Journal of Electrical and power engineering最新文献

{"title":"Investigation of the possibility of increasing heat exchange efficiency in modified trapezium screw pipes profile of fuel oil heater PM-40-15.","authors":"V. M.","doi":"10.31474/2074-2630-2021-2-62-68","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-62-68","url":null,"abstract":"Recently, a special direction in solving the problem of intensification of convection heat exchange, which is based on the idea of influencing the micro- and macrostructure of the flow of heat carriers by various swirls in the channels of their movement, has been widely developed in industrial heat engineering. Despite the huge number of publications on this topic, the issue of improving the effectiveness of heat exchangers remains far from its final solution. The research is aimed at studying the possibilities and limits of increasing the efficiency of heat transfer in the modified trapezoidal helical profile of the inner surface of the pipes of the fuel oil heater PM-40-15. To achieve this goal, the method of computer simulation using SolidWorks software was used. In this program, a geometric model of a fuel oil heater was created with both smooth standard pipes and modified pipes with trapezoidal profiles with a height of h = 2, 3 and 4 mm and relative steps of the screw profile S/D = 0.6, 0.8, 1.0, 1.2 and 1.5. The temperature of fuel oil M100 at the inlet of the fuel oil heater was taken to be 60°С, and the temperature of the walls of the pipes washed with superheated steam at a pressure of 1.0 MPa, 200°С. These parameters corresponded to the nominal mode of operation of the fuel oil heater PM-40-15. As a result of the research, it was found that the best efficiency indicators are achieved on pipes with a profile height h = 2 mm and a relative step S/D = 0.8.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"292 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131708642","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 mode of operation of the electrical network with the development of measures to compensate for reactive power.","authors":"N. E.","doi":"10.31474/2074-2630-2021-2-41-47","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-41-47","url":null,"abstract":"The article identifies the main measures for energy saving, among which the need to develop and implement methods and devices for reactive power compensation. It was noted that the sign of energy systems of industrial enterprises is irrational management of reactive power flows, the presence of a wide range of harmonic oscillations in the network, violation of temperature modes of individual components of electrical equipment, which leads to reduced equipment life, increased costs. The main reasons for the low value of the power factor in energyintensive industries are the presence and use in technological processes of a large number of induction motors, the power factor of which according to passport data is 0.8 under nominal operating conditions. It is noted that in practice there are often cases when the engines run in modes other than nominal - they are underloaded or overloaded, there are frequent starts of engines under load and their long operation at idle. These modes of operation of induction motors are characterized by an increased level of reactive power. The low value of the power factor leads to increased losses in the conductors, which are directly proportional to the \"square\" of reactive power, which requires the use of conductors of increased cross-sectional area. The paper proposed design solutions for energy saving in existing technological schemes of power supply: by analyzing the existing situation and calculating the real value of the power factor were calculated and selected reactive power compensation units.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124337712","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":"Justification of the optimal structure of a hybrid autonomous microgeneration system.","authors":"S. N.","doi":"10.31474/2074-2630-2021-2-18-22","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-18-22","url":null,"abstract":". The issues of optimization of the composition of energy sources and storage units in hybrid autonomous microgeneration systems are considered. The development of renewable energy, namely its decentralization and autonomy, is today the main issue in the energy sector. At the same time, it is a solution to the problems of an increasing level of electricity consumption and an increase in carbon dioxide emissions into the atmosphere during electricity production. The introduction of small-scale power generation, namely autonomous microgeneration systems, is an extraordinary task that needs an immediate substantiated solution. The use of one type of power supply in stand-alone systems is unreliable and inefficient. In the process of evolution of autonomous systems, so-called hybrid systems have appeared, using several power sources with different principles of generating electricity. The article presents a new approach to the classification of hybrid autonomous systems based on the degree of hybridization of its components. Justification of the optimal composition of a hybrid autonomous microgeneration system, namely the optimal composition of sources and storage of electricity, is closely related to the determination and optimization of its operating modes. An integrated approach to optimizing the composition and operating modes of an autonomous microgeneration system with renewable energy sources and active consumers of electricity is considered. The algorithm developed in the article for a comprehensive substantiation of the composition and operating modes of a hybrid autonomous system is based on the calculation and comparative analysis of the energy characteristics of the hybrid components of an autonomous system, taking into account the needs of power supply of a particular consumer and with reference to the climatic conditions of its location. On the basis of the analysis, the structure of the optimal hybrid autonomous microgeneration system is proposed, which has high energy performance due to the rational choice of the installed capacities of generating and accumulating sources. The system has a high level of reliability and environmental friendliness, which is an important aspect of the development of decentralized energy. For the proposed structure, an algorithm for controlling the operating modes of a system with renewable hybrid energy sources and a hybrid energy storage system has been developed. A mathematical model of the proposed hybrid autonomous microgeneration system is presented.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116823729","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":"Improving the reliability of energy supply to consumers in distributed generation networks.","authors":"O. D., K. O.","doi":"10.31474/2074-2630-2021-2-69-75","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-69-75","url":null,"abstract":". During the work [1] it was shown how, thanks to the developed algorithm, it is possible to disconnect consumers in the distributed generation network, with insufficient power at the output of the photovoltaic plant and reconnect them when the power value is sufficient. However, the paper did not pay much attention to switching consumers to the centralized grid and the issue of charging and discharging the battery station. Therefore, when writing this paper, the aim was to study the above issues on the installation of \"Photovoltaic Station\", as well as on the relevant mathematical model. As a result of the study, the process of electricity transmission from the generation facility - the solar station, to the consumption facility - the electric drive was improved. To successfully solve the problem, the following goals were set and solved: to analyze possible ways to switch the consumer to backup power sources; to develop an algorithm for controlling the charge / discharge of batteries; to improve the mathematical model developed earlier in [1]; thanks to the STM32F46NG DISCOVERY board to perform the practical implementation of the accepted theoretical provisions regarding switching algorithms. The purpose of this research is to develop a control system for consumer power supply in the power system. The control of the photovoltaic power plant due to the use of the STM32 board is considered in [2] and [3], the result of these experiments was the practical implementation of automated data collection and subsequent control in the photovoltaic power plant.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125280047","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":"Design and development of the photovoltaic station of Donetsk National Technical University","authors":"O. D., K. O.","doi":"10.31474/2074-2630-2021-2-53-61","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-53-61","url":null,"abstract":"This article considers the principle of creation and operation of a stand called \"Photovoltaic Station\", which is located on the basis of \"Donetsk National Technical University\" in Pokrovsk. The mathematical model of this stand is also given. The purpose of this study is to analyze the operation of a real solar power plant and develop a mathematical model to predict the results that will be obtained when working with a physical model. The article uses both empirical research methods: description, measurements, experiment and comparison, and theoretical - formalization. To achieve the main task in the work the following stages are performed: Development of constructive decisions concerning change of an angle of inclination of solar panels; Improving models of graphical programming of photovoltaic systems using artificial intelligence; Forecasting the results of the solar panel using neural networks; Identifying the value of the efficiency of photovoltaic installations that use optimized parameters. The results of such a system will allow additions to the topology of the artificial neural network, which will help determine the correct direction of the neural network. The correct direction of the artificial neural network means the case when the difference between the objective function and the output of the neural network tends to converge. The paper presents the method of selection and parameters of the main elements of the installation, block diagrams, electrical diagrams and models of the developed structures. A mathematical model of the stand was developed and modeled in the Matlab software package. The obtained results allowed us to conclude that the mathematical model has the same properties as a real photovoltaic station and can be used in the future to model accidents and pre-accidents in the electrical network. It was also concluded that it is important to pay attention to the architecture and method of neural network training in this power system.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127348183","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 mode of electrical network operation at single-phase accessories of voltage 6-35 kV","authors":"S. S., K. O.","doi":"10.31474/2074-2630-2021-2-35-40","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-35-40","url":null,"abstract":"In three-phase electrical networks during the operation of power supply systems, damage to electrical equipment and difficult modes of operation are possible. Damage associated with insulation failure, rupture of wires and cables of power lines, personnel errors when switching, lead to a short circuit between the phases or on the ground. At a short circuit in a closed circuit there is a big current, voltage drop on elements of the equipment increases that leads to the general decrease in voltage in all points of a network and disturbance of work of consumers. Complex modes of operation of electrical networks occur, as a rule, as a result of accidents or after emergency shutdowns of equipment, with subsequent overloads and voltage deviations from the nominal values. And although these modes have been considered acceptable for some time, they create the preconditions for various types of damage and disorders in the operation of power grids. To ensure normal operation of electrical networks and prevent the development of accidents, it is necessary to respond quickly to changes in the mode of operation of the electrical network, immediately separate damaged equipment from serviceable and, if necessary, turn on a backup power supply. These functions are performed by relay protection and automation devices. Principles of operation of relay protection devices. 1. Current protection. Short circuits are accompanied by a sharp increase in current that exceeds the value predetermined by the calculation, which will perform simple relay protection devices that can control the value of currents. Separate the maximum current protection, which acts to disconnect the damaged network element with a time delay and current cut-offs, which operate without a time delay. The difference between them is in the choice of how to ensure selectivity. The currents controlled by the relay protection device can be measured in phases (through current transformers), or individual components of phase currents can be measured (currents of direct, reverse and zero sequences. This method is based on the method of symmetrical components). Current types of protection are divided with control of power direction (directional) and without control (non-directional). Current protection works on the principle of operation not only in case of damage to one of the network elements, but also to adjacent ones. Therefore, current protection is referred to as protection with relative selectivity. 2. Differential protection. The basis of the principle of differential protection is the comparison of homogeneous, instantaneous values at the ends of the protected element of the network (transformer, busbar section, generator, overhead line). Usually compare currents in magnitude and phase. Differential protection by its principle works only in case of damage to the protected element of the network, so it is performed without time delay and differential protection is called protection with absolute sel","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130382728","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":"Control and diagnosis features of the technical condition of electrical equipment","authors":"P. I., K. V., K. D.","doi":"10.31474/2074-2630-2021-2-76-79","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-76-79","url":null,"abstract":"The article considers the technical possibilities of early detection and prevention of electrical equipment malfunctions. Monitoring the technical condition of electrical equipment is crucial, the quality of such equipment must be extremely high to ensure adequate reliability during operation, and maintenance and adjustment to have high quality indicators. Since the ability to monitor the parameters of electrical systems during their operation is limited and often reduced to monitoring the performance of existing meters, special attention should be paid to quality and comprehensive diagnostics when maintaining such systems. One of the widely used methods of increasing the life of electrical equipment at the stage of its development is the simplification of circuit solutions, respectively, reducing the number of elements in the product. It is known that the fewer individual elements in the product, the less likely it is to fail. Even if complex electrical equipment consists of many elements of high reliability, in general it has low reliability due to the presence of a large number of elements in its design, connected in series. The expediency of increasing the life of electrical equipment at the stage of its development by simplifying circuit solutions, respectively, reducing the number of elements in the product is also limited. The consequence of simplifying the circuit solutions of electrical equipment is quite natural to reduce its functionality. During the operation of electrical equipment should be a constant comprehensive monitoring of its condition and important parameters. Various technical and economic measures are used in the industry to ensure the necessary reliability and trouble-free operation of electrical equipment. We consider it necessary to develop computer models of probability of failure, taking into account the operating conditions and the actual load for each individual electrical device or network.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"131 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130802061","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":"МЕТОДИКА ОЦЕНКИ РЕСУРСА ЭНЕРГЕТИЧЕСКОГО ОБОРУДОВАНИЯ МЕТАЛЛУРГИЧЕСКИХ ЦЕХОВ","authors":"V. A., Z. S.","doi":"10.31474/2074-2630-2021-2-6-11","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-6-11","url":null,"abstract":"Prognostic is central to manufacturing and infrastructure management. The development of new methods for determining the residual resource of equipment is an important task aimed at increasing the efficiency of using industrial electrical complexes. Solving the problem of reliably determining the state of power equipment in the mining and metallurgical complex makes it possible to move from an outdated system of scheduled preventive maintenance to maintenance based on the current state of the unit. Complex technical systems are characterized by complex nonlinear interactions between their constituent elements, complex scenarios of cause-and-effect relationships between hazardous, probabilistic events and processes occurring during their operation. Therefore, methods and tools are being developed to assess and manage wear mechanisms in high-risk industries. The sources of information in the systems of technical diagnostics and control of technological processes are measuring transducers (sensors) of physical quantities. Using information from sensors and real-time operational diagnostics, the operator can predict the occurrence of malfunctions, equipment failures and process disturbances, which reduces downtime of process equipment and the occurrence of emergency situations. The article presents the results related to the development of a methodology for assessing the residual life of industrial equipment. The methodology uses probabilistic mathematical methods to predict the remaining service life and information collected during audits and equipment monitoring. Along with the classical methods, methods are presented based on the use of the entire potential of the modern element base of microprocessor technology and technologies for the use of artificial neural networks, machine learning, \"big data\".","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122276440","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 the concept of increasing the energy efficiency of electric arc furnace by flue gases heat utilization for scrap preheating","authors":"T. S. M., DZERZHYNSʹKYY V. O., TSARʹOV A. V., G. O. A.","doi":"10.31474/2074-2630-2021-2-23-34","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-23-34","url":null,"abstract":"An important factor in improving the energy efficiency of the electric arc steelmaking furnace (EAF) is utilization of the flue gas energy to preheat the initial charge. Implementation of the process in existing EAF requires the measures to synchronize with the carbon monoxide post combustion and to prevent of the toxic PCDD/F formation when conventional scrap heating, which is significantly complicated in a traditional scheme of CO afterburning with a single-stage air inflow through a temperature and concentration factors. The technological basics of medium-temperature scrap preheating by EAF flue gas have been developed and substantiated. Numerical study of carbon monoxide burning thermodynamics and kinetics shown that implementation of two-stage inflow of air into postcombustion chamber for stoichiometric combustion of CO and cooling the heat carrier provides a comprehensive solution of mentioned problems. The ratio of primary and secondary flows 1 to 3.5 provides allowable concentration of carbon monoxide in the ducts; obtaining gas mixture with a temperature of up to 500 °C, which prevents PCDD/F formation; acceptable temperature operating conditions of bag fabric filters of the gas cleaning system within 100 °C regardless of scrap preheating. Numerical simulation of the heat exchange process between the charge layer and the gaseous heat carrier reveal that shredder scrap of standard bulk density 0.9 t/m3 and mass of half EAF capacity can be preheated up to temperature of 450 °C in 18-20 minutes. Given value corresponds to the duration of technological period in the EAF heat cycle, characterizing by comparatively stable emission and maximal temperature of the flue gas flow. Reduction of the scrap fragments bulk density and the average size, as well as increasing the ratio of the heating chamber height to its diameter in the range from 0.7 to 2.0, promotes the heating rate magnification. The technology provides specific energy savings within 20-30 kW.h per ton of steel and can be implemented in existing electric steelmaking shop of the mini-mill without additional CO2 emissions. The payback period for a 50-ton EAF with annual productivity of 400-450 thousand tons of steel is 14-18 months.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127252340","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":"Receipt of electricity from heating battery.","authors":"L. E., Shtepa A.A., Sikirin D.R.","doi":"10.31474/2074-2630-2021-2-48-52","DOIUrl":"https://doi.org/10.31474/2074-2630-2021-2-48-52","url":null,"abstract":"As a result of the analysis of the research results, the volt-ampere characteristic of the Peltier element used in the mode of temperature difference generation and the dependence of the temperature difference on the \"hot\" and \"cold\" surfaces on the consumed electric power were obtained. It is determined that the efficiency of the element decreases with increasing power consumption, when when a significant temperature difference is reached, the element between the heated and cooled surfaces can not sufficiently perform the functions of thermal insulation. It has been experimentally determined that it is expedient to use Peltier elements in the temperature range when the difference is from 13 to 25 ° C, and this is possible in the presence of an effective mechanism of heat dissipation from the hot side. Thus, when developing devices with thermoelectric cooling, it is advisable to choose the optimal mode of operation with a voltage below the nominal. The work of the element was experimentally tested on the basis of EMF determination for one element of TPP 1– 12706. The experimental dependences of the plate and radiator temperature on the generated EMF for the Peltier element TPP 1 - 12706 were obtained. and quality of TE devices. The scientific novelty of the work is to confirm the possibility of creating a heat generator using as a source of energy available in everyday life temperature difference, in particular, the dependence of the generated EMF on the temperature difference between \"hot\" and \"cold\" side Peltier TPP 1 - 12706 The practical significance of the work lies in the possibility of using the device in domestic conditions when using a battery with heating to obtain electricity that can be used to connect a flashlight, humidifier device, charge the phone.","PeriodicalId":174144,"journal":{"name":"Journal of Electrical and power engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129109590","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}