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  Problemele energeticii regionale

E-Journal N1-1(40) 2019

"PROBLEMS of the REGIONAL ENERGETICS (special issue)"


1 Mathematical Simulation of Modes and Characteristics of Asynchronous Motors under Asymmetrical Power Supply
Authors: MalyarV.S., Hamola O.Ye., Maday V.S, Vasylchyshyn I.I. Lviv Polytechnic National University Lviv, Ukraine
  Abstract: The purpose of this article is to develop a method and algorithm for the calculation of the steady-state mode and static characteristics of the squirrel-cage asynchronous motors that are supplied by a three-phase network with an asymmetrical voltage system. The aim is achieved by developing a method where the mathematical model of the motor takes into account the saturation of the magnetic core and the current displacement in the short-circuited rotor bars. Magnetization characteristics of the main magnetic flux and the leakage fluxes paths are used to account for the saturation. To account for the current displacement in the rotor winding the bars are divided into several layers throughout the height, resulting in a number of windings on the rotor with mutual inductive couplings. In the mathematical model, the processes in the asynchronous motor are described by a system of the nonlinear differential equations of electromagnetic equilibrium, composed in the fixed three-phase coordinate axes. The solution of this system in the steady-state mode is the periodic dependence of the currents, which are determined by solving the boundary problem. For this purpose, their algebraization is carried out by approximation of the periodic dependences at the nodes’ grid of the period of repeatability of the process by the third order splines. The solution of the problem is to determine the nodal values of coordinates on the period from the obtained nonlinear system of algebraic equations. For this purpose, the continuation method and iterative refinement by the Newton method were used. Calculation of the static characteristics was performed by the differential method.
  Keywords: asynchronous motor, three-phase coordinate system, magnetic saturation, current displacement, boundary problem, spline approximation, parameter continuation method.
DOI: 10.5281/zenodo.3239128
2 Active Shielding of Power Frequency Magnetic Field in Buildings in the Vicinity of the Electric Airlines
Authors: Kuznetsov B.I., Nikitina T.B., Bovdui I.V. State Institution «Institute of Technical Problems of Magnetism of the National Academy of Sciences of Ukraine» Kharkiv, Ukraine
  Abstract: The purpose of the work is the development of the method for the synthesis of a robust feed-forward active shielding system of the magnetic field, generated by high voltage power lines for reducing the initial magnetic field induction to the sanitary standards level and decreasing the system sensitivity to the plant parameters’ variations. This work is devoted to the solution of a multicriterion stochastic game, in which the vector payoff is calculated based on the Maxwell equations solutions in the quasi-stationary approximation. The multicriterion game solution depends on the multiswarm particles optimization algorithms. The initial parameters for the synthesis of the active shielding system are the location of the high voltage power lines with respect to the protected from transmission line space, geometry and number of buses, operating currents, as well as the size of the protected space and magnetic field induction normative value. The aim is achieved by determination of the number, configuration, spatial arrangement, and currents in compensation coils, setting algorithm of the robust feed-forward active shielding system of the magnetic field, as well as the resulting value of the induction magnetic field at the points of the protected space. New scientific results of the theoretical and field experimental researches of the effectiveness of a single circuit active shielding system with a single compensation coil are carried out. The possibility of reduction of the initial magnetic field induction level is obtained. It is shown that the experimental and calculated magnetic field induction values differ up to 20 %.
  Keywords: high voltage power lines, magnetic field, robust active screening system, theoretical and field experimental research.
DOI: 10.5281/zenodo.3239128
3 Improvement of Energy Indicators of Asynchronous Motor under the Conditions of Asymmetric Voltage Supply
Authors: Boyko A.A., Besarab A.N., Sokolov Y.A., Shapa L.N. Odessa National Polytechnic University Odessa, Ukraine
  Abstract: The article considers the problem of development of power loss minimization system in asynchronous motors with asymmetric voltage supply. The subject of the research is a continuous run of asynchronous motor based on artificial adjusting of characteristics in the area of nominal slipping with better energy indicators than at a operational segment of natural mechanical characteristics. The artificial control characteristic of a drive corresponding to power loss minimization mode is calculated in advance using the solution of extreme control concern. The paper demonstrates that under conditions of electric drive supplied by an asymmetric voltage source the one should apply a phase-by-phase control. The feedback action logic is as follows: reduction of the output voltage of thyristor converter and motor currents as a reducing of the load on the asynchronous motor shaft occurs. As a result, there appears the possibility to maintain the load angle equality of all the phases of asynchronous motor to an optimal value. This allows to solve the problem of power loss minimization in an asynchronous motor due to the load angle equality to the optimal value, and the problem of symmetrization due to the load angle equality in motor phases. The most significant result of the research is the developed automated scheme of symmetrization which is not only efficient with power source voltage asymmetry, but also with asymmetry of asynchronous motor parameters themselves. The proposed functional scheme of microprocessor control and the algorithm of control increase the possibilities of automated loss minimization system.
  Keywords: : electric drive, asynchronous motor, thyristor converter, system of control, power losses, voltage asymmetry, symmetrization.
DOI: 10.5281/zenodo.3239133
4 The Information System of Mass Notification in Emergency Situations with an Algorithm of Optimization of Evacuation Plans Based on the Client — Server Architecture
Authors: Arutiunian V.E. Zaporizhzhya Institute of Economics and Information Technologies Zaporizhzhya, Ukraine
  Abstract: The purpose of this article is to develop a modern information system for mass notification. The system must take into account the disadvantages of all existing systems. The aim has been achieved by the development and implementation of the program complex of an algorithm for construction the effective evacuation plans based on the client-server architecture. The complex, in addition to the server and client parts, also uses the Google Maps services. Today, a lot of information systems for the mass notification of the population have been developed. An analytical review of some of them revealed a number of disadvantages related to the efficiency of the systems, the ability to effectively distribute the population to evacuation points or shelters. A feature of the program is an innovative approach for calculation of an effective evacuation plan for each victim, which has not been presented previously. To find an effective path, three parameters are important, i.e., distance; the available spaciousness of the emergency shelter; and speed. Thanks to the algorithm, it is possible to calculate the optimal path for each victim individually, adjusting the distance depending on the speed and fullness of the shelter. The path found will not always be the shortest, but it will be effective for the uniform filling in of the shelters. The effectiveness of the algorithm is presented in the models we programmed in the AnyLogic program. The use of the evacuation model was analyzed using both a short path and the developed algorithm to calculate the most efficient path. The simulated situations show the possibility of saving more people.
  Keywords: information systems, client-server architecture, interactive maps, mobile applications, mass notification, emergency situations, and AnyLogic program.
DOI: 10.5281/zenodo.3239138
5 Estimation of the Effect of External Information on Participants of Web- Communities by IT-Tools under Conditions of Behavioral Economy
Authors: 1Kravchenko Olga V., 2Danchenko Elena B., 3Bedrii Dmytro I., 4Marunych Valerii S. 1Cherkasy State Technological University, 2«KROK» University, 3State Enterprise “Ukrainian Scientific Research Institute of Radio and Television”, 4National Transport University 1Cherkassy, 2Kyiv, 3Odessa, 4Kyiv, Ukraine
  Abstract: The issues concerning the decision making by a person under the effect of the external information are considered. The authors classify the directions of the existing research. The aim of the study is to analyze the degree of the effect of the external information on a participant of the web-community when making a decision. The aim was achieved with the help of the developed system for collecting and analyzing information in accordance with the rules of the behavioral economics. For the collection and throwing of the necessary information the bot is responsible. The authors expanded and introduced such concepts as: "participant of the web-community", "price of opportunity"," HindSight bias", "expected utility", "utility graph" for the IT sphere. A mathematical model based on the method of analogies of interphase interaction problems is constructed. The structure of the data analysis system of the participants of the web-societies is described with the help of which the collection and processing of data takes place. A useful utility graph is constructed. The most important result in assessing the influence of the external information on the formation of the member’ own decision of the web community is that the average value of interest support under the influence of the negative information, from the viewpoint of the subject, increased insignificantly, whereas under the influence of the positive information it has grown substantially. The significance of the results was that the approach developed by the authors can be the basis for construction of new models and methods for forecasting the result of the effect of the external information.
  Keywords: web community, information, effect of information, rules of behavioral economics, analogy method, IT data analysis system, bot interlocutor.
DOI: 10.5281/zenodo.3239144
6 Separate Analysis of Informational Signs in Multi-Parametric Combined Patterns Recognition Systems
Authors: Zakhozhay O.I., Menyaylenko A.S. , Lyfar V.A. Volodymyr Dahl East Ukrainian University, Severodonetsk, Ukraine Luhansk Taras Shevchenko National University, Starobelsk, Ukraine
  Abstract: The objects for analysis in multi-parametric combined patterns recognition systems are repre-sented by several patterns with different nature of origin. This allows to increase the number of informative signs and the classification reliability. However, there is a negative aspect – increas-ing the time complexity of the data analyze. The aim of the study is reducing the time complexi-ty of data analysis and decision making in multi-parametric combined pattern recognition sys-tems. Well known solutions to this problem: data processing algorithms complication, boosting algorithms using and install more productive computing systems. However, more promising is use an approach that takes into account signs informativity level and decision-made occur does not across the entire data set. For achieve the aim of the study is being solved important scientific problem – developing the new method separate analysis of information signs in multi-parametric combined patterns recognition systems. This method is based on the fact, that in the multi-parametric combined patterns recognition systems the object is represented by a set of patterns which have a different nature of origin. Therefore, in the case of correct classification, all pat-terns from the totality allow to relate the object to the same class. The patterns of recognition object are compared until one or several of them is made a decision on the classification. In such an approach a full analysis of all signs is not carried out, which reduces the time complexi-ty of the recognition process and, as a result, the classification decision-making process speed up.
  Keywords: recognition, classification, patterns, decision-making support, time complexity.
DOI: 10.5281/zenodo.3239140
7 Formal Model for Checking the Interoperability between the Components of the IoT System
Authors: Timenko A.V.1, Shkarupylo V.V.2, Oliinyk A.O.1, Hrushko S.S.1 1 Zaporizhzhia National Technical University Zaporizhzhia, Ukraine 2 National University of Life and Environmental Sciences of Ukraine Kyiv, Ukraine
  Abstract: The objects for the analysis in multi-parametric combined patterns recognition systems are represented by several patterns with different nature of origin. This allows increasing the number of informative signs and the classification reliability. However, there is a negative aspect, namely, increasing the time complexity of the data analysis. The aim of the study is to reduce the time complexity of the data analysis and decision making in multi-parametric combined pattern recognition systems. The well-known solutions of this problem are as follows: the data processing algorithms complication, boosting algorithms use and installation of more productive computing systems. However, more promising is an approach that takes into account the informativity level of signs in the case when the decision is not made using the entire data set. The novelty of the work consists in developing the new method of separate analysis of informative signs in multiparametric combined patterns’ recognition systems. This method is based on the fact that in the multiparametric combined patterns’ recognition systems the object is represented by a set of patterns, which have a different nature of origin. Hence, in the case of a correct classification, all patterns from the totality allow us to relate the object to the same class. The patterns of the object identified are being compared to each other as long as one (or several) of them is not classified. This approach does not use a complete analysis of all signs, which reduces the time complexity of the recognition process and, as a result, the classification decision making process speeds up.
  Keywords: recognition, classification, patterns, decision making support, time complexity.
DOI: 10.5281/zenodo.3239196
8 The Method for Determining the Internal Complex Resistance of a Source to Obtain Maximum Power from an Active Multi-Pole
Authors: Busher V. V., Glazeva O. V. Odessa National Polytechnic University, National University «Odessa Maritime Academy» Odessa, Ukraine
  Abstract: The study of the active multipoles, whose individual circuits are connected in the form of a star, was conducted. The aim of the research is to determine the conditions for obtaining maximum power under the load. The solution is found using the principle of a superposition and an analytical search for an extremum in an active DC three-pole. It is ensured that the necessary condition is the equivalence of the active resistance of the source and the load in each branch, regardless of the electromotive force of the source. It is based on a special symmetry of partial differential equations – in each equation the resistance of the branch of the sources is summed up with the resistance of the same branch of the load. The scientific novelty of this work consists in the analytically accurate substantiation of the condition for achieving the maximum power for an n-phase AC network with the isolated neutrals – full resistances in each branch of the load must be equivalent to conjugate complex resistances of a source. A new method for the experimental determination of internal resistances of both of a three-phase and n-phase source of electrical energy is proposed. It is based on the selection of conjugated complex resistances of the load and the source. The procedure consists of two stages: ensuring the voltage resonance in each phase of a multipole and iterative selection of the resistance of the load in each phase to obtain the maximum power. The MULTISIM model can be used in virtual laboratory works for the study of the electrical engineers.
  Keywords: maximum of active power in load, active three-pole DC, active multi-pole AC, partial differen-tial.
DOI: 10.5281/zenodo.3239194
9 Distributed Knowledge Base System
Authors: Kulykovska N. A., Timenko A. V., Ilyashenko M. B., Kirichek G. G. Zaporizhzhya National Technical University. Zaporizhzhya, Ukraine
  Abstract: . One of the main problems of any distributed system is the analysis of the properties of the ob-tained data and their further use for logical reasoning. To achieve this goal and accelerate the processing time is necessary in the first phase of the system for the development of the intellec-tualization control data. The creation of efficient and adaptive distribution can significantly speed up the processing velocity. Thus, the relevant direction of the research is distributed knowledge based systems. The goal of the work was the models of the distributed knowledge based systems and methods for structuring the system. The novelty of the work consisted in the identification of the main artifacts of a distributed knowledge based system. The formal model of the system consisted of a set of ontologies; lots of services; a set of events that describe the processes of the system; semantic service; a set of composite services and knowledge base. In the system under study, the semantic web technologies were used to examine the data, their pro-cessing and inference. The completeness and effectiveness of the system was determined by a multitude of ontologies. The main difference in the distributed knowledge based systems was the use of the service approach and ontologies in knowledge engineering. In this case, three methods for structuring the system have been proposed. The time spent for publishing the ser-vice in each method is different, but the complexity of the provider is also different.
  Keywords: distributed system, knowledge engineering, data, ontology, service, semantic service.
DOI: 10.5281/zenodo.3244818
10 Analysis and Evaluation of Competence of Information Sources in Problems of Intellectual Data Processing
Authors: Krisilov V. A., Komleva N. O. Odessa National Polytechnic University Odessa, Ukraine
  Abstract: The issues of work related to solving problems of intellectual data processing is to increase the efficiency of qualimetry, classification, diagnostics, choice, decision making, forecasting, tax-onomy, etc., using data mining algorithms and a statistical approach. The aim of the work is to formalize the description and analysis of the source data as a means of improving the quality of solving intellectual problems. Compared with the well-known works, in which the emphasis was placed on certain informational criteria, the approach proposed in the work allows to form a set of quantitative and qualitative criteria for the formalization of information sources. To achieve the goal, taking into account the knowledge of the structure and context of the problem, objec-tive requirements imposed on the input information have been formulated. To ensure the speci-fied quality of solving the problems of intellectual data processing, it is necessary that the input information be objective, reliable, relevant, complete, timely, understandable, etc., and have a certain degree of accuracy, which is possible only with competent experts. The paper considers the concept of single and group expertise. The dependence of the quality of the solution of the data processing problem on the requirements for the source data is considered by the example of the forecasting problem. The accuracy of forecasting the results of external independent estima-tion in the selected section on the degree of completeness of the initial data and the selected methods of data processing and analysis is analyzed.
  Keywords: building models, intellectual tasks, competence, quality of the solution, the properties of the input data, forecasting.
DOI: 10.5281/zenodo.3239185
11 Ways to Reduce the Resistance Torque During the Disk Rotor Spinning and to Increase the Electromotive Force in the Transverse Magnetic Flux Generator in No-Load Mode
Authors: Yehorov A.V.1, Duniev O.O.1, Masliennikov A.M.1, Stamann M 2 1National Technical University «Kharkiv Polytechnic Institute» Kharkiv, Ukraine 2Otto von Guericke University Magdeburg Magdeburg, Germany
  Abstract: The article reviews the transverse magnetic flux machine designs. The work aim was the analysis of the transverse magnetic flux generator with a disk rotor, the stator poles optimal number selection and the resistance torque reducing. This resistance torque was created by one-sided magnetic attraction force from the permanent magnets on the rotor and it hasn’t been considered previously, which is a novelty of this work. The ways to increase the electromotive force in the generator are also considered. The main work goal was obtained by magnetic system analysis of generator using Ansys Maxwell software and disk rotor strength analysis using ASCON Компас-3D software. It is concluded that the magnetic reversal frequency of the stator cores depends on the number of permanent magnets on the rotor. The dependence of the magnetic induction average value in the U-shaped stator core on their number was obtained during the magnetic analysis. The disk rotor strength simulation allowed getting the maximum possible bend of the disk rotor under the influence of the one-sided magnetic attraction force. The neodymium permanent magnets help to improve generator efficiency and to decrease its mass-dimensional indicators. It was proposed to use an uneven permanent magnets distribution on the rotor in the transverse magnetic flux generator to reduce the resistance torque of the disk rotor. The permanent magnets attraction force that interacts with stator steel poles was considered. The dependence of magnetic attraction force of the permanent magnets on the air gap size of the generator has been obtained.
  Keywords: resistance torque, electromotive force, transverse magnetic flux generator, disk rotor, permanent magnet, force of one-sided magnetic attraction.
DOI: 10.5281/zenodo.3239164
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