Dissertations / Theses on the topic '621.315:004.032.26'
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Hinchcliffe, Claire. "Processing and properties of nanocomposite dielectric films." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437011.
Full textSubsingha, Wanchai. "Analysis and control of the advanced static var compensator for normal and abnormal operating conditions in power systems." Thesis, Northumbria University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416348.
Full textZhou, Xiaohang. "Fabrication and study of prototype supercapacitors with conducting polymers and advanced carbons." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582569.
Full textIbrahim, Ahmed Abdel-Mordi. "A practical method for capacitor voltage balancing of diode clamped multilevel inverters." Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/2020.
Full textMcAneney, J. "Characteristics of thin and ultrathin film ferroelectric capacitor structures." Thesis, Queen's University Belfast, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432670.
Full textLookman, Akeela. "Phase transition behaviour and metastability in barium strontium titanate thin film capacitors." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426708.
Full textPatel, Dimple. "Carbon nanofibres for use in supercapacitors." Thesis, Loughborough University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479012.
Full textAdams, Timothy B. "Barrier layer capacitors based on CaCu₃Ti₄O₁₂." Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/10520/.
Full textKulsangcharoen, Ponggorn. "Characterization and emulation of a new supercapacitor-type energy storage device." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13143/.
Full textКатюха, Ігор Анатолійович. "Прогнозні моделі електричних навантажень розподільчих мереж в умовах невизначеності вихідної інформації." Thesis, Таврійський державний агротехнологічний університет, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31033.
Full textThe thesis for getting scientific degree of the Candidate of technical science on the specialty 05.14.02 «Electric power stations, network and system» (141 Electrical energetics, electrical engineering and electromechanics). – Tavricheskiy State Agrotechnology University, Melitopol, Ukraine National Technical University «Kharkiv Polytechnic Institute» MES of Ukraine, Kharkiv, 2017. The dissertation devoted to solving actual scientific and technical problem of development of modern science and analytical tools forecast electricity consumption in the face of uncertainty, taking into account the possibility of information support automated systems of commercial accounting of electric power and features of individual consumers and aims to increase efficiency and save electricity. Improved method of fuzzy regression analysis to build long–term forecasting models of electric loads in distribution networks. Included balanced participation of two performance criteria fuzzy models: the degree of combination and degree of fuzziness when building predictive models. The method of correction term predictive models for short–term forecast. An approach to building the type of predictive models in any type of stress. Analytical contacted fuzzy indicators forecast accuracy Mean absolute percentage error. The technique was tested in the development of predictive models of electric load number of consumers with different types of load charts. The main results of the dissertation found practical application in the form of hardware and software to automate the process of long–term and operational forecasting electricity consumers of electrical loads that can integrate information into an automated accounting system of electricity, as well as operational management mode of distribution networks. VII As a result of the research on the theme of the thesis, the following scientific results were obtained: - the method for obtaining predictive models of electrical loads is improved, which is distinguished by constructing a fuzzy regression compatibility criterion based on the intersection of fuzzy numbers, which makes it possible to uncover the uncertainty of the output data and improve the quality of the prediction of electrical loads. - for the first time the method of unification of the type of forecasting models is proposed, which differs in the fact that in the daily schedule of electricity consumption allocated functional areas, with the separate use for them of fuzzy regression analysis, which allows you to get the kind of forecast models at all loads. - for the first time the method of increasing the adequacy of models obtained on the basis of fuzzy regression analysis, which differs from the parity considering the degree of compatibility and the degree of fuzzy description, which will make prediction of electrical loads more qualitative. - for the first time an analytical method for determining the efficiency of the forecast of electricity consumption in electric networks is determined, which allows to perform a comparative analysis of fuzzy regression models of the forecast with models obtained by other methods. The practical significance of the obtained results of work for the electric power industrylies in the developed method of forecasting electricity consumption based on fuzzy regression analysis, which includes the principles of constructing predictive models, algorithmic support, as well as software implemented in a convenient for integration in AMSCA form. The research results are implemented and confirmed by the relevant acts: - PE "Molokozavod-OLKOM" for the analysis of electricity consumption and operational control in order to reduce energy losses in the network of intra-electric power supply. VIII - in the educational process, the main results of the work are included in the relevant disciplines - "Practical engineering training" and "Engineering activities" in the specialty: 8.10010101 - Power engineering of agricultural production. - Azov REM OJSC "Zaporizhiaoblenergo" used a hardware and software complex for the process of long-term and short-term prediction of electrical loads and operational control of the modes of distribution networks. The basic scientific positions on the materials of the dissertation work are published in 15 printed works, including 9 articles in the scientific professional editions of Ukraine (5 in the publications included in the international science-computer bases, 1 ¬ in the edition with the index SCORUS), 6 in the materials of the conferences and workshops. Thesis consists of introduction, abstract, four sections, conclusions, list of used sources and applications. The total volume of the dissertation is 190 pages, among them: 18 figures in the text, 20 tables in the text, the list of used sources contains 115 titles in 12 pages, applications in 19 pages.
Катюха, Ігор Анатолійович. "Прогнозні моделі електричних навантажень розподільчих мереж в умовах невизначеності вихідної інформації." Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31032.
Full textDissertation for scientific degree of candidate of technical sciences, specialty 05.14.02 – electric power stations, networks and systems. – Tavricheskiy State Agrotechnology University, Melitopol, 2017. The dissertation devoted to solving actual scientific and technical problem of development of modern science and analytical tools forecast electricity consumption in the face of uncertainty, taking into account the possibility of information support automated systems of commercial accounting of electric power and features of individual consumers and aims to increase efficiency and save electricity. Improved method of fuzzy regression analysis to build long–term forecasting models of electric loads in distribution networks. Included balanced participation of two performance criteria fuzzy models: the degree of combination and degree of fuzziness when building predictive models. The method of correction term predictive models for short–term forecast. An approach to building the type of predictive models in any type of stress. Analytical contacted fuzzy indicators forecast accuracy Mean absolute percentage error. The technique was tested in the development of predictive models of electric load number of consumers with different types of load charts. The main results of the dissertation found practical application in the form of hardware and software to automate the process of long–term and operational forecasting electricity consumers of electrical loads that can integrate information into an automated accounting system of electricity, as well as operational management mode of distribution networks.
Авдєйонок, Ірина Ігорівна. "Фотонна інтегральна схема для систем з штучним інтелектом." Master's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/41180.
Full textThe dissertation is devoted to the development of a photonic integrated circuit for a neural network. Integrated circuits are an integral part of modern technology. Most of the functional units can be replaced by a photonic component (diodes, waveguides, filters and amplifier) to create a photonic integrated circuit. Photonic integrated circuits have several advantages: they have a higher speed of processing and transmission of information, a larger bandwidth and less energy loss. The most common is the use of hybrid circuits, namely part of the elements of the integrated system is integrated by photonic elements. The first section is devoted to the study of modern development of neural networks. Hardware implementations of neurons and neural networks are considered. A patent search for neuronal modeling was also performed. The second section considers modern architectures of the photon integrated circuit. A new structure of the integrated circuit and its manufacturing technology were proposed. For this purpose, the structure of the lithographic installation was proposed and the technical task was formulated. The third section is devoted to the design of the lithographic system. Dimensional calculations, calculation of structure of optical system were carried out. After the design, the system was analyzed, namely the optimization of the calculated system, energy calculation, and aberration analysis. The fourth section examines the Hopfield neural network, its mathematical model. Based on which a program was developed to model the Hopfield network and calculate weights. The fifth section is devoted to experimental research. A prototype of a photonic integrated system was developed. Experiments were performed: the study of the waveguides of the system for their further implementation and the study of the current prototype. The sixth section is devoted to the development of a startup project.
Robert, Kévin. "Vers la fabrication collective de micro-supercondensateurs à électrodes interdigitées à base de nitrure de vanadium déposé en technologie couche mince." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1I082/document.
Full textThe mobile connected devices have a prominent place in our everyday life but energy autonomy is limited. Thus, the development of efficient and miniaturized energy storage devices is an expanding field. The performance of these systems depends on the used electrode materials and the electrolyte. This thesis is focused on the fabrication of micro-supercapacitors with interdigitated electrodes composed of sputtered vanadium nitride (VN) thin films. The modulation of the deposition parameters allows densifying the thin films in order to increase their electrical conductivity or, on the contrary, leads to the synthesis of porous thin films to increase the surface capacitance. X-ray absorption spectroscopy of VN thin films tested in aqueous KOH in operando configuration coupled with surfaces analyses (XPS/ ToF-SIMS) show that the high capacitance of the VN is due to the presence of thin layer of vanadium oxide at the VN surface. Micro-supercapacitors reporting state-of-art performance in interdigitated or face/face topologies were fabricated using optimized VN films: the film thickness was varied to increase the energy density. The Atomic Layer Deposition of VN layers was also achieved in the frame of this study in order to ensure the formation of thin layers on high specific surface area 3D substrates. Finally, different ionic liquids have been tested as electrolyte, the purpose being solid electrolyte formation based on ionogels technology
Pastre, Aymeric. "Élaboration d’électrodes à base de films d’or nanoporeux et conception de micro-supercondensateurs intégrés." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10187/document.
Full textThe thesis work aims at the design of nanoporous gold-based all-solid state micro-supercapacitors, integrated on a silicon substrate. In a first step, we have developed a process for the formation of gold films by auto-catalytic chemical reduction. In order to enhance the adhesion of the gold film to the silicon substrate, an original seed layer was produced by a sol-gel process. It consists in a thin film of zirconium oxide (ZrO2) doped with gold nanoparticles. The porosity of these gold films was controlled by a templating method using polystyrene microspheres (Ø ≈ 20 nm). Nanoporous gold films can reach a 1.2 μm thickness in the absence of delamination. The porosity is completely interconnected and the pore size (20 nm) was chosen in order to be compatible with the used electrolyte. The method only involves wet chemistry processes and is fully compatible with conventional micro-manufacturing processes. The nanoporous gold films constituting the electrode material of the micro-supercapacitor have been structured by photolithography in the form of interdigitated combs. The impregnation of a gelled polymer electrolyte (PVA / KOH) made it possible to finalize the manufacture of the all-solid state micro-supercapacitor. Electrochemical characterizations show that the micro-device reaches a surface capacitance of 240 μF/cm² at 20 mV/s, and can endure more than 8000 cycles, while losing only 5% of its initial capacitance. These performances are comparable to those of the all-solid state integrated micro-supercapacitors reported in the literature
Li, Min. "Preparation of composite materials for high-performance supercapacitors." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I011.
Full textSupercapacitors, as energy storage devices, have drawn great attention in our daily life to bridge the gap between batteries and capacitors. Therefore, the preparation of high-performance material electrodes for supercapacitors plays a vital role in the future technological developments. In this context, layered double hydroxides (LDHs) and Ni(OH)2 have been recognized as promising electrodes for supercapacitors, owing to their fast redox reaction and battery-type behavior.The Chapter 1 of my PhD work gives a brief historic overview, principles and mechanism of energy storage, electrode materials of supercapacitors and the corresponding characterization methods. In Chapter 2, after a brief introduction on LDHs and their investigation as electrode materials in supercapacitors, we summarize our results obtained on Ni-based LDHs as electrodes for supercapacitors. Firstly, NiFe LDHs on Ni foam (NF) coated with reduced graphene oxide (NiFe LDHs/rGO/NF) was prepared by electrochemical deposition method. NiFe LDHs/rGO/NF achieved enhanced specific capacity (585 C g-1 at a current density of 5 A g-1). Additionally, a flexible asymmetric supercapacitor was assembled using NiFe LDHs/rGO/NF as the cathode and mesoporous carbon (MC) coated on NF as the anode. The supercapacitor exhibited an energy density of 17.71 Wh kg-1 at a power density of 348.49 W kg-1. Secondly, NiAl LDHs coated on carbon spheres (CS) supported by Ni foam (NiAl LDHs@CS/NF) electrodes were synthesized by a facile hydrothermal method. The performance of the prepared materials as binder-free electrodes in supercapacitors was assessed. The NiAl LDHs@CS/NF electrode achieved the largest areal capacity (1042 mC cm-2), as compared to the areal capacity values attained by NiFe LDHs@CS/NF (705.8 mC cm-2) and NiCr LDHs@CS/NF (814.9 mC cm-2) at 1 mA cm-2. Therefore, a hybrid supercapacitor device comprising NiAl LDHs@CS/NF as the positive electrode and N-doped reduced graphene/NF as the negative electrode was assembled, which attained an energy density of 43 μWh cm−2 at a power density of 0.805 mW cm−2. The hybrid supercapacitor was successfully applied to operate a windmill device continuously for 32 s. Finally, NiMnCr LDHs-carbon spheres modified Ni foam (NiMnCr LDHs@CS/NF) nanocomposite was prepared using a two-step hydrothermal process and exhibited a high specific capacity of 569 C g-1 at 3 A g-1 with good reversibility and stability. Furthermore, a hybrid supercapacitor was fabricated using NiMnCr LDHs@CS/NF as the positive electrode and FeOOH coated on NF (FeOOH/NF) as the negative electrode. The energy storage device reached an energy density of 48 Wh kg-1 at a power density of 402.7 W kg-1. In Chapter 3, Ni(OH)2@CuO@Cu foam binder-free electrodes were fabricated by a two-step process at room temperature with various deposition times (30, 50, 90, 150 and 200s). Among all the samples, Ni(OH)2@CuO@Cu-150 exhibited the largest areal capacity of 7063 mC cm-2 at 20 mA cm-2, and was therefore chosen as the positive electrode in a hybrid supercapacitor. Using N-doped reduced graphene oxide on nickel foam (N-rGO/NF) as the negative electrode, a hybrid supercapacitor was assembled. It displayed good flexibility, cycling stability and high areal energy density of 130.4 μWh cm−2 at a power density of 1.6 mW cm−2.In conclusion, all the results obtained in this thesis imply the promising potential application of Ni-based hydroxide composites as energy storage devices and provide valuable highlights to the exploration of new composite materials for supercapacitor electrodes in future works (Chapter 4)
Zhang, Yuan. "Prepartion of multi-metal sulfides for electrochemical supercapacitors." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I014.
Full textIn recent years, electrochemical supercapacitors (ESs), as environmentally-friendly energy storage systems, are facing several challenges associated with the performance, functionality, and durability of key materials. Among different types of ESs, hybrid supercapacitors, the combination of electrodes with different energy storage mechanisms, especially the combination of electrochemical double layer capacitance (EDLC) and battery-type behavior, are expected to offer enhanced electrochemical performance. Concerning hybrid supercapacitors consisting of EDLC//battery-type electrode materials, carbonaceous materials, owing to their excellent electrical conductivity, electrochemical stability, and large specific surface area, are the most promising candidates for electrode materials with EDLC-type behavior. For electrode materials with battery-type behavior, owing to the faradaic charge transfer reactions involved in the electrochemical process, transition metal compounds can store plenty of energy and represent one of the most promising candidates for electrode materials with battery-type behavior. In this thesis, different carbonaceous materials, such as reduced graphene oxide (rGO), porous reduced graphene oxide (PrGO), and poly-ethylene dioxythiophene-Fe-900 (PF-9), are prepared through chemical oxidation and reduction methods. Moreover, transition metal compounds, such as CoS/carbonaceous support (rGO or PF-9), ZnCoS, ZnS/Ni3S2 and Sb2S3/CoS2/CrOOH, are synthesized via chemical co-precipitation and ion-exchange method. A variety of different techniques, including XPS, SEM, ICP-AES, TEM, XRD, BET, and Raman, are used to investigate the physicochemical performance of as-prepared materials. Their corresponding electrochemical performance is also evaluated through a 3- electrode system. Additionally, hybrid supercapacitors consisting of as-prepared carbon and transition metal electrodes are assembled, respectively, and their electrochemical performance is evaluated through the 2- electrode system
Карпишин, Ростислав Арсенович, and Rostyslav Karpyshyn. "Розробка проекту фотогальванічної ферми." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2021. http://elartu.tntu.edu.ua/handle/lib/36390.
Full textУ даній кваліфікаційній роботі проведено аналіз факторів які впливають на ефективність фотогальванічної ферми. Запропоновано методики для розрахунку ресурсів ресурсів сонячної радіації та дослідження впливу взаємного затінення на втрати потужності фотогальванічної ферми. Проведено розрахунок режиму роботи, визначено оптимальний кут нахилу сонячних панелей. На основі чого було вибрано модель та необхідну кількість інверторів та обладнання для передачі електроенергії. Проведено розрахунок електричних втрат.
In this qualification work the analysis of the factors influencing efficiency of a photovoltaic farm is carried out. Methods for calculating solar radiation resources and studying the effect of mutual shading on the power loss of a photovoltaic farm are proposed. The mode of operation is calculated, the optimal angle of inclination of solar panels is determined. Based on which the model and the required number of inverters and equipment for electricity transmission were selected. The calculation of electrical losses is carried out.
ВСТУП 5 1 АНАЛІТИЧНА ЧАСТИНА 8 1.1 Фотоелектричні елементи та їх види 8 1.2 Технічні характеристики фотоелектричних модулів 11 1.3 Основні характеристики інвертора для фотогальванічної системи 13 1.4 Аналіз факторів, що впливають на потенціал фотогальванічної ферми 16 2 ПРОЕКТНО-КОНСТРУКТОРСЬКА ЧАСТИНА 18 2.1 Методи для розрахунку ресурсів сонячної радіації 18 2.2 Розрахунок режиму роботи сонячної електростанції 21 2.3 Вибір розташування фотоелектричних модулів сонячної електростанції 24 2.4 Вплив затінення на групу сонячних панелей 24 2.5 Дослідження впливу взаємного затінення на втрати потужності фотогальванічної ферми 30 2.6 Розрахунок виробітку електроенергії з урахуванням взаємного затінювання фотоелектричних модулів 35 3 РОЗРАХУНКОВО-ДОСЛІДНИЦЬКА ЧАСТИНА 42 3.1 Розрахунок кількості фотоелектричних модулів 42 3.2 Розрахунок кількості інверторів 47 3.3 Вибір елементів для внутрішньої мережі фотогальванічної ферми 51 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 57 4.1 Заходи захисту при роботі з електроустановками 57 4.2 Інженерні норми проектування об’єктів енергетики 61 ЗАГАЛЬНІ ВИСНОВКИ 63 ПЕРЕЛІК ПОСИЛАНЬ 64
Гаврілов, Владислав Сергійович. "Система прогнозування музичних композицій методами машинного навчання." Master's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/46611.
Full textMaster’s thesis explanatory note: 81 p., 35 fig., 20 tables, 1 appendixes, 10 sources. The object of the research is to create a computer tool that allows you to automatically generate realistic music compositions. In the course of the work an analysis of existing methods and approaches to solve this problem was carried out. Out of all analyzed were selected the most realistic results and can be implemented using available computing resources. The subject of the research is a neural network system that allows to generate new music based on submitted compositions, taking into account the duration of the sound of the notes and the pauses between them. The purpose of the work is to generate tunes of a certain genre and style for further use in amateur projects, where developers do not have the ability or finances to create their own or buy existing ones. Several compositions were generated for demonstration purposes. They allow you to evaluate the advantages and disadvantages of the method used. In the course of the work, existing solutions to this problem were analyzed, which allowed us to choose the best method and try to improve it.
Пелещак, Іван Романович. "Система розпізнавання мультиспектральних образів на основі осциляторних нейронних мереж." Diss., Національний університет «Львівська політехніка», 2021. https://ena.lpnu.ua/handle/ntb/56753.
Full textArico, Cassandra. "Micro-supercondensateurs à porosité contrôlée pour des applications à forte densité d’énergie sur substrats rigide et flexible." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I055.
Full textContinuous development and further miniaturization of electronic devices greatly stimulate the research for miniaturized and compact electrochemical energy storage (EES) devices, allowing thus the development of autonomous, sustainable and connected devices. Small footprint storage sources should be sufficient efficient in terms of power, autonomy and lifespan and fixed directly on chip. To fulfil the requirements, the combination of a micro-battery (μ-Bat) with a micro- supercapacitor (μ-SC) would constitute an ideal EES microdevice where μ-Bat is dedicated to long-term applications and μ-SC ensures power demand. As promising electrode candidate for high power microdevice, carbide-derived carbons (CDCs) have been identified to load to important capacitance gains. In addition, niobium oxide (Nb2O5) stores higher levels of charges and offers the prospect of achieving energy densities of Li-ion battery materials but with the ability to operate at high power. In the present study, Nb2O5 thin films were deposited on silicon wafer by sputtering and crystallized by a rapid thermal annealing into an orthorhombic phase T-Nb2O5. We investigated porous T-Nb2O5 in which rapid insertion of lithium throughout the entire material. Then, titanium carbide (TiC) thin films were deposited on silicon wafer by sputtering and partial chlorinated into strongly adherent TiC-CDC films. Hybrid micro-supercapacitors CDC/Nb2O5 were successfully prepared and characterized in 1M LiClO4 (EC/DMC : 1/1). Finally, direct laser writing onto KaptonTM of Nb2O5 and carbon-based electrodes open the way for the design of flexible micro-supercapacitors
Данилів, Святослав Романович, and Sviatoslav Danyliv. "Розробка технічних рішень для підвищення енергоефективності потужних світлодіодних світильників." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, кафедра електричної інженерії,Тернопіль, Україна, 2020. http://elartu.tntu.edu.ua/handle/lib/33376.
Full textУ даній кваліфікаційній роботі проведено аналіз схем живлення світлодіодів та методів підвищення коефіцієнту їх потужності. Проаналізовано вплив величини струму та температури на світлотехнічні та енергетичні параметри світлодіодів. Запропоновано експериментальні методики і проведені комплексні дослідження світлодіодів, в яких встановлено ступінь впливу температури p-n переходу та струму на світлотехнічні характеристики світлодіодів. На основі чого визначені режими живлення світлодіодів, для забезпечення кращих техніко-економічних показників. Розроблено математичну модель джерела живлення світлодіодів, та проаналізовано вплив різних параметрів схеми на його характеристики.
In this qualification work the analysis of power supply schemes of LEDs and methods of increase of their power factor is carried out. The influence of current and temperature on lighting and energy parameters of LEDs is analyzed. Experimental methods are offered and complex researches of light-emitting diodes in which the degree of influence of temperature of p-n transition and current on light- engineering characteristics of light-emitting diodes is established are carried out. On the basis of which the modes of power supply of LEDs are defined, for maintenance of the best technical and economic indicators. A mathematical model of the LED power supply has been developed, and the influence of various circuit parameters on its characteristics has been analyzed.
ВСТУП ...5 1 АНАЛІТИЧНИЙ РОЗДІЛ ...8 1.1 Загальні характеристики потужних світлодіодів ...8 1.2 Аналіз схем джерел живлення для світлодіодів ...12 1.3 Аналіз методів підвищення коефіцієнта потужності ...14 1.4 Аналіз впливу температури на світлотехнічні параметри світлодіода ...16 1.5 Аналіз методів підвищення коефіцієнта корисної дії джерела живлення... 19 1.6 Висновки до розділу...20 2 ПРОЕКТНО-КОНСТРУКТОРСЬКИЙ РОЗДІЛ ...21 2.1 Методика і результати вимірювань світлової віддачі світлодіода при живленні імпульсним струмом при різних температурах ...21 2.2 Проблеми нагріву світлодіодів та шляхи їх вирішення ...27 2.3 Проектування радіаторів з оптимальними масогабаритними параметрами...28 2.3.1 Теплова модель ребристого радіатора...29 2.3.2 Оптимізація масогабаритних параметрів радіаторів...32 2.4 Вибір схеми живлення світлодіодного модуля ...35 2.5 Теоретичний аналіз процесів і попередній розрахунок схеми джерела живлення СД ....36 2.6 Висновки до розділу ...44 3 РОЗРАХУНКОВО-ДОСЛІДНИЦЬКИЙ РОЗДІЛ ...46 3.1 Розробка математичної моделі джерела живлення світлодіодів ...46 3.2 Дослідження математичної моделі ...49 3.3 Висновки до розділу ...62 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...63 4.1 Правила техніки безпеки при експлуатації світлотехнічного обладнання...63 4.2 Стійкість роботи об’єктів господарювання...65 ЗАГАЛЬНІ ВИСНОВКИ ...68 ПЕРЕЛІК ПОСИЛАНЬ ...69
Грицик, Назар Вікторович, and Nazar Hrytsyk. "Побудова імітаційної моделі вітроелектричної установки." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, кафедра електричної інженерії,Тернопіль, Україна, 2020. http://elartu.tntu.edu.ua/handle/lib/33374.
Full textУ даній кваліфікаційній роботі виконано розробку імітаційної моделі вітроелектричної установки і в середовищі МАТLАВ\Simulink, для відтворення реальних фізичних процесів з допустим ступенем достовірності. Розроблено блок схеми для моделювання основних вузлів ВЕУ; вітрового колеса, редуктора, асинхронного генератора з короткозамкнутим ротором. Проведено імітаційне моделювання при постійній та змінній швидкості вітру. Визначено основні енергетичні параметри моделі.
In this qualification work, a simulation model of a wind power plant was developed in the MATLAB \ Simulink environment to reproduce real physical processes with an acceptable degree of reliability. The block diagram for modeling of the main units of wind turbines is developed; wind wheel, reducer, asynchronous generator with short-circuited rotor. Simulation at constant and variable wind speeds was performed. The main energy parameters of the model are determined..
ВСТУП ...6 1 АНАЛІТИЧНИЙ РОЗДІЛ ...9 1.1Аналіз енергетичного потенціалу вітру в Україні та в Тернопільській області ... 10 1.2 Типи вітрових електростанцій ...11 1.3 Класифікація вітроустановок ...12 1.4 Конструктивні елементи вітроелектричних установок з горизонтальною віссю обертання ...14 1.5 Особливості експлуатації вітроенергетичних установок ...17 1.6 Висновки до розділу...19 2 ПРОЕКТНО-КОНСТРУКТОРСЬКИЙ РОЗДІЛ ...20 2.1 Обґрунтування вибору програмного забезпечення для розробки імітаційної моделі вітроелектричної установки ...20 2.2 Математичний опис моделі вітрового колеса ...22 2.3 Вибір та розрахунок генератора...27 2.4 Математична модель асинхронної машини в середовищі Simulink...31 2.5 Визначення параметрів асинхронного генератора за даними каталогу. ... 34 2.6 Самозбудження асинхронного генератора ...37 2.7 Вибір редуктора та розробка його моделі ...40 2.8 Висновки до розділу ...43 3 РОЗРАХУНКОВО-ДОСЛІДНИЦЬКИЙ РОЗДІЛ ...44 3.1 Представлення математичної моделі вітроустановки в середовищі МАТLАВ\Simulink...44 3.2 Дослідження роботи вітроустановки при постійних вхідних параметрах...47 3.3 Моделювання роботи вітроустановки при змінних вхідних параметрах ... 50 3.4 Методи оптимального управління ВЕУ за критерієм енергетичної ефективності...52 3.5 Висновки до розділу ...55 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ...56 4.1 Загальні правила безпеки при монтажі вітроенергетичної установки ...56 4.2 Організація цивільного захисту на об’єкті господарської діяльності. ...58 ЗАГАЛЬНІ ВИСНОВКИ ...62 ПЕРЕЛІК ПОСИЛАНЬ ...63
Момот, Андрій Сергійович. "Удосконалення методу визначення характеристик дефектів багатошарових матеріалів за результатами активного теплового контролю." Doctoral thesis, Київ, 2020. https://ela.kpi.ua/handle/123456789/34952.
Full textМірчук, Ігор Анатолійович. "Підвищення експлуатаційних характеристик суднових кабелів за рахунок технологічних режимів охолодження та радіаційного опромінення електричної ізоляції." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2020. http://repository.kpi.kharkov.ua/handle/KhPI-Press/49276.
Full textPh.D. thesis undertaken in research specialization 141 "Electric Power Engineering, Electrical Engineering and Electric Mechanics" (14 – Electrical Engineering). – National Technical University "Kharkiv Polytechnic Institute", Ministry of Education and Science of Ukraine, Kharkiv, 2020. The dissertation is devoted to increasing of the operational properties of shipboard cables due to the technological modes of cooling and electron beam irradiation of insulation and sheath based on modern flame retardant halogen-free polymeric compounds, which provide the necessary complex of electrical, physical and mechanical properties with appropriate control of technological processes. To achieve this, the following tasks were set: – to prove the expediency of gradual cooling of polyethylene insulation of high-voltage power cables to ensure both operational parameters and stability of properties during operation; – to substantiate the application of the method of electro-thermal analogy for the construction of a mathematical model of cooling of insulated conductor taking into account the temperature distribution over the thickness of insulation in a non-constant thermal mode; – to develop a method of calculating the technological parameters of the cooling mode of power cable, based on the calculation of a nonlinear thermal equivalent circuit of insulated conductor in a non-constant thermal mode, taking into account dependence the thermal resistance and heat capacity of the insulation from the temperature by methods of discrete resistive equivalent circuits; – to determine the influence of technological cooling modes on the temperature distribution in the thickness of extruded in sulation and to justify the duration of the transition process, which corresponds to achievement of the same temperature over the entire thickness of power cables insulation various design at different time points, depending on the cooling water temperature; – to verify experimentally the efficiency of detecting technological defects in the design of the power shipboard cable by partial discharges values; – to create a methodology for optimizing the power shipboard cable with coaxial construction to ensure maximum heat flow power dissipation into the environment, which causes an increase in current load, if insulation thermal resistance provided; – to prove the efficiency of the use a protective polymer sheath with high thermal conductive properties to increase the current load of power shipboard cables; – to determine the effect of accelerated electron beam energy on the mechanical and electrical properties of shipboard cables and determine the irradiation coefficient range for insulation which provides an increase of operational characteristics, on the basis of correlation between the electrical and mechanical properties of filled with flame retardants halogen-free compound based on ethylene-vinyl acetate modified by electron beam; – to verify the efficiency of absorbed dose distribution along the perimeter and length of shipboard cables after irradiation according to obtained results of mechanical and thermal tests of polymeric halogen-free flame retardant protective sheath of cable; – to determine the thermal stability of the halogen-free flame-retardant polymeric protective sheath modified by irradiating, on basis of accelerated thermal aging, to predict the service life of shipboard cables and to substantiate the possibility of operation in conditions with high humidity and high operating temperatures for unscreened cable with unscreened twisted pairs and thermoplastic insulation and protective sheath. Object of research – technological modes of cooling and irradiation of electrical insulation of shipboard cables, based on halogen-free filled with flame retardants polyolefin compound. Subject of research – electrical, mechanical and thermal operational properties of the shipboard cables polymer insulation and sheath based on filled with flame retardants halogen-free compounds. Research methods. Theoretical and experimental studies are based on the use of methods of numerical and physical modeling of technological modes of cooling and electron beam irradiation of polymeric electrical insulation and protective sheath of shipboard cables. Methods of theory of non-stationary thermal conductivity to calculation of cooling mode of polymeric cable insulation. Differential equations of thermal conductivity and electrical conductivity. The method of electro-thermal analogies to determine the temperature distribution in the thickness of insulation at different time points, depending on the temperature of cooling water for shipboard power cable. Nonlinear thermal and electrical equivalent circuits of insulated conductor in transient thermal mode. Implicit Euler method and nodal potentials method for obtaining temperature distribution in thickness of cable insulation. A method of optimizing the design of the power cable provided cooling during operation to increase the current load. Thermal balance equation to determining the thermal resistance of insulation during operation. Irradiation crosslinking theory to determine the optimal irradiation dose of polymeric insulation. The theory of thermal aging of insulation to predict the service life of shipboard cables. Approximation of experimental electrical, mechanical and thermal properties of modified by irradiation insulation of shipboard cables. Correlation and regression analysis of electrical, mechanical and thermal properties after modification by irradiation of polymeric insulation and protective sheath of shipboard cables. Partial discharge detection technique in high voltage solid polymeric insulation for defect detection on technological stage of production power shipboard cable. The following scientific results are obtained in the work. The dissertation solves the scientific and practical problem of increasing the operational properties of shipboard cables due to the technological modes of cooling and irradiation of electrical insulation based on modern halogen-free flame retardant polymeric compounds. The mathematical model of technological process of cooling insulated conductor in unsteady thermal mode, by taking into account dependence of thermal and physical characteristics of polymeric insulation from the temperature, for determine the temperature distribution throughout the thickness of polyethylene insulation at different time points depending on water temperature under gradual cooling, has been improved. Mathematical model allows to determine the conditions for ensuring stable characteristics of the shipboard power cable during operation. The criterion for determination of technological parameters of the cooling mode of power shipboard cables, which is the time of the transitional process of cooling the insulated conductor to achieve an equal temperature throughout the thickness of the polymeric insulation, is proposed. The optimum thickness of the polymeric protective sheath on condition of long-term thermal stability of irradiated cross-linked based on polyolefin insulation has been established. It provides a 30 % increase current load of the coaxial design shipboard power cable. The range of irradiation coefficient for halogen free flame retardant insulation of shipboard cables when guarantees increasing electrical resistance of polymeric insulation modified by electron beam more than twice, the breakdown direct current voltage 1,3 times relative to the non-irradiated condition, is determined. The correlation between mechanical and electrical properties of halogen-free based on polyolefin insulation modified by electron beam, depending on the linear velocity of the cable under the electron beam and constant value of electron beam current. The distribution of the absorbed dose along the perimeter and length of the halogen-free flame retardant polymeric protective sheath depending on the technological parameters of the irradiation modes of shipboard cables, is established and allows to determine the irradiation dose for cables, when protective sheath provides increasing the resistance to aggressive chemicals while high physical and mechanical properties is still available. The stability of the cables structure to high temperature and humidity is experimentally proved on the basis of accelerated aging of unscreened cable with unscreened twisted pairs, with thermoplastic polyethylene insulation and protective polyvinylchloride sheath with adequate aging during operation. It allows predicting the service life of shipboard cables depending on the operating temperature. A technique for calculating the technological parameters of the power cable cooling mode by the methods of discrete resistive equivalent circuits has been developed. A technique based on the calculation of a nonlinear thermal scheme of substitution of conductor with polyethylene insulation in a non-constant thermal mode, taking into account the dependence of thermal resistance and heat capacity from the temperature. The proposed methodology and algorithms can be applied to determine the technological modes of cooling cable polymeric insulation without using expensive full-scale experiments, especially important for the new compounds development and cable constructions, as well as modernization available at cable factories equipment for cooling power cable, data cable with twisted pairs, radio frequency and optical cables. The efficiency of determining partial discharges in high-voltage solid insulation has been proved to detect defects at the technological stage of the producing of power shipboard cables, as well as to adjust the technological process of cooling. The methodology for heat transfer in a coaxial design single-core power cable based on criterial equations of natural convection has been developed to optimize the design of the power shipboard cable to ensure the maximum linear density of heat flow dissipated from the cable surface. The efficiency of application of polymeric materials based on micro- and nanocomposites with high thermal conductivity for sheath of high-voltage shipboard cables, providing a 30 % increase in thermal dissipating of power cable, is shown. It is established the energy of accelerated electrons 0.5 MeV provides a higher degree of crosslinking of polymeric halogen-free insulation based on filled with flame retardants compound compared to the energy of 0.4 MeV at the same irradiation coefficient, electron beam current and the number of wire passages under electron beam. It is established an increase of tensile strength, electrical insulation resistance and breakdown DC voltage of crosslinked polymeric halogen-free insulation with irradiation coefficient 5-7 m/(mА∙min) with constant value of elongation at break not less than 120 % which ensure a compromise between rigidity and flexibility of the shipboard cable. It is established an increase in 1,5–2 times the time of reaching the critical parameter – elongation at break of the modified by electron beam polymeric sheath based on a halogen-free compound compared to the same thermop lastic non-modifying sheath. It is an increase service life of the shipboard control cable at maximum operational temperatures in 1,5–2 times. The materials of the dissertation are used at the educational process Department of Electrical Insulating and Cable Technique of National Technical University "Kharkiv Polytechnic Institute" at education bachelors and masters in disciplines of specialty "141 – Electric Power Engineering, Electrical Engineering and Electric Mechanics" (specialization "141.04 Electrical Isolating, Cable and Fiber-Optic Technique"), at "Azov Cable Company" (Berdians'k) at development and determination of optimal technological parameters of production modes of halogen-free, flame retardant shipboard cables, Association "Ukrelectrocable", in PJSC "Yuzhkable Works". Dissertation work was performed at the PJSC "Ukrainian Scientific and Research Institute of Cable Industry" (Berdians'k) and Department of Electrical Insulating and Cable Technique of National Technical University "Kharkiv Polytechnic Institute" (Kharkiv) according to research programs of PJSC "Ukrainian Scientific and Research Institute of Cable Industry" (PM EIUV.505.564–2018 "The research of thermal stability of the sheath cable SPOVEng-FRHF 12x2,5 before and after exposure under electron beam", PM EIUV.505.584–2019 "Determination of the quantity and distribution of the absorbed dose after irradiation of the sheath of shipboard flame retardant cables") wherein the applicant was one of the program developers and executor of individual sections.
Καρατζάς, Χρήστος. "Σύγκριση δυναμικής συμπεριφοράς του σύγχρονου αντισταθμιστή και του στατικού αντισταθμιστή αέργου ισχύος (SVC)." Thesis, 2012. http://hdl.handle.net/10889/5651.
Full textThe current thesis was held during the period 11/2011-9/2012 within the research activities of the Generation, Transmission, Distribution and Utilization of Electric Energy Laboratory, Department of Electrical and Computer Engineering, University of Patras, under the supervision of Professor Gabriel B. Giannakopoulos. The purpose of this study is to compare the dynamic performance of a conventional synchronous condenser and a static reactive power compensator (SVC) on an installed electrical grid, simulating different cases affecting the process of reactive power compensation and voltage support at the network’s load buses. This thesis includes representation of the mathematical model of the conventional synchronous condenser and the inductive parameters that characterize it, the different excitation system models used and the Park Transformation. Regarding the static VAR compensator (SVC), this thesis also refers to the fundamentals of TCR and TSC control, the explanation of the current-voltage characteristic and the analytic description of the control system’s components, such as the voltage regulator, the synchronization system and the gate-pulse generator. Lastly, for the modeling and simulation of both compensators and the installed electrical grid, the simulation program used is PSCAD / EMTDC because of its usability and reliability on a wide range of energy projects.
Федірко, Юрій Андрійович, and Yurii Fedirko. "Моделювання електричних та теплових характеристик підземних кабельних ліній електропередач." Master's thesis, 2020. http://elartu.tntu.edu.ua/handle/lib/33209.
Full textУ дипломній роботі розроблено математичну модель для розрахунку електромагнітних та температурних характеристик кабельних мереж з врахуванням їх способу прокладання. Розроблена математична модель дозволяє враховувати теплові втрати в екранах з врахуванням способу заземлення. Проведено моделювання електромагнітних та температурних характеристик кабельних ліній з зшитого поліетилену, та розраховано величину струмового навантаження. Визначено залежність температури кабелю в холодну та теплу пору року в залежності від його температури.
In the diploma work the mathematical model for calculation of electromagnetic and temperature characteristics of cable networks taking into account their way of laying is developed. The developed mathematical model allows to take into account heat losses in screens taking into account the grounding method. Modeling of electromagnetic and temperature characteristics of cross-linked polyethylene cable lines is carried out, and the value of current load is calculated. The dependence of the cable temperature in the cold and warm seasons depending on its temperature is determined.
ЗМІСТ ВСТУП ...…6 1 АНАЛІТИЧНИЙ РОЗДІЛ ...9 1.1Загальні положення і стан проблеми прокладання силових кабелі ...9 1.2 Теплофізичні характеристики матеріалів ...13 1.3 Електричні характеристики кабелів ...15 1.4 Джерела втрат енергії в кабельних лініях ...17 1.5 Висновки до розділу. ...18 2 ПРОЕКТНО-КОНСТРУКТОРСЬКИЙ РОЗДІЛ ...20 2.1 Розрахунок параметрів кабелю ...20 2.2 Двостороннє заземлення екранів ...24 2.3 Одностороннє заземлення екранів ...26 2.4 Транспозиція екранів ...31 2.5 Висновки до розділу ...34 3 РОЗРАХУНКОВО-ДОСЛІДНИЦЬКИЙ РОЗДІЛ ...35 3.1 Постановка задачі для розрахунку навантажувальної здатності кабельних ліній ...35 3.2 Математична модель електромагнітних процесів ...37 3.3 Розрахунок електромагнітних характеристик ...39 3.4 Математична модель теплових процесів в підземних кабельних лініях ...41 3.5 Чисельне дослідження впливу різних умов теплообміну на температурне поле в кабельному каналі ...43 3.6 Дослідження температурного поля в кабельному колекторі ...48 3.7 Висновки до розділу ...55 4 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ56 4.1 Заходи електробезпеки при роботі з електрообладнанням...56 4.2 Норми проектування інженерно-технічних об’єктів господарювання.60 ЗАГАЛЬНІ ВИСНОВКИ ...62 ПЕРЕЛІК ПОСИЛАНЬ ...63