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Автор: Grafiati
Опубліковано: 30 травня 2022
Оновлено: 31 травня 2022

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1

Меркотан, Роман Андрійович. "Захист проводів повітряних ліній електропередавання від галопування та ожеледно-вітрових навантажень". Master's thesis, Київ, 2018. https://ela.kpi.ua/handle/123456789/23285.

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Магістерська дисертація складається з пояснювальної записки на 106 сторінках та графічної частини на 8 листах. В роботі наведено 46 рисунків та 13 таблиць. Робота містить такі розділи: 1. Загальні відомості щодо ожеледно-вітрових навантажень та коливань проводів ПЛ. 2. Моделювання коливань проводів ПЛ з урахуванням ожеледно-вітрових навантажень. 3. Методи та засоби захисту ПЛ від вібрації та галопування. 4. Методи та засоби захисту ПЛ від ожеледно-вітрових навантажень. Актуальність роботи: Одним з найголовніших принципів сучасної енергетики є забезпечення надійної та безперебійної роботи обладнання електроенергетичних систем і електричних мереж. Для повітряних ліній електропередавання одним з актуальних є питання їх захисту від зовнішніх впливів природного походження, таких як вітрові та ожеледно-вітрові навантаження. У зарубіжних країнах немає єдиної методики нормування розрахункових кліматичних умов для проведення їх районування за інтенсивністю ожеледоутворення, тому питання організації боротьби з різними видами відкладень на проводах ліній електропередавання на сьогоднішній день поставлене першочергово і є дуже актуальним. Для швидкого та точного вирішення цього питання необхідним є уточнення всіх існуючих знань та матеріалів щодо вітрових та ожел едно-вітрових навантажень, створення комп'ютерних моделей аналізу та прогнозування даних відкладень на проводах ліній електропередавання і створення нових методів та типів захисту ліній електропередавання від впливів природного походження Мета дисертаційної роботи: Аналіз і вивчення повного циклу виникнення ожеледних відкладень на лініях електропередавання з врахуванням впливу дії вітру, аналіз впливу та створення комп'ютерної моделі ожеледно-вітрових навантажень на проводи ліній електропередавання, запропонування методик та типів захисту ліній електропередавання від ожеледно-вітрових навантажень. Об’єкт дослідження: проводи повітряних ліній електропередавання усіх класів номінальних напруг. Предмет дослідження: процес виникнення ожеледних відкладень під дією вітру та їх вплив на проводи ліній електропередавання усіх класів номінальних напруг. Ключові слова: проводи ліній електропередавання, ожеледні відкладення, ожеледоутворення, ожеледно-вітрові навантаження, захист від ожеледно-вітрових навантажень.
The master's dissertation consists of an explanatory note on 106 pages and graphic part on 8 paper. There are 46 pictures and 13 tables. The work contains the following sections: 1. General information on ice-wind loads and fluctuations of wires. 2. Modeling of fluctuations of wires of the power lines, taking into account the ice-wind loads. 3. Methods and means of protection of the submarine from vibration and galloping. 4. Methods and means of protection of submarines from ice-wind loads. Actuality of work: One of the most important principles of modern energy is to ensure reliable and uninterrupted operation of equipment of electric power systems and electric networks. One of the most urgent issues is to protect them from external influences of natural origin, such as wind and ice-wind loads. In foreign countries there is no uniform method of normalization of the calculated climatic conditions for their zoning based on the intensity of ice-forming, so the issue of organizing the fight against various types of deposits on the lines of transmission lines has been put to the fore today and is very topical. In order to quickly and accurately resolve this issue, it is necessary to clarify all existing knowledge and materials concerning wind and ice-wind loads, to create computer models of analysis and forecasting of these deposits on wires of power transmission lines and to create new methods and types of protection of transmission lines from natural influences. The purpose of the dissertation work: Analysis and study of the full cycle of occurrence of iced deposits on transmission lines, taking into account the influence of the wind, impact analysis and the creation of a computer model of ice-wind loads on the transmission lines, offering methods and types of protection of transmission lines from ice-wind loads. Object of research: conducting of overhead transmission lines of all classes of nominal voltages. Subject of research: the process of occurrence of iced ice deposits under the influence of wind and their influence on conduction lines of electric power transmission of all classes of nominal voltages.
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2

Polycarpou, Alexis. "Identification of voltage sag indices in electrical power systems." Thesis, University of the West of England, Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432326.

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3

Zhou, Xiaohong. "An optimal wavelet-based algorithm for noise rejection in PD measurement." Thesis, Glasgow Caledonian University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443224.

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4

Gomes, Eli Eber Batista. "Operational Optimisation of Gas Turbines Distributed Generation Systems in Competitive Electricity Market." Thesis, Cranfield University, 2007. http://hdl.handle.net/1826/3246.

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The development of power generation technologies and the deregulation of the power market has led to an increasing interest in distributed power generation, mainly the simultaneous exploitation of electricity and heat from the same energy source, known as combined heat and power (CHP) systems. As a consequence of the high competitiveness of power markets and increasing environmental concerns, distributed power generators have to make reasonable choices at multiple levels of complexity. A key issue to successfully approaching these problems is the development of decision making support tools that rely on service life prediction, intelligent economic dispatch optimisation techniques and condition monitoring. This research introduces the concept and development of a decision making support tool for a mini-pool nerve centre based on distributed gas turbine generation units operating in a competitive market. The nerve centre framework leads naturally to a multi-criteria optimisation problem which is solved in this research with a hybrid genetic algorithm adapted priority list and creep life assessment. The proposed hybrid approach can result in a significant saving to generators as it efficiently optimises mini- pool profits and service hours between failures in an acceptable computation time and accurately. Life cycle assessment combined with generation schedule optimisation can enhance the maintenance strategy activities and the competitiveness of gas turbine distributed generation plants, particularly for generators trading energy in a highly competitive market. Gas turbine combined heat and power distributed generators are unlikely to succeed in competing individually with centralised generation technologies within the present market framework, but they can be more competitive in an information technology based mini-pool. Additionally, results show that the development of a low carbon emission power industry can result in an outstanding opportunity for combined heat and power mainly in power markets currently highly dependent on coal and oil powered stations.
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5

Messina, Marco. "Secondary particulate formation from solid fuel power plant." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420599.

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6

Yao, Jilong. "Assessment of the topology and control of three-level inverters for low-voltage distributed generation." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433506.

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7

Hutchison, Graeme. "Non invasive parameter identification of power plant characteristics based on recorded network transient data." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1293.

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Synchronous generators are the most widely used machines in power generation. Identifying their parameters in a non invasive way is very challenging due to the inherent nonlinearity of power plant performance. This thesis proposes a parameter identification method using particle swarm optimisation (PSO) for the identification of synchronous machine, excitation system and turbine parameters. The PSO allows a generator model output to be used as the objective function to give a new, more efficient method of parameter identification. This thesis highlights the effectiveness of the proposed method for the identification of power plant parameters, using both simulation and real recorded transient data. The thesis also considers the effectiveness of the method as the number of parameters to be identified is increased, and the effect of using differing forms of disturbances on parameter identification.
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8

Xia, Yuanye. "Multi-terminal current source based DC transmission system for multiple wind turbine interfacing." Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=16837.

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This thesis focuses on using power electronic techniques to addresses grid integration for wind energy conversion systems. Different approaches to mitigate the low frequency generator torque ripple caused by diode bridge rectifiers are proposed. The advantages and disadvantages of the methods are discussed. A relationship for maximum power point tracking is theoretically analysed. Based on this relationship, two new maximum power point tracking techniques are proposed, which show benefits over conventional tracking methods. Then a pulsewidth modulated current source converter based parallel connected wind energy conversion system is investigated. A new inverter controller for this system is proposed, which is able to maintain a constant average DC network voltage to give satisfactory system performance whilst controlling output reactive power. Practical results support the presented simulations. Furthermore, a fault ride through scheme is proposed for the current source converter based system. The protection scheme uses a shunt resistive chopper to dissipate the active power during faults, and allows the inverter to supply reactive power to support the grid. The space vector modulation for the current source inverter is modified for this application and the design of the dumping resistor is discussed. The system shows riding through capability to both AC and DC network disturbances. This aspect is substantiated by simulation.
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9

Ge, Yi. "Application of damping torque analysis in large-scale power systems." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602514.

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The technique of damping torque analysis (DTA) is proposed on the basis of linearized Philips-Heffron model of a single-machine infinite-bus power system. Analysis is to examine the electric torque contribution from a particular source to the electromechanical oscillation loop of generator in the power system. An effective engineering method - phase compensation method - for the design of PSS was developed on the basis of DTA. In study of real large power systems, modeling of the whole power system is very complicated. The generators in the large power system and other equipments result in a very high order of system model. Therefore a proper simplification method has to be applied to reduce the high order of real large power system. The aim of system simplification is to reduce the order of the linearized model of the large power systems, maintaining the characteristics of the under studied low frequency. Power system stabilizers (PSSs) have been adopted to mitigate low-frequency oscillations in the grid. However, in concerning of efficiency of damping controller in the power systems, decomposed analysis of PSS is studied to be further evidence for selecting installing location of PSS in the power systems. With greater integration of wind turbine generators in the introduced realistic large-scale power systems, impact of doubly fed induction generators (DFIGs) has been investigate for further study of renewable energy connected power systems. In terms of coordinated design of PMU and PSS in real large-scale power systems, developments in communication systems have made it feasible to also use remote signals as PSS inputs provided by PMU units. So as to the selection of signals from multiple locations can be further improved..
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10

Cai, Hui. "Enhancement of power system dynamic stability using electric vehicles and distributed generation." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.602450.

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This thesis proposes a method to establish the accurate parameters of stabilisers in the context of power systems with increasing penetration of Doubly Fed Induction Generators (DFIGs), Solid Oxide Fuel Cells (SOFCs) and Photovoltaic (PVs) using a hierarchical coordinated strategy and localised design. The performance of the tuned stabilisers is verified using modal analysis results and non-linear simulation. This thesis proposes that by using regulated stabilisers, the dynamic stability of a power system with large-scale Distributed Generation (DG) integration can be maintained. SmartParks have been proposed in published literature to support emergent electric vehicle charging. In practice, a SmartPark can be configured as an adjustable load, in charging mode, or a regulated generator, in a discharging mode using a voltage control strategy. In this thesis, damping torque analysis (DTA) has been used to investigate the impact on dynamic stability of the joint operation of SmartParks in power systems with conventional synchronous machines. The analysis reveals that in terms of the local damping ratio, optimal charging and local capacity is best considered during SmartPark design. According to a Phillips-Heffron model developed for a multi-machine system with SmartPark, active and reactive power stabiliser can be incorporated into the SmartPark control loops to improve the damping of the system. Finally, this thesis considers the economic operation of micro-grids by proposing a combined EV charging/discharging model which incorporates stochastic uncertainties in vehicle travel patterns and initial battery state of charge (SOC). The model includes provision of energy storage and renewable generation infeed is used to establish an economic basis for micro-grid operation based on market revenues.
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11

Zhong, Xiaotao. "Charging methodologies for distribution network with distributed generation." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501811.

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In the past distribution networks are passive as there are no generation sources connected to them. The direction of power flow is normally from the high voltage network down to the distribution network. More and more distributed generations (DG) are now connected to distribution networks and this has changed them to become active. As a result the pricing of the use of distribution system has become more complex and it is a major issue of current interest. The issue concerns the way the cost of distribution services should satisfactorily be allocated among the involved parties due to multi-directional power flow.
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12

Ding, M. S. "Synchronised phasor measurement and islanding operation of distributed generation." Thesis, Queen's University Belfast, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438180.

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13

Ochije, Ndubuisi Kenneth. "Design and control of a high speed flux switching generator for embedded power generation and variable speed application." Thesis, University of Leicester, 2005. http://hdl.handle.net/2381/30230.

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This research focuses on the design and control of a new class of brushless machine known as the flux switching machine for high speed and high power application. This machine is a hybrid of the inductor alternator and the switched reluctance machine. The characteristic of this machine determined from an experimental generator shows that the power delivery capability of the machine is limited by the synchronous inductance of the machine especially at high speeds. Various power factor control techniques are proposed and evaluated as possible solutions to the attendant problems with the uncontrolled flux switching generator. This involves the use of series compensation and shunt compensation techniques. For the series compensator technique, a new class of series line compensation delivering controlled power factor using pulse width modulation is identified and tested on an experimental flux switching generator system. The shunt compensation technique for the flux switching generator system is a controlled rectifier, which uses phase angle pulse width modulation to deliver controlled power factor. The power factor control of the flux switching generator system shows that significant improvement in power delivery for the flux switching generator system can be achieved. Matlab/Simulink models are developed for each of the proposed technique and the results compared with experimental data shows reasonable agreement. These Matlab/Simulink models can now be effectively used for rapid design and prototyping of the flux switching generator system. Closed loop control of the output voltage of the flux switching generator system can be achieved. This is done using field current control and/or armature current control. The increased controllability of the FSG compared to other reluctance machines makes it a viable alternative for high speed, high power applications especially in mechanically harsh environment.
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14

Ma, Xiandong. "Wavelets for partial discharge denoising and analysis." Thesis, Glasgow Caledonian University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404617.

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15

Anaparthi, Krishna Kumar. "Measurement based identification and control of electromechanical oscillations in power systems." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/8452.

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16

Bolam, Robert. "Multi-phase inverters and anti-islanding techniques in distributed generation." Thesis, University of Newcastle upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433223.

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17

Clarke, Joseph Andrew. "Contributions to the design and deployment of clean, efficient energy systems." Thesis, University of Strathclyde, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443131.

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18

Polyzakis, Apostolos L. "Technoeconomic evaluation of tri-generation plant : gas turbine performance, absorption cooling and district heating." Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/1832.

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This PhD thesis is a demand led study taking into account changes in ambient conditions and power settings of a tri-generation power plant. Includes an evaluation tool for combined heat, cooling and power generation plant. The thesis is based on an overall technical-economic analysis of the tri-generation system, including: 1. Energy demand analysis and evaluation of actual tri-generation case studies. 2. Modelling of the prime mover (Gas Turbine, GT) 3. Modelling of the absorption cooling system, (LiBr/Water). 4. Economic analysis and evaluation of the entire tri-generation plant. Initially, the main effort is to carry out research concerning the energy demands of different actual cases. The research includes sourcing, collecting, classification and evaluation of the available information. The cases cover a wide range of economic life and the resulting data specifies the energy needs which the purposed tri-generation power plant needs to cover. The second part deals with the prime mover (namely the Gas Turbine, GT) modelling and simulation. The technical part of the assessment includes the Design Point (DP) and Off Design (OD) analysis of the GT. In other words, the performance analysis simulates different thermodynamic cycles (Simple, or with Heat Exchanger), and different configurations (one or two shafts). Also, the computer programming code is capable of simulating the effects of the use of different types of fuel, ambient conditions, part load conditions, degradation, or the extraction of power for district heating or for absorption cooling. The third part includes the simulation of the absorption cooling system alone and/or in co-operation with the prime mover. The simulation is based upon the premise that the original prime mover is replaceable. Finally, an evaluation methodology of tri-generation plants, is introduced taking into account, both technical facts and economic data -based on certain cases from Greek reality- helping the potential users to decide whether it is profitable to use such technology or not. The economic scene will include the basic economic facts such as initial cost, handling and operational cost (fuel prices, maintenance etc), using methodology based on Net Present Value (NPV). This thesis suggests several tri-generation technology modes. The more economic favourable than the conventional technology is the 2-shaft simple cycle mode for the cases of international airport (12MW total power demand) and the isolated island (120MW), while the 1-shaft simple cycle mode is the more economic favourable for the case of hotel (1MW). The main contribution of the thesis is that it provides an intergraded realistic tool, which simulates the future operation (technical and economic) of a trigeneration plant, capable of helping the potential investor decide if it is profitable to proceed with the investment.
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19

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.

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20

Subsingha, 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.

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21

Zhou, 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.

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Climate change, overpopulation and the decreasing availability of fossil fuels require the society to move towards sustainable and renewable resources. It can be anticipated that renewable energies will inevitably replace fossil fules and dominate the world's energy supply system in the long term. In order for these new energy sources to become completely reliable to meet with the growing energy demand, much research effort has been focused on energy storage technologies, especially those realted with electricity, such as supercapacitors. With regards to electrical energy storage devices, supercapacitors could fill the gap between batteries and conventional solid state and electrolytic capacitors. They store electrical energy through double layer charging, faradaic processes, or a combination of both. This thesis deals with the fabrication and study of prototype supercapacitors using conducting polymers and advanced carbons as the electrode materials. The work includes the synthesis of PPy-CNT and PANi-CNT nanocomposites, fundamental and electrochemical characterisations of conducting polymers and advanced carbons, electrode fabrication, and electrochemical performance of prototype supercapacitors. Additionally, this thesis aims to enhance the performance of prototype supercapacitors by improving the electrochemical properties of the existing electrode materials for supercapacitors, optimising the design of unit cells and stacks, and simplifying electrode fabrication.
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22

Ibrahim, 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.

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23

McAneney, 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.

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24

Lookman, 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.

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25

Patel, Dimple. "Carbon nanofibres for use in supercapacitors." Thesis, Loughborough University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479012.

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26

Adams, Timothy B. "Barrier layer capacitors based on CaCu₃Ti₄O₁₂." Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/10520/.

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Calcium-Copper-Titanate (CCTO) is one of a class of non-ferroelectric, highly tilted Perovskite-structured oxides. Theoretical values of permittivity for these materials are low and fairly typical for non-ferroelectrics, yet these materials received considerable attention when reports of extremely high permittivity (in excess of 10,000) emerged, with one study on CCTO published in Science that attempted to assign the unusual behaviour to an as yet unknown exotic polarisation mechanism. This thesis proves that the high permittivity is actually extrinsic in origin and originates from a barrier layer capacitance effect; the measured values for intrinsic permittivity for CCTO and related ceramics was found to be low and comparable to theoretical values.
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27

Prassas, Ilias. "Combustion of pulverised coal in swirl burners." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286343.

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28

Wain, Susan Elizabeth. "Thermal and mechanical properties of pulverised fuel boiler slags." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/8209.

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29

Patel, Rupesh. "Modelling analysis and optimisation of cantilever piezoelectric energy harvesters." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13246/.

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Over the last decade there has been a growing increase in research in the field of vibrational energy harvesting - devices which convert ambient vibrational energy into electrical energy. The major application area for such devices is as power sources for wireless sensors, thereby replacing currently used batteries which suffer from a finite lifespan and pose environmental issues during disposal. The vast majority of designs are cantilever beams comprising of piezoelectric layers having coverage identical to the substrate layer. It is evident from the literature that rudimentary work has been performed on design optimisation, with reliable and extensive parametric studies on geometry, especially piezoelectric layer coverage, being overlooked. As a result of this, outcomes from previous research are yet to be seen in designs for practical applications. In this work a versatile linear model is developed which can accurately predict the performance of cantilever piezoelectric energy harvesters. An integral part of the model uses a transfer matrix method to accommodate the difference in structural dynamics of both uniform and non-uniform structures with model validation provided through extensive experimental work. The linear model developed is used to carry out parametric studies on the geometry of three distinct energy harvester cases thereby providing comprehensive knowledge on key variables and geometrical changes which can improve performance. In one of the cases examined, an improvement in performance of over 100% is predicted by solely altering piezoelectric layer coverage. However, the load resistance, i.e. electrical condition, has a significant effect on the trends in generated power which led to work directed toward harvester optimisation in a more realistic electrical scenario. Investigation on harvester geometry whilst utilising an electrical scenario comprising of an energy storage medium is undertaken in this work. The developed model ensures the effects of electro-mechanical coupling remain and provides a solid basis from which users can readily apply model extensions through inclusion of further electrical components to resemble practical circuitry. Theoretically, for all examined case studies, improvements in performance were realised through alterations to piezoelectric layer dimensions with the most notable result indicating an improvement of over 200% during optimisation of piezoelectric layer length. In conjunction to theoretical findings, outcomes of extensive experimental work are provided in order to highlight the accuracy and reliability of the presented theoretical models in both electrical scenarios. Variation in mechanical damping magnitude plays a pivotal role throughout experimental testing and is one key factor in explaining why devices comprising of shorter piezoelectric layers have high performance. A methodology behind unbiased design comparisons is also provided in this work, and involves comparing devices with identical fundamental frequencies. The reasoning behind this approach is to allow for each device to perform as efficiently as possible in the same excitation scenario. Systematic alterations to multiple geometric parameters are used to achieve this. Geometric parameters such as the substrate thickness are observed to provide adequate frequency control. Using this approach, performance improvements from adjustments to piezoelectric coverage still remain. The occurrence of non-linearity in piezoelectric materials is a widely known phenomena and so lastly, a more robust model is provided which incorporates material and geometric non-linearity. This model is useful in determining dynamical responses of uniform and non-uniform piezoelectric energy harvesters when subjected to moderate-to-high acceleration levels. A thorough validation of the theoretical model is achieved using extensive experimental data obtained from a range of samples. For the harvester composition tested in this work, the occurrence of mild non-linearity at base acceleration levels as low as 1 meter per second squared is witnessed with softening behaviour causing the resonant frequency to decrease with base acceleration. In order to avoid reduced efficiency in the final application, the prediction of possible frequency shifts is vital during the design process.
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30

Zamri, Mohd Y. "An improved treatment of two-dimensional two-phase flows of steam by a Runge-Kutta method." Thesis, University of Birmingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251270.

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31

Dahal, Keshav Prasad. "An investigation into the application of modern heuristic optimisation techniques to problems in power and processing utilities." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248648.

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32

Cheokul, Renu. "Advanced power generation and fuel conversion technologies in the case of Thailand." Thesis, University of Ulster, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268625.

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33

Chan, Wai-Lok. "Integrated monitoring and control for intelligent power substations." Thesis, City University London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312956.

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34

Smith, P. J. "Predicting hot corrosion rates under coal fired combined cycle power plant conditions." Thesis, Cranfield University, 1994. http://dspace.lib.cranfield.ac.uk/handle/1826/10512.

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Type 11 hot corrosion has been identified as a major life limiting factor of gas turbine components in the topping cycle of coal fired combined cycle power plant. Impurities in the coal combustion gases provide the environmental contaminants necessary for type 11 hot corrosion to occur. It is the purpose of the present study to develop corrosion lifting models such that corrosion rates and thus component lives in coal fired combined cycle plant gas turbines may be accurately predicted thus minimising efficiency losses and plant downtime due to corrosion related problems. Type 11 hot corrosion has been shown to follow bi11lodal distributions which cannot be modelled using the well known mathematical models. It has been shown that a probabilistic approach to modelling is appropriate and that the Gumbel Type I extreme value model of maxima can be used to model the maximum extreme corrosion data This is appropriate as it is the maximum extreme corrosion which in life limiting in the plant gas turbine. Basic corrosion data has been generated through a series of laboratory hot corrosion tests designed to simulate the ambient conditions within the plant gas turbine. The variables having most influence on the corrosion process have been identified as ; temperature, thermal cycling, alkali (Na + K) metal sulphate deposition rate, S02 and HCl in the ambient atmosphere. The corrosion models have been developed from this data which accurately predict the type 11 hot corrosion rates observed in the coal fired gas turbine of a combined cycle power plant .
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35

Chrysohoidou, Dimitra. "Studies of alkali vapour removal from hot gases at 650°C by aluminosilicate sorbents." Thesis, University of Surrey, 1996. http://epubs.surrey.ac.uk/843770/.

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Анотація:
New advanced combined cycle coal-fired power generation systems are dependent on improvements in gas turbine technology and the development of hot gas cleaning techniques. These techniques are not only necessary to meet environmentally accepted emission limits for SOx and NOx but also to prevent downstream equipment from corrosion and erosion. Volatile alkali vapours in the exhaust gases produced by either coal gasification or combustion lead to corrosion of the gas turbine blades resulting in reduced operating life. Consequently, alkali removal systems which can operate upstream of the gas turbine have been incorporated into the development of the clean coal technologies. A number of studies on alkali removal systems have been performed in the temperature range of 800°C - 1000°C. Solid aluminosilicates, such as emathlite, activated bauxite, kaolinite and Fuller's Earth, react with alkali vapours at high temperatures and therefore have been characterised as suitable alkali sorbents. Fuller's Earth was identified as potentially the most suitable sorbent for use in the UK at the specified operating temperatures. This material was studied in detail by McLaughlin (1990) for use in a fixed bed configuration within the British Coal Air-Blown Gasification Cycle. Recently, it has been recognised that if ceramic filters are used for the removal of fine particulates, operating temperatures for alkali sorption will have to drop to 400°C-600°C, since these filters fail mechanically at higher temperatures. Much of the alkali will condense under these conditions and be removed by the filtration stages. However, the residual alkali levels may still exceed the revised turbine inlet specification of 24 ppb wt. Hence further studies of alkali sorption are required in this lower temperature region. During this work, it proved difficult to obtain accurate results at temperatures as low as 600°C, because of the low level of vapour phase alkali. However, experiments were performed successfully at 650°C and atmospheric pressure, on the fixed bed sorption rig used previously for tests at 827°C and 927°C. Tests comparing Fuller's Earth and kaolin, showed kaolin to have a higher sorption capacity at this temperature. Fixed bed tests with sodium and potassium were performed with Fuller's Earth pellets. The runs were of 200-600 hrs duration, with 4.58 ppm wt NaCl (1.8 ppm wt Na), 5 %vol H2O and up to 160 ppmv HCl in the inlet gas stream. Alkali uptake profiles were generated from chemical analysis of precise layers of pellets removed from the bed. Extensive modifications and improvements in analytical procedures enabled a closure of the mass balance of >99% to be achieved for a 600 hr run. Alkali exit levels measured using alumina wool filter pads in the exit gas were of the order of 5-6 ppb wt. Fuller's Earth pellets which had been pre-treated in gasifier gas and which were therefore contaminated with carbon, were tested and no difference was observed in their Na characteristics. Element mapping techniques based on Scanning Electron Microscopy, confirmed that a shrinking core model for Fuller's Earth grains and kaolin pellets was appropriate. The 'two-reaction' mechanism proposed by McLaughlin (1990), was used to fit the experimental results at 650°C. Albite was identified by X-ray diffraction studies as the reaction product under high-acid conditions and nepheline under non-acid conditions. Exit gas analysis studies with an on-line monitor for HCl, showed the production of HCl to be directly connected with the presence of NaCl vapour and to increase significantly with the presence of water vapour in the system. However, the detailed reaction mechanism has not been identified yet. The theoretical model developed for the high temperature studies (McLaughlin, 1990), using the pellet-grain model and the 'tank-in-series' method of solution has been applied successfully at 650°C. Parameters were extracted by curve fitting theoretical to experimental Na uptake concentration bed profiles. To test the numerical methods and the Szekely assumptions used in the McLaughlin program, two new computer programs were developed. The first, tested the pellet-grain model for a single pellet and the second was developed to solve the model more rigorously with a variable-order, variable-time-step numerical method. The new fixed bed model also incorporates the effects of temperature and pressure on selected parameters. It was used to predict the performance of a full-scale unit operating at 650°C and 24 bara. The results indicate that a bed of Fuller's Earth pellets, 3-10 mm in diameter, 4 m long and 4 m wide can achieve exit alkali levels below 20 ppb wt in continuous operation for up to 24,000 hrs.
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36

Чудакевич, Володимир Ярославович. "Підвищення надійності роботи ТП 35/10 кВ із вибором методу регулювання напруги". Thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2017. http://elartu.tntu.edu.ua/handle/123456789/19113.

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У даній дипломній роботі проведено аналіз роботи трансформаторної підстанції 35/10 кВ для підвищення надійності її роботи шляхом модернізації основних складових частин системи електропостачання. Проведено розрахунок повної потужності споживачів, що живляться від підстанції, з врахуванням сезонності навантаження, та 10-ти річної перспективи розвитку енергоспоживання. Проведено обґрунтування необхідності заміни одного із трансформаторів підстанції на потужніший. Проведений розрахунок мережі енергоспоживання, розроблено захист силових трансформаторів, та вибрано необхідне комутаційне обладнання та іншу апаратуру. Запропоновано заходи для підвищення коефіцієнта потужності, для цього проведено розрахунки і запропоновано до встановлення конденсаторні установки, що дозволить компенсувати реактивну потужність. Проведено дослідження методів та засобів регулювання напруги на трансформаторній підстанції, що дозволить покращити показники якості електроенергії.
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37

Осінський, Віталій Вікторович. "Дослідження компенсації ємнісних струмів при роботі трансформаторної підстанції 35/10 кВ". Thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2017. http://elartu.tntu.edu.ua/handle/123456789/19281.

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У дипломній роботі проведено дослідження роботи трансформаторної підстанції 35/10 кВ, для визначення втрат електроенергії в електричній розподільчій мережі із розробкою заходів для підвищення якості електричної енергії. Визначено розрахункові навантаження споживачів електричної енергії. Проведено розрахунок втрат активної та реактивної потужності на всіх ділянках мережі, які отримують живлення від підстанції 35/10 кВ та в самій підстанції, а також визначення втрат електричної енергії в обладнанні підстанції. Проведено дослідження та розроблено заходи щодо підвищення ефективності засобів обмеження перенапруг і струмів при однофазних замиканнях на землю у мережі10 кВ. Проведено дослідження методів та способів компенсації ємнісних струмів в електричних мережах з заземленною нейтраллю через ступінчастий дугогасильний реактор.
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38

Польний, Тарас Вікторович. "Аналіз втрат електроенергії та розробка заходів по їх зниженню в електричних мережах РТП 35/10 кВ «Деражня»". Thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2017. http://elartu.tntu.edu.ua/handle/123456789/19088.

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Анотація:
У дипломній роботі проведено аналіз втрат електроенергії в електричних мережах трансформаторної підстанції 35/10 кВ та проведена реконструкція підстанції та електричних мереж 10 кВ для їх зниження й підвищення надійності системи електропостачання. Проведені розрахунки електричних навантажень на прогнозовану перспективу 10 років виходячи з існуючих навантажень на високовольтних лініях 10 кВ та коефіцієнту росту навантаження на розрахунковий період. Проведено обґрунтування заміни трансформаторів підстанції на більшу потужність. Запропонована спрощена формула розрахунку технічних втрат у колах 10 кВ за методом еквівалентного опору. Проведені розрахунки короткого замикання та здійснено вибір засобів автоматики захисту електричного обладнання для забезпечення надійності роботи. Проведена заміна повітряних проводів на ділянках 10 кВ системи електропостачання трансформаторної підстанції. Обґрунтовано та здійснено заміну масляних вимикачів на вакуумні типу ВU/TEL в ланках 10 кВ.
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39

Silue, Mamadou. "Numerical modelling of non-linear chemical reactions in power plant plumes." Thesis, Brunel University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299115.

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40

Ault, Graham W. "A planning and analysis framework for evaluating distributed generation and utility strategies." Thesis, University of Strathclyde, 2000. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21142.

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Анотація:
The numbers of smaller scale distributed power generation units connected to the distribution networks of electricity utilities in the UK and elsewhere have grown significantly in recent years. Numerous economic and political drivers have stimulated this growth and continue to provide the environment for future growth in distributed generation. The simple fact that distributed generation is independent from the distribution utility complicates planning and operational tasks for the distribution network. The uncertainty relating to the number, location and type of distributed generating units to connect to the distribution network in the future makes distribution planning a particularly difficult activity. This thesis concerns the problem of distribution network and business planning in the era of distributed generation. A distributed generation strategic analysis framework is proposed to provide the required analytical capability and planning and decision making framework to enable distribution utilities to deal effectively with the challenges and opportunities presented to them by distributed generation. The distributed generation strategic analysis framework is based on the best features of modem planning and decision making methodologies and facilitates scenario based analysis across many utility strategic options and uncertainties. Case studies are presented and assessed to clearly illustrate the potential benefits of such an approach to distributed generation planning in the UK electricity supply industry.
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41

Hawthorn, D. "The development of a theory to describe the deposition of calcium phosphate from recirculated cooling waters." Thesis, Nottingham Trent University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386270.

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42

Wakeley, Guy Richard. "The optimisation of steam turbine design." Thesis, University of Newcastle Upon Tyne, 1997. http://hdl.handle.net/10443/2041.

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Анотація:
The world market-place for steam turbine products is becoming increasingly competitive, and manufacturers must routinely produce designs which are extensively optimised whilst working within demanding tender and contract lead-times. The objective of the research work has been to develop a methodology whereby established turbomachinery analysis methods can be integrated within a framework of optimising algorithms. A rule-base, numerical optimisation, fuzzy logic, and genetic algorithms are used to optimise bladepath configurations, with particular emphasis on the minimisation of life-cycle operating costs. Significantly, automation of the design process is increased, design lead-times can be reduced, and performance improvements are predicted. The optimisation procedure relies on a sequential approach, with much emphasis placed on the iterative running of simple design codes. Simplified design methods are often reliant on correlated loss data to predict turbine performance, and in some cases this data is inaccurate or incomplete. An example of this is in the design of partially-admitted control stages, where little published data is available. It is suggested that CFD methods can, in some cases, be applied to derive new performance correlations or re-assess the validity of existing models. The application of an unsteady CFD solver to typical control stage geometries is presented in detail, and the approach is extended to include the development of a new control stage optimisation method.
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43

Brew-Hammond, John Peter Abeeku. "Technological accumulation and electric power generation in Sub-Saharan Africa : the case of Volta River Authority, Ghana." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363360.

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44

Watson, W. James. "Constructing success in the electric power industry : combined cycle gas turbines and fluidised beds." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246252.

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45

Prasad, Girijesh. "Performance monitoring and control for economical fossil power plant operation." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264537.

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46

Forsythe, Trevor David. "Adaptive control of a power station boiler." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359065.

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47

Rennie, Eleanor Jane. "Thermal performance of power station cooling towers." Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335762.

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48

Eastwick, Carol Norma. "Mathematical modelling of pulverised coal-fired burners." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283535.

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49

Hoggard, Martin. "Computer control of turbogenerators." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257189.

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50

Kiernan, Leo Andrew. "Learning systems for power transmission networks." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267908.

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