Кафедра "Електротехніка та електромеханіка" <br>(в 2013 році злиття кафедри "Теоретичні основи електротехніки" та кафедри "Автоматизований електропривод")

Permanent URI for this communityhttp://crust.ust.edu.ua/handle/123456789/1925

ENG: Department "Electrical Engineering and Electromechanics" in 2013 the Merger of the Departments
"Theory of Electrical Engineering" and "Automatic Electric"

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The Impact of Connecting a Wind Power Plant on Emergency Modes of a Traction Substation of an AC Traction System
(Springer, Cham, 2022) Kachan, Yurii; Kuznetsov, Vitaliy V.; Bondar, Oleh I.
ENG: Among the countries of South-Eastern Europe, Ukraine has the greatest technical potential for the implementation of renewable energy sources, and the main part of it is wind power engineering. The traction power supply system of the railways in Ukraine can become an important transiter and consumer of electricity generated by wind power plants. At the same time, the task of ensuring traffic safety and uninterrupted power supply of traction loads requires a preliminary study of the influence of the connected wind power plant capacity on the growing short-circuit currents in the distributive units of the traction substation to which the specified connection is planned. This paper proposes a way to implement such prediction based on a systematic approach, in which a traction substation and an integrated wind power plant are considered as a single electrical-engineering complex, the sources of which work to power the short-circuit point. In previously published studies, the authors usually consider the processes in renewable energy sources and in the traction power supply system separately, without taking into account the mutual influence. The analysis of processes in the short-circuit mode is proposed to perform according to the equivalent circuits for the specified electrical-engineering complex developed by the authors with various possible options for connecting a wind power plant using mathematical modeling with proven methods of theoretical electrical engineering. The peculiarity of the study presented in this paper is also the use of the multiplication factor of the short-circuit current as a criterion for assessing the impact of the power of the connected wind power plant on the short-circuit currents of the traction substation. In our opinion, the coefficient applied by us more clearly characterizes the specified influence in comparison with operating values or complex sizes of short-circuit currents.
Modeling of Wind Speed Distribution in Urban Environment for the Application of Wind Energy Potential Estimation: Case Study
(UIKTEN, Serbia, 2025) Mykhailenko, Oleksii; Karabut, Nadezhda; Doskoch, Volodymyr; Burtseva, Olena; Kuznetsov, Vitaliy V.; Tsvirkun, Sergij; Kolomits, Hanna
ENG: When designing wind farms, the first stage is always an assessment of the target area wind energy potential. It is necessary to have a mathematical description of the wind speeds occurrence probability at the wind turbines potential location to do this. An analysis of relevant studies shows that the most effective approach to obtaining such dependencies is when the wind speed is taken as a random variable. In this case, wind speed distribution in the target area can be modeled using continuous probability distributions. This article is devoted to determining the typical probability distribution models for representing wind conditions in certain areas of the Dnipropetrovsk oblast (Ukraine), which can be used to estimate expected level of power generation by wind power plants. To obtain the data, a series of wind speed measurements were taken at three locations throughout the year. After that, frequency wind speed distributions with ranges of 0.2, 0.5, and 0.8 m/s were created from the obtained dataset and then approximated by continuous probability distributions. Frequency distributions were modeled by Weibull, Rayleigh, Nakagami, gamma, normal, log-normal, generalized extreme value, Birnbaum-Saunders, Wald and Rice continuous distributions. To determine the parameters of each type probability distribution, which is the most relevant to the frequency distribution, the maximum likelihood estimation method was used. To assess the accuracy of the models, the Pearson test, coefficient of determination and normalized root mean square deviation are used. The probability distributions quality is also evaluated graphically using Q-Q plots. The best fit to wind speed frequency distributions demonstrated by the Weibull probability distributions. A slightly lower accuracy was provided by the normal, Rice and Nakagami distributions than Weibull distribution. But in some cases, these distributions have even smaller error than the last one. Therefore, after detailed analysis and validation, they can also be used. The Rayleigh distribution had the worst accuracy, the Pearson test for it rejected the null hypothesis that the probability distributions correspond to the frequency distributions at all three locations. Additionally, the effect of the frequency distribution wind speed grouping range on the quality of maximum likelihood estimation of continuous distribution parameters was analyzed. It showed that the approximation accuracy decreases with increasing range.
Scientific Basis of Analysis and Synthesis of Optimal Energy-Efficient Control of Electromechanical Systems
(ScientificWorld-NetAkhatAV, Karlsruhe, Germany, 2024) Voliansky, Roman; Kuznetsov, Vitaliy V.; Doskoch, Volodymyr; Tkalenko, Oleksandr
ENG: The authors' achievements in the field of development of control systems theory, where high-order sliding modes are implemented, was presented. Original methods for optimizing the accuracy of automatic - control systems for electric drives with nonlinear activation functions were outlined. The dynamic and static characteristics of control systems with nonlinear control algorithms were considered, and their stability was analyzed. For scientific and technical workers engaged in the research, design and operation of modern automatic control systems, as well as for students and post-graduate students of relevant specialties.
Study of Short Circuit Currents in a Distributed Traction Power Supply System with Renewable Electric Power Sources
(IEEE, 2022) Kuznetsov, Valeriy; Kuznetsov, Vitaliy V.; Bondar, Oleh I.; Rojek, Artur; Hubskyi, Petro V.; Stypulkowski, Piotr
ENG: The problems of changing short-circuit currents in a distributed traction system for using renewable energy sources were analyzed in the article. Literary sources analysis shows a further tendency for increasing the share of renewable energy sources in the total energy balance of the country and a particular increase in electricity consumption by electric traction. Goal. The main goal of the study is a method development with its practical application to impact estimation of power-boost points that connected to the traction network with energy using from renewable sources on short-circuit currents values. Methodology. The method that has developed in this study is based on well-known approaches for equivalent circuits of electrical equipment definition, but elemenst pair like «solar panel - inverter» it reproduces as EMF with equivalent resistance, which significantly simplifies further calculations. Results. The study results show that the application of power-boost points will not lead to a significant increase of short-circuit currents in the traction network even if the power of photovoltaic sources will be comparable with the power of existing converting units on traction substations. This is because of the physical nature of the photovoltaic panel and its power mode which usually closer to the current source with high internal resistance. Practical value. This also allows us to conclude that in most cases from the point of view of changing the short circuit currents the integration of power-boost points that are powered by solar power plants is quite possible with operating sections of the traction power supply system.