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Development of Deposition and Characterization Systems for Thin Film Solar CellsCimaroli, Alexander J. January 2016 (has links)
No description available.
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DFIG-BASED SPLIT-SHAFT WIND ENERGY CONVERSION SYSTEMSRasoul Akbari (13157394) 27 July 2022 (has links)
<p>In this research, a Split-Shaft Wind Energy Conversion System (SS-WECS) is investigated</p>
<p>to improve the performance and cost of the system and reduce the wind power</p>
<p>uncertainty influences on the power grid. This system utilizes a lightweight Hydraulic Transmission</p>
<p>System (HTS) instead of the traditional gearbox and uses a Doubly-Fed Induction</p>
<p>Generator (DFIG) instead of a synchronous generator. This type of wind turbine provides</p>
<p>several benefits, including decoupling the shaft speed controls at the turbine and the generator.</p>
<p>Hence, maintaining the generator’s frequency and seeking maximum power point</p>
<p>can be accomplished independently. The frequency control relies on the mechanical torque</p>
<p>adjustment on the hydraulic motor that is coupled with the generator. This research provides</p>
<p>modeling of an SS-WECS to show its dependence on mechanical torque and a control</p>
<p>technique to realize the mechanical torque adjustments utilizing a Doubly-Fed Induction</p>
<p>Generator (DFIG). To this end, a vector control technique is employed, and the generator</p>
<p>electrical torque is controlled to adjust the frequency while the wind turbine dynamics</p>
<p>influence the system operation. The results demonstrate that the generator’s frequency is</p>
<p>maintained under any wind speed experienced at the turbine.</p>
<p>Next, to reduce the size of power converters required for controlling DFIG, this research</p>
<p>introduces a control technique that allows achieving MPPT in a narrow window of generator</p>
<p>speed in an SS-WECS. Consequently, the size of the power converters is reduced</p>
<p>significantly. The proposed configuration is investigated by analytical calculations and simulations</p>
<p>to demonstrate the reduced size of the converter and dynamic performance of the</p>
<p>power generation. Furthermore, a new configuration is proposed to eliminate the Grid-</p>
<p>Side Converter (GSC). This configuration employs only a reduced-size Rotor-Side Converter</p>
<p>(RSC) in tandem with a supercapacitor. This is accomplished by employing the hydraulic</p>
<p>transmission system (HTS) as a continuously variable and shaft decoupling transmission</p>
<p>unit. In this configuration, the speed of the DFIG is controlled by the RSC to regulate the</p>
<p>supercapacitor voltage without GSC. The proposed system is investigated and simulated in</p>
<p>MATLAB Simulink at various wind speeds to validate the results.</p>
<p>Next, to reduce the wind power uncertainty, this research introduces an SS-WECS where the system’s inertia is adjusted to store the energy. Accordingly, a flywheel is mechanically</p>
<p>coupled with the rotor of the DFIG. Employing the HTS in such a configuration allows the</p>
<p>turbine controller to track the point of maximum power (MPPT) while the generator controller</p>
<p>can adjust the generator speed. As a result, the flywheel, which is directly connected</p>
<p>to the shaft of the generator, can be charged and discharged by controlling the generator</p>
<p>speed. In this process, the flywheel energy can be used to modify the electric power generation</p>
<p>of the generator on-demand. This improves the quality of injected power to the</p>
<p>grid. Furthermore, the structure of the flywheel energy storage is simplified by removing</p>
<p>its dedicated motor/generator and the power electronics driver. Two separate supervisory</p>
<p>controllers are developed using fuzzy logic regulators to generate a real-time output power</p>
<p>reference. Furthermore, small-signal models are developed to analyze and improve the MPPT</p>
<p>controller. Extensive simulation results demonstrate the feasibility of such a system and its</p>
<p>improved quality of power generation.</p>
<p>Next, an integrated Hybrid Energy Storage System (HESS) is developed to support the</p>
<p>new DFIG excitation system in the SS-WECS. The goal is to improve the power quality</p>
<p>while significantly reducing the generator excitation power rating and component counts.</p>
<p>Therefore, the rotor excitation circuit is modified to add the storage to its DC link directly.</p>
<p>In this configuration, the output power fluctuation is attenuated solely by utilizing the RSC,</p>
<p>making it self-sufficient from the grid connection. The storage characteristics are identified</p>
<p>based on several system design parameters, including the system inertia, inverter capacity,</p>
<p>and energy storage capacity. The obtained power generation characteristics suggest an energy</p>
<p>storage system as a mix of fast-acting types and a high energy capacity with moderate</p>
<p>acting time. Then, a feedback controller is designed to maintain the charge in the storage</p>
<p>within the required limits. Additionally, an adaptive model-predictive controller is developed</p>
<p>to reduce power generation fluctuations. The proposed system is investigated and simulated</p>
<p>in MATLAB Simulink at various wind speeds to validate the results and demonstrate the</p>
<p>system’s dynamic performance. It is shown that the system’s inertia is critical to damping</p>
<p>the high-frequency oscillations of the wind power fluctuations. Then, an optimization approach</p>
<p>using the Response Surface Method (RSM) is conducted to minimize the annualized</p>
<p>cost of the Hybrid Energy Storage System (HESS); consisting of a flywheel, supercapacitor, and battery. The goal is to smooth out the output power fluctuations by the optimal</p>
<p>size of the HESS. Thus, a 1.5 MW hydraulic wind turbine is simulated, and the HESS is</p>
<p>configured and optimized. The direct connection of the flywheel allows reaching a suitable</p>
<p>level of smoothness at a reasonable cost. The proposed configuration is compared with the</p>
<p>conventional storage, and the results demonstrate that the proposed integrated HESS can</p>
<p>decrease the annualized storage cost by 71 %.</p>
<p>Finally, this research investigates the effects of the reduced-size RSC on the Low Voltage</p>
<p>Ride Through (LVRT) capabilities required from all wind turbines. One of the significant</p>
<p>achievements of an SS-WECS is the reduced size excitation circuit. The grid side converter is</p>
<p>eliminated, and the size of the rotor side converter (RSC) can be safely reduced to a fraction</p>
<p>of a full-size excitation. Therefore, this low-power-rated converter operates at low voltage</p>
<p>and handles the regular operation well. However, the fault conditions may expose conditions</p>
<p>on the converter and push it to its limits. Therefore, four different protection circuits are</p>
<p>employed, and their effects are investigated and compared to evaluate their performance.</p>
<p>These four protection circuits include the active crowbar, active crowbar along a resistorinductor</p>
<p>circuit (C-RL), series dynamic resistor (SDR), and new-bridge fault current limiter</p>
<p>(NBFCL). The wind turbine controllers are also adapted to reduce the impact of the fault</p>
<p>on the power electronic converters. One of the effective methods is to store the excess energy</p>
<p>in the generator’s rotor. Finally, the proposed LVRT strategies are simulated in MATLAB</p>
<p>Simulink to validate the results and demonstrate their effectiveness and functionality.</p>
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The Development of a DC Micro-grid model with Maximum Power Point Tracking for Waste Heat Recovery SystemsElrakaybi, Ahmed 06 1900 (has links)
Research in sustainable energy sources has become the interest of many studies due to the increasing energy demand and the amount of wasted energy released from existing methods, along with their effect on climate change and environment sustainability. Thermo-Electric Generators (TEGs) are a potential solution that is being studied and implemented as they can convert low grade thermal energy to useful electrical energy at various operating conditions.
The integration of a TEG within a heat exchanger (TEG/HX) system connected to an electrical DC micro-grid, using a Maximum Power Point Tracking (MPPT) system is the focus of this study. Using a numerical TEG/HX model from a previous study and a developed DC micro-grid model the interaction between the thermal and electrical aspects were investigated with the focus on the electrical performance of the system.
The main concern of this study is to investigate the effect of the sub components of the DC micro-grid on the overall available energy. An analytic model was developed to estimate the power loss in the electrical circuit of the micro-grid, the model utilizes the equations for switching and conduction losses which have been used by several studies. Other variables such as the battery characteristics and electrical load profiles were also investigated by simulating several case studies including changing operating conditions.
This study shows the effect of a TEG configuration on the power loss in an electrical system using power loss curves in comparison with the Open Circuit Voltage (OCV) of such configuration. It also covers important modes of operation for the battery, loads and MPPT for a stable and reliable operation of an isolated DC micro-grid system were TEGs are the only source of power.
The result of the study presented is a system design that is able to maximize the electrical energy harvested from the TEGs to extend the operation of the dc-micro-grid first by applying a suitable TEG configuration and consequently a suitable electrical circuit. Secondly, by adapting to the changing operating conditions of the TEGs and the loads; and compensating for these changes using the battery storage system. / Thesis / Master of Applied Science (MASc)
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Multi-source Energy Harvesting for Wildlife TrackingWu, You 06 July 2015 (has links)
Sufficient power supply to run GPS machinery and transmit data on a long-term basis remains to be the key challenge for wildlife tracking technology. Traditional ways of replacing battery periodically is not only time and money consuming but also dangerous to live-trapping wild animals. In this paper, an innovative wildlife tracking collar with multi-source energy harvester with advantage of high efficiency and reliability is proposed. This multi-source energy harvester entails a solar energy harvester and an innovative rotational electromagnetic energy harvester is mounted on the "wildlife tracking collar" which will extend the duration of wild life tracking by 20% time as was estimated. A feedforward and feedback control of DC-DC converter circuit is adopted to passively realize the Maximum Power Point Tracking (MPPT) logic for the solar energy harvester. A novel electromagnetic pendulum energy harvester with motion regulator is proposed which can mechanically rectify the irregular bidirectional swing motion of the pendulum into unidirectional rotational motion of the motor. No electrical rectifier is needed and voltage drops from diodes can be avoided, the EM pendulum energy harvester can provide 200~300 mW under the 0.4g base excitation of 4.5 Hz. The nonlinearity of the disengage mechanism in the pendulum energy harvester will lead to a broad bandwidth frequency response. Simulation results shows the broadband advantage of the proposed energy harvester and experiment results verified that at some frequencies over the natural frequency the efficiency is increased. / Master of Science
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Implementering av MPPT-enhet med återkoppling : avsedd för solcellerBergroth, Simon January 2019 (has links)
No description available.
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Otimização meta heurística e controle baseado no modelo interno aplicados em sistemas de geração fotovoltaica conectados à rede elétrica monofásicaChaves, Eric Nery 18 November 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho apresenta o estudo, desenvolvimento e aplicação de novas técnicas de controle aos
sistemas de geração de energia fotovoltaica, conectados à rede elétrica monofásica, visando a
melhoria da eficiência destes sistemas em relação aos métodos de controle tipicamente utilizados. O
trabalho é dividido em duas partes principais, as quais estão relacionadas ao rastreamento do ponto
de máxima potência (Maximum Power Point Tracking – MPPT) e, depois, ao controlador interno
dos conversores boost-quadrático – lado dos painéis fotovoltaicos – assim como aos controladores
do inversor de tensão, no lado da rede elétrica monofásica. A primeira parte do trabalho consiste no
desenvolvimento de um algoritmo de meta heurística para o MPPT, o qual é baseado no método do
recozimento simulado (Simulated Annealing - SA) e tem como objetivo a determinação do ponto de
máximo global, buscando soluções fora de uma vizinhança próxima, de modo a evitar o
atracamento em máximos locais da curva de potência de saída do arranjo de painéis fotovoltaicos,
melhorando, assim, o aproveitamento da energia em situações de sombreamento parcial. A segunda
parte do trabalho apresenta o projeto de controladores baseados no modelo interno (Internal Model
Control – IMC) com 1 grau de liberdade (1 Degree of Freedom – 1 DOF) aplicados, primeiramente,
ao conversor CC-CC Boost Quadrático, utilizado para o MPPT, e, posteriormente, a um inversor de
tensão com filtro LCL, conectado à rede elétrica monofásica, operando no modo de injeção de
corrente. É apresentada a modelagem matemática de ambos os conversores e analisada a
compensação da realimentação interna ao sistema do inversor de tensão, correspondente ao
desacoplamento da tensão da rede, através da estratégia de alimentação à frente (Feedforward).
Visando-se uma base de comparação, para a análise de desempenho do conversor IMC – 1DOF,
também é aplicado ao sistema de injeção de corrente, o controlador Proporcional-Ressonante
(P+Res). São apresentados resultados de simulação computacional e experimentais de ambos os
8
controladores, os quais permitem verificar o desempenho do sistema em situação de rede fraca e
carga local não-linear. / This paper presents the study, development and application of new control techniques for
photovoltaic power generation systems, connected to single-phase power grid in order to improve
the efficiency of these systems in relation to control methods typically used. The work is divided
into two main parts, which are related to tracking the maximum power point (Maximum Power
Point Tracking - MPPT) and then the internal controller of boost quadratic converters - side of the
photovoltaic panels - as well as the controllers the voltage inverter, the side of the single-phase
mains. The first part of the work is the development of a heuristic goal algorithm for MPPT, which
is based on the method of simulated annealing (Simulated Annealing - SA) and aims at determining
the overall maximum point, seeking out solutions in a close vicinity, so as to prevent the docking
local maxima in the curve of power output of the photovoltaic array, thereby improving the
utilization of energy in partial shading situations. The second part presents the design of controllers
based on internal model (Internal Model Control - IMC) with 1 degree of freedom (1 Degree of
Freedom - 1 DOF) applied, first, the DC-DC Boost Quadratic converter, used for MPPT, and
thereafter, a voltage inverter with LCL filter connected to the single phase power supply operating
in current injection mode. A mathematical modeling of both converters and analyzed the
compensation of internal feedback to the voltage inverter system corresponding to the disconnection
of the mains voltage through the power strategy a head (feedforward). A basis of comparison for the
performance analysis of IMC-1DOF converter is aiming at, is also applied to the current injection
system, Proportional-Resonant Controller (P + Res). They are presented computer simulation and
experimental results of both controllers, which allow you to check the system performance in low
and non-linear local load network situation. / Tese (Doutorado)
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Dimensionamento e gestão de energia solar fotovoltaica para aplicação em sistemas automatizados isolados da rede elétricaBorges, Leandro da Motta 27 September 2013 (has links)
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Previous issue date: 2013-09-27 / Este trabalho apresenta o estudo, dimensionamento e gestão de um sistema solar fotovoltaico isolado da rede elétrica para alimentar cargas de equipamentos de automação industrial. Um exemplo de aplicação são unidades de comando e sinalização ferroviária que, em alguns casos, são comandadas por relés e, mais atualmente, sendo substituídas por Controladores Lógico Programáveis. No sistema solar fotovoltaico isolado, o excedente de energia elétrica produzida nos painéis solares fotovoltaicos é armazenado em baterias eletroquímicas estacionárias de chumbo-ácido para posterior aproveitamento durante o período noturno e de baixa produção de eletricidade. Esse tipo de bateria apresenta efeito de memória, não pode sofrer descarga profunda ou ser submetida a tensões elevadas. Assim, este trabalho visa especificar e dimensionar um sistema solar fotovoltaico para aplicações em cargas de automação industrial isolados da rede elétrica, bem como assegurar elevada vida útil da bateria eletroquímica de chumbo-ácido sem prejudicar o rastreamento de máxima potência dos painéis solares fotovoltaicos. Para isso, uma estratégia de gestão de energia possibilita alterar o controle do conversor CC-CC que realiza a interconexão entre os painéis solares fotovoltaicos e a bateria eletroquímica. Resultados de simulação computacional apontam para o bom desempenho conceitual do sistema e seu potencial para a aplicação pretendida. / This work presents the study, design and management of a stand-alone photovoltaic system to feed industrial automation load. E examples of application are railway signaling unit controls, which in some cases are controlled by electromechanical relays and more currently being replaced by programmable logical controllers. In a stand-alone photovoltaic system, the excess of electricity produced in the photovoltaic panels is stored in lead-acid stationary electrochemical batteries for later use during the night and low electricity production periods. This kind of battery presents memory effect, cannot have deep discharge or be subjected to high voltages. Thus, this work aims to specify and size a solar photovoltaic system for applications in industrial automation loads isolated from the grid, as well as ensuring longer lifetime to electrochemical battery of lead-acid without harming the maximum power tracker of photovoltaic panels. For this, a strategy for changing power management enables the control of DC-DC converter that performs the interconnection of photovoltaic panels and electrochemical battery. Results of computer simulation indicate the good conceptual performance of the system and its potential for the intended application.
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The Challenge of Designing Gestures for InteractionEriksson, Anette, Svensson, Caroline January 2001 (has links)
The main interfaces for interaction with computers today are; keyboard, mouse and remote control. In order to interact with the presentation software Power Point, the presenter has to focus either on the computer or the buttons on the remote control. By doing this, the presenter often loses the contact with his audience and his or her flow of speech gets interrupted. This project has researched the possibility of using gestures for interaction with Power Point, by using an appliance that detects gestures. The purpose was that the interaction should be possible to realise by software, which we have done an introductory design of. We have focused on assisting presenters when they use Power Point and other applications when delivering presentation. To collect data and get an understanding of presenters, presentations and gestures we have observed presenters in action, done workshops together with future users and tested some gestures in real life. These are methods inspired from approaches such as ethnographic fieldwork and participatory design. During the whole project we have used video recording to collect and save data. To create an understanding and clear picture of what the future software should include UML-diagrams were used. We have separated gestures in two categories; natural and designed. The natural gestures occur naturally during speech and social interaction, while the designed gestures are gestures that you learn to use and express, often to perform a task. We discovered that it was the designed gestures that are best suited for gestural interaction with computer. Since the designed gestures are close to the natural way of gesturing we see them as easier to learn, remember and also more comfortable to use. We think the designed gestures have the potential to become second nature, therefore they are good to use for interaction with computers. Our research work led us to realise a need for an on/off function, to distinguish the designed gestures from the natural ones. By using a gestural interface during a presentation, the presenters can keep the focus on the audience and the message they want to convey. When gestural interfaces become reality they will introduce a paradigm shift in the way that people interact with computers and information. / Anette Eriksson 0457-12196 Caroline Svensson 0410-24148
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Systém napájení domácnosti z obnovitelných zdrojů energie / Power Supply System for Housis Using Renewable ResourcesGálus, Matej January 2011 (has links)
The aim of this thesis is to describe the advantages of simultaneous utilization of photovoltaic and wind electricity in an autonomous system, supplying the household with electricity without connection to the electrical grid. The most used methods of connecting photovoltaic modules and wind generators to chemical batteries are discussed. Several maximum power point tracking methods and their properties are described. A block schematic diagram of an autonomous off-grid system utilizing chemical accumulators is proposed. The system also contains an inverter producing standard mains voltage 230 VAC to supply common household appliances. A Quasi-Square Wave converter topology was chosen for all three power converters. An experimental 180 W output power QSW converter with one controllable switch was designed, simulated with Pspice, manufactured and tested to verify the efficiency of the topology. Excellent agreement was found between predicted and measured efficiency at full output power. Efficiency for reliable operation varies between 89% and 92,2% at full power and depends mainly power inductor and MOSFET used. After successful evaluation of QSW topology, the power converters for the main system were designed. Because of higher power, the converters were designed as four-phase, whereas each phase contains two controllable switches to boost efficiency mainly in low-power area. The most critical and difficult part of the project was to design the mixed-signal control sections for the converters to ensure proper switching of two controllable MOSFETs in each phase. For user interactivity, main control board with graphic LC display, Ethernet module and SD memory card slot was also manufactured.
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Měřicí systém pro sledování efektivity fotovoltaického panelu / Measuring system of photovoltaic modules efficiencyVrána, Michal January 2012 (has links)
This thesis describes the design of the active load for adjusting the maximum power point of PV module and the module loaded with the defined parameters for measuring the effectiveness and identifying the characteristics of the PV module.
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