converting solar energy into electrical energy are considered. The relevance of this topic is due to the constant growth of electricity consumption and the need to create efficient and sustainable solar power plants. Solar photovoltaic generation is already a promising source of renewable energy today, but it has certain limitations, in particular, related to the increase in temperature of solar panels and uneven distribution of solar radiation. This paper examines the integration of a compressed air system with solar panels to increase the efficiency of solar PV generation. The use of compressed air allows you to lower the operating temperature of the panels, which leads to an increase in the efficiency of solar energy conversion. In addition, it helps to unify the lighting of the panels and improves the performance of all photovoltaic modules. An important aspect of the work is the analysis of the influence of the integrated compressed air system on the energy characteristics of solar panels. The study includes modeling and experimental determination of changes in efficiency, energy output, and stability of solar panels when using a compressed air system. The obtained results allow us to draw conclusions about the efficiency and practical implementation of an integrated system of compressed air for solar photovoltaic generation. The identified advantages of this approach make it possible to recommend it for use in modern solar power plants in order to increase efficiency and ensure stable operation.","PeriodicalId":473065,"journal":{"name":"Naukovì pracì Donecʹkogo nacìonalʹnogo tehnìčnogo unìversitetu. Serìâ \"Elektrotehnìka i energetika\"","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}