Кафедра електричної інженерії (ДМетІ)

Permanent URI for this communityhttp://crust.ust.edu.ua/handle/123456789/14624

ENG: Department of Electrical Engineering (Dnipro Metallurgical Institute, DMetI)

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    Mathematical Model of Subpopulation Dynamics in Case of Different Niches for Subpopulations
    (MECS Press, Hong Kong S.A.R., China, 2026) Kuzenkov, Olexandr; Tryputen, Mykola; Kuznetsov, Vitaliy V.; Huliesha, Olena; Artemchuk, Viktor V.
    ENG: The article presents a model of dynamic processes occurring in non-isolated populations that differ in their habitat and mode of nutrition. The results of theoretical studies carried out on the basis of this model show the decisive influence of the ratio of the coefficients of inter-subpopulation competition on qualitative changes in the behavior of the system and individual subpopulations. This ratio is also the main factor influencing the formation of the dominant subpopulation in the system. It has been shown that the system-wide dynamics of subpopulation processes significantly depends on the reproductive potential of all subpopulations and on the mass fraction of individuals that, according to their phenotypic properties, are related to the parents. In this case, the mass fractions of individuals (transition coefficients) must correspond to the condition of closed system and be in specified intervals. It has been established that subpopulations in real life can exchange descendants, which, in turn, can significantly affect the numerical and qualitative aspects of the dynamics. Using the example of a two-dimensional system, the relationship between the sum of the main elements of the transition coefficient matrix and the mutual dependence of subpopulations, as well as their transition to qualitatively different levels, is shown. The bifurcation properties of the model of subpopulation dynamics with a Lotka–Voltaire type function in basic quality have been studied. An approximate justification of possible bifurcations of the system allows us to evaluate the factors that qualitatively influence the dynamics of the system and develop a number of recommendations to prevent the occurrence of catastrophes and collapses in the system.
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    Modeling of Structural Elements of the Energy-Economic Model «Electric Network - Electric Consumer»
    (ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2024) Tryputen, Mykola; Kuznetsov, Vitalii V.; Kovalenko, Viktor; Artemchuk, Viktor V.; Levchenko, Serhii
    ENG: Early evaluation of the parameters of electric power quality and maintenance of the corresponding operating modes of electric facilities in work environment is the important scientific and practical task. In terms of real operating conditions, electric mains often demonstrate nonsinusoidal mode characterized by the available harmonics of voltage and current. Deterioration of the electric power quality in the electric supply systems for industrial enterprises results in the decreasing reliability and efficiency of the operation of energy consumers, i.e. asynchronous motors (AM). The known methods to reduce negative influence of low-quality electric power on the AM operation differ with their integration costs and expected economic effect. Nevertheless, the available methods for the selection of protective means for asynchronous motors, operating in the electric mains with nonsinusoidal voltage, have no economic substantiation. Moreover, economic losses of an industrial enterprise due to the operation of asynchronous motors in terms of considerable deviation of the power quality values from the standard ones have not been analyzed to the full extent. The chapter of monograph has shown that currently it is expedient to solve a task of the selection of AM protective means basing on the computational studies, which involve a simulation model representing the interaction of company electric main with the power consumers. There are following structural elements of a simulation model: a generator of linear voltages of the company electric main; a nonlinear electromagnetic and thermal model of an asynchronous motor; and a decision-making block. The chapter of monograph demonstrates the ways to increase reliability of the modeling of electric main parameters.