Перегляд за Автор "Kuievda, Yulia"

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Comparative computational analysis of the selection of battery energy storage for civil objects and parking with photovoltaic plants
(2022) Zinkevych, Petro; Baliuta, Serhii; Kuievda, Yulia
Energy production from PPS has a number of advantages and disadvantages. One of the disadvantages is that PPS does not produce electricity at night, so they cannot support the load of consumers. To solve the problem of stability of electricity supply at night battery energy storage (BES) are used [1]. BES in combination with a solar power plant is called a battery energy storage system (BESS). This system absorbs and releases energy in different periods. There is no doubt that the additional investment and operating costs of BESS will affect the cost-effectiveness of the PPS.
Fatigue damage of turbine shafts of sugar plants at asynchronous connections of turbogenerator to the power network
(2013) Kuyevda, Valery; Bovsunovskyy, Anatoly; Kuievda, Yulia; Shtefan, Yevgenii
The increase of durability of power equipment of sugar plants is the actual problem. One of the important component part of this problem is the torsional vibration of turbine shafts caused by the action of the reactive electromagnet moments which arise at asynchronous connections of turbogenerator to the power network. In some cases the torsional vibration of turbine shafts leads to theirs essential fatigue damage. The calculations of fatigue damage of most strained parts of the turbine shaft at forced torsional vibration were executed with the ANSYS software (modal analysis).
Forecasting the electricity generation of photovoltaic plants
(2021) Kuievda, Yulia; Baliuta, Serhii; Zinkevych, Petro; Stoliarov, Oleksandr
It was calculated the table of dependence of RMSE, MAE and NMAE errors on the number of input membership functions and their forms for training, test and the whole sample. The number of input membership functions varied from 2 to 30, and the type of membership functions was chosen from the set (MATLAB notation): gbellmf, gaussmf, gauss2mf, trimf, trapmf, dsigmf, psigmf, pimf. To determine the optimal number and form of membership functions, the NMAE error of the test sample was used, which was calculated to be in the range from 3.92% to 4.15%. A minimum was achieved on 5 triangular trimf membership functions. The model was tested for sensitivity to the error of the input data using the chosen optimal number and the form of membership functions. A generated random sequence was added to the input data, which added an NMAE error of 1.81% to 8.19% to the input data. The NMAE error of the initial data in the test sample varied from 4.19% to 5.78%, i.e. the model studies showed a sufficiently low level of variation in the output values relative to the error of the input data.
Fuzzy logic energy management system of food manufacturing processes
(2020) Baliuta, Serhii; Kopylova, Liudmyla; Kuievda, Yulia; Kuyevda, Valery; Kovalchuk, Olena
Introduction. The research is conducted to justify the method of increasing the efficiency of electrical power use in food production processes, which is based on the algorithms of fuzzy power management system. Materials and methods. The study is based on optimal and fuzzy control methods, such as Mamdani and Sugeno algorithms. Computer simulation was performed using MATLAB Simulink. Results and discussion. The control criterion of power supply of food production is formulated in the form of a functional minimization problem, which depends on the expected value of active and reactive power losses, active and reactive power losses at the level of secondary substations and individual load nodes. Maintaining energy efficient voltages in the power supply system nodes is chosen as a control task. It is determined the dependence of energy efficient voltages on the nominal voltage of the power system, the active resistance of its segments, the power and the coefficient of linearized static load characteristics at the network nodes, the equivalent active resistance, the nominal power, open circuit and short circuit losses of secondary substation transformers. To solve the control problem, an algorithm is synthesized using fuzzy controllers at the levels of the primary and secondary substations. In particular, it is determined that the input signals of the secondary substation fuzzy regulator should be the deviation from the energy efficient voltages and the rate of voltage change, and the output signals should be the transformer voltage and the actuation delay. Using numerical methods it is shown that this algorithm can reduce electricity losses in food production processes up to 7% compared to classical voltage regulation methods. Conclusions. The fuzzy system method under study ensures that energy-efficient voltage levels are maintained at the distribution network nodes when the voltage of the power source or the consumer loads are changed.
Identification of mathematical model of turbine generator unit in presence of uncertainty
(2021) Baliuta, Serhii; Chernenko, P. O.; Kuyevda, Valery; Kuievda, Yulia
An identification procedure of mathematical model of turbine generator unit in the presence of uncertainty is studied for using in the interconnected robust control automated system. The procedure is based on “worst-case” identification approach. The controlled object is modelled by the matrix transfer function with additive uncertainty. The identification consists of two stages: first is to identify transfer function with nominal parameters with the use of prediction error minimization algorithm, second – to determine weight function in additive uncertainty model using finding the worstcase log magnitude curve of uncertainties. Identification is performed in active way, determining datasets for each control channel from individual experiments. A linear frequency-modulated signal is selected as the input test disturbance. A simulation model of the controlled object is constructed and the numerical experiment is conducted using the identification procedure.
Magnetic drum separator for removal of ferromagnetic impurities from sugar
(2013) Kuyevda, Valery; Danyluk, Valery; Kuievda, Yulia
This separator has specific pole geometry for creating high gradient of magnetic field and itsconcentration on the working area surface for providing sufficient forces of removing even low magnetic contaminants from the sugar flux. The rotation of the drum creates the conditions for guaranteed removal offerromagnetic impurities in the discharge zone, where the magnetic field is absent. Separation qualitycomplies with current standards.
Recycling and disposal of lithium-ion batteries
(2024) Zinkevych, Petro; Baliuta, Serhii; Kuievda, Yulia
The development of green energy, electric vehicles, and comprehensive recycling of resources are critical aspects on the way to sustainable development, considering that the energy crisis and environmental security are two problems that need immediate solutions (Liang et al., 2021). The transition to renewable energy sources can ensure the end of the fossil fuel era. Electrochemical storage systems, particularly lithium-ion batteries (LIBs), are key technologies to successfully implement this transition (Brückner, Frank, & Elwert, 2020). First introduced to the commercial market in the 1990s, LIBs have gained rapid adoption and have become one of the fastest growing technologies in energy storage. The main advantages of these batteries are high energy and power density, high reliability and long service life. A total of approximately 10.5 trillion watt-hours of EVs are projected to be generated by 2030, of which electric vehicles (EVs) will account for 77%. The duration of service of LIBs depends on their application in various areas. Typically, in consumer electronics, the life of a LIB is 1-3 years, while for more powerful applications, such as energy storage, this life is usually 8-10 years. Used LIBs contain significant amounts of valuable metals such as lithium (Li), cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), copper (Cu) and aluminum (Al). Due to the rapid increase in the production of LIB, the prices of these metals are increasing sharply, in particular for strategic cobalt, the price of which has increased four times in the last two years - from 22 dollars per kilogram to 81 dollars. Therefore, the used LIB should be considered as waste containing valuable strategic materials, taking into account the principles of sustainable development. To date, developed countries are actively demonstrating successful experience in solving the problem of processing spent sources of electricity by implementing a state policy on environmental protection. However, there are currently no regulatory acts in Ukraine that would regulate the process of dealing with used LIBs. Ukraine should develop a regulatory and legal framework that provides for the responsible attitude of both producers and consumers to used LIBs. It is necessary to organize the collection and logistics of the used LIB to the places of their further processing and to raise the environmental awareness of citizens, emphasizing that the separate collection of waste is the only way to achieve a clean environment. It is also important to inform citizens about the harmful effects on health of throwing batteries into landfills together with household waste
Synthesis of robust interconnected power system stabilizers for turbine generators in sugar factories
(2017) Kuievda, Yulia; Baliuta, Serhii
This research aims to develop the method of synthesis of interconnected robust power system stabilizer (IRPSS) for power supply systems of sugar factories with own turbine generators. A model of power supply system with own generator, automatic exciter regulator, turbine and speed governor is constructed. The controlled object nonlinear differential equations model is linearized and simplified by reducing of its order using Schur's method. The model is extended with chosen weighting functions preparing for H∞ synthesis procedure. The LMI region is chosen in the form of a conic sector for satisfying condition of lower oscillability of transient process, which is the main goal of such a regulator to optimize turbine generator operation process. The IRPSS for extended model was synthesized, using H∞ synthesis procedure with poles placement. The regulator is presented in the form of matrix continuous transfer function. The transition process of 3-phase short-circuit fault behind the transformer and subsequent automatic re-closing is simulated with full-order nonlinear model with IRPSS and compared with standard system stabilizer and the system without stabilizer. The graphs of modelled transients demonstrate effectiveness of IRPSS.
The farming costs (including insurance) of the agricultural holdings in the European Union
(2023) Arych, Mykhailo; Kuievda, Yulia; Dvořák, Marek; Hinke, Jana
The paper is devoted to exploring the farming costs (including insurance) indicators of the agricultural enterprises in the European Union. The analysis employs the box plot methodology that provides a five-number summary for a set of data. In this paper, we analyse the evidence of interconnection between the indicators of efficiency and competitiveness and insurance costs regarding food market security. This research discusses the dynamic changes of the absolute value of farming costs (including insurance) indicators and different relative indicators derived from the original one for the agricultural enterprise holdings in the European Union for the period of 2004-2019. The results show that farming costs (including insurance) indicators of the agricultural holdings should be considered as an instrument for providing food market security. Based on these research results, we are going to further explore the impact of insurance on the food market security. In addition, these research results could help to clarify the difference between EU countries and dynamic changes in farming costs (including insurance) indicators of agricultural holdings. У статті досліджено показники витрат на ведення сільського господарства (включаючи страхування) сільськогосподарських підприємств у Європейському Союзі. Під час аналізу використовується методологія прямокутної діаграми, яка надає зведення з п’яти чисел для набору даних. У цій статті ми аналізуємо докази взаємозв’язку між показниками ефективності і конкурентоспроможності та витратами на страхування. У статті обговорюються динамічні зміни абсолютного значення показників витрат на ведення сільського господарства (включаючи страхування) та різних відносних показників, отриманих сільськогосподарських підприємств у Європейському Союзі за період 2004-2019 рр. Результати показують, що показники витрат на ведення сільського господарства (включаючи страхування) агрохолдингів слід розглядати як інструмент забезпечення безпеки продовольчого ринку. На основі цих результатів дослідження ми збираємося продовжити дослідження впливу страхування на безпеку продовольчого ринку. Крім того, ці результати дослідження можуть допомогти з’ясувати різницю між країнами ЄС та динамічними змінами показників витрат на ведення сільського господарства (включаючи страхування) сільськогосподарських угідь.