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Modélisation des panneaux photovoltaïques et adaptation de la cyclostationnarité pour le diagnostic / Modelisation of photovolatic panels and an adaptation of cyclostationarity to diagnosticTelidjane, Mohammed 13 July 2017 (has links)
Les systèmes photovoltaïques (PV) peuvent être exploités dans différents lieux. L'exposition extérieure des panneaux PV mets en jeu une combinaison complexe de facteurs (le vent, la pluie, la neige, la chaleur, la foudre, ombrage, …) qui provoquent leurs dégradations au cours du temps et réduit leurs rendement. Le diagnostic est parmi les solutions intéressantes en vue de faire fonctionner des panneaux PV à leur puissance optimale et afin de maximiser l'efficacité de la conversion PV dans le but de réduire les coûts de maintenance. Dans ce travail de thèse, nous nous intéressons uniquement au diagnostic des générateurs PV. L'objectif de cette thèse est de proposer des outils de traitement de signal permettant de détecter et de localiser des défauts conduisant à une baisse de rendement. Pour mener ce travail, nous faisons tout d'abord un état de l'art sur les panneaux photovoltaïques de l'aspect microscopique (cellule) à l'aspect macroscopique (champs). Pour commencer, nous présentons le principe de fonctionnement d'une cellule photovoltaïque. Parallèlement à cela, nous décrivons les différents types de défauts et présentons un panorama des méthodes de leur détection. La seconde partie, consacrée aux outils théoriques. On rappelle la définition de la cyclostationnarité et des outils associés à la cyclostationnarité à l'ordre 1 (moyenne synchrone) et l'ordre 2 (corrélation spectrale). Les performances des panneaux PV dépendant principalement des conditions météorologiques (irradiance, température), ces conditions présentent des propriétés cyclostationnaires (CS) et permettent de décomposer les signaux en un motif cyclique (CSI) et un motif aléatoire cyclostationnaire à l'ordre 2 (CS2). La CS2 est associée à des phénomènes météorologiques comme les passages nuageux. À l'aide d'exemples, nous montrons que les outils classiques (Moyenne Synchrone,Cepstre) utilisés dans le domaine de la CS ne permettent pas une bonne séparation de la composante cyclique et la partie aléatoire pour le signal d'ensoleillement à cause de la variation d'amplitude d'un cycle à un autre engendré par l'effet de la saisonnalité. C'est pourquoi nous introduisons dans ce travail une méthode originale appelée ATSA adapté à ce type de signaux. Une troisième partie traitant de la modélisation de défauts indique comment construire une base de données de signaux électriques par simulation. De nombreux modèles électriques sont utilisés dans la littérature pour comprendre le fonctionnement des panneaux PV. Le modèle de Bishop a été retenu dans cette étude, car il représente bien la caractéristique courant tension (1-V) du fonctionnement des cellules PV dans régime direct ainsi que dans le régime inverse dans le cas où une cellule est occultée. Les signaux électriques des indicateurs (puissance maximale, courant court circuit et tension circuit ouvert) sont ensuite calculés à partir de la caractéristique I-V du panneau PV obtenue pour des conditions spécifiques (irradiance, température, défaut de mismatch, défaut de diode de bypass) L'originalité de notre travail est de simuler les signaux en utilisant des caractéristiques d'ensoleillement réelles obtenu par mesure satellite. Nous introduisons ainsi la notion de saisonnalité dans la caractéristique I-V qui dépend alors du temps. La fonction d'autocorrélation cyclique est appliquée sur les parties aléatoires des signaux afin de travailler sur la CS à l'ordre2 (CS2). Dans la quatrième partie, on montre comment combiner les outils tels que l'ATSA pour faire du diagnostic sur les signaux que nous avons simulés. Dans cette étude, la CS2 des signaux a donné de bons résultats pour faire du diagnostic en comparant par l'analyse temporelle et fréquentielle / Photovoltaic (PV) systems can be operated in different locations. The exhibition (Wind, rain, snow, heat, lightning, shading, etc.) which cause their degradation over time and reduc their efficiency. Diagnosis is one of the interesting solutions to make PV panels work at their optimum power and in order to maximize the efficiency of PV conversion in order to reduce maintenance costs. In this thesis work, we are interested only in the diagnosis of PV generators. The aim of this thesis is to propose signal processing tools to detect and locate faults leading to a drop in efficiency. To carry out this work, we first make a stateof the art on the panels. Photovoltaic cells of microscopic appearance (cell) with macroscopic appearance (fields). To begin, we present the principle of operation of a photovoltaic cell as well as the various parameters affecting its performance. The combination of cells to create a photovoltaic panel, panels to create fields, are the studied. It is then shown how to connect these elements to a Load and network. At the same time, we describe the different types of defects and present an overview of the methods of their detection. A third part dealing with the modeling of defects shows how to build a database of electrical signals by simulation. Many electrical models are used in the literature to understand the functioning of PV panels. The Bishop model has been chosen in this study because it represents the current voltage characteristic (I-V) of the functioning of the PV cells in direct regime as well as in the inverse regime in the case where a cell is occulted. We explain how the different types of defects affect the I-V characteristic of solar panels. The electrical signals of the indicators (maximum power, short circuit current and open circuit voltage) are then calculated from the characteristic [V of the PV panel obtained for specific conditions (irradiance, temperature, mismatch defect, bypass diode fault). .). The originality of our work is to simulate the signals using real sunlight characteristics obtained by satellite measurements. We introduce the notion of seasonality into the characteristic I-V which then depends on time. We then analyze the first signals obtained by simulation. The time evolution of these indicators shows a CS aspect and the ATSA method is applied for these signals to have a good separation of the cyclic pattern and the random pattern of the time signals. The separation of these two components. To work on different CS commands. The cyclic autocorrelation function is applied to the random parts of the signals to work on the CS to order2 (CS2). In the fourth part, we show how to combine tools such as ATSA to diagnose the signals we simulated. We first present our choice of types of defects and severity used to build our database. Next, we describe and illustrate the various indicator in detail for a shading defect. A larger study is then carried out on all the simulated defects. In this study, the CS2 of the signals gave good results to make the diagnosis by comparing by the time and frequency analysis
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Μελέτη συμπεριφοράς φωτοβολταϊκών πλαισίων σε καταπόνηση με κρουστικές τάσεις κεραυνώνΝταλάκας, Χρήστος 30 April 2014 (has links)
Η παρούσα διπλωματική εργασία καταπιάνεται με τη μελέτη της συμπεριφοράς των φωτοβολταϊκών πλαισίων σε καταπόνηση με κρουστικές τάσεις κεραυνών. Πιο συγκεκριμένα, εφαρμόστηκαν σε ένα φωτοβολταϊκό πλαίσιο κρουστικές τάσεις, συμφωνά με τον κανονισμό IEC 61730-2,και μετρήθηκε το αν και κατά πόσο επηρεάστηκε η λειτουργία του πλαισίου.
Το πρώτο κεφάλαιο παρέχει το θεωρητικό πλαίσιο της έρευνας. Αναλυτικότερα, παρέχεται η αρχή λειτουργίας του μονοκρυσταλλικού πλαισίου, και αναφέρονται τα τεχνικά χαρακτηριστικά αυτού που χρησιμοποιήσαμε στην παρούσα εργασία. Παρατίθεται η αρχή λειτουργίας της κρουστικής γεννήτριας που χρησιμοποιήθηκε στο πειραματικό σκέλος και δίνεται ο ορισμός της κρουστικής τάσης. Τέλος, δίνονται πληροφορίες ως προς τη μετρητική συσκευή που χρησιμοποιήθηκε για τη μελέτη της καλής λειτουργίας του πλαισίου.
Το δεύτερο κεφάλαιο σχετίζεται με το πειραματικό κομμάτι της έρευνας. Πιο συγκεκριμένα, παρατίθενται οι κρουστικές τάσεις που έπληξαν το πλαίσιο και γίνεται εκτενής και σαφής αναφορά στον κανονισμό IEC 61730-2 που υπαγορεύει τους κανόνες διεξαγωγής του πειράματος. Τέλος, παρουσιάζονται οι ακριβείς συνθήκες διεξαγωγής της πειραματικής διαδικασίας ενώ περιέχονται φωτογραφίες που πάρθηκαν κατά τη διάρκεια υλοποίησης της έρευνας.
Στο τρίτο κεφάλαιο καταγράφονται τα αποτελέσματα των μετρήσεων καλής λειτουργίας του φωτοβολταϊκού πλαισίου και παρουσιάζονται σε πίνακες και χαρακτηριστικές I-V. Αποτελέσματα που πάρθηκαν τόσο πριν όσο και μετά από κάθε καταπόνηση.
Κλείνοντας, στο τέταρτο και τελευταίο κεφαλαίο, εξάγονται συμπεράσματα και γίνεται εκτενής ανάλυση των αποτελεσμάτων που καταγράφηκαν στο κεφάλαιο 3. Τα τελικά συμπεράσματα σχετίζονται με το αν επηρεάστηκε ή όχι η καλή λειτουργία του κυττάρου. Ακόμα, παρουσιάζονται κάποιες αδυναμίες της έρευνας μας καθώς και κάποια ερωτήματα-προτάσεις περεταίρω διευρένησης, που μας γεννήθηκαν κατά την ενασχόλησή μας με το θέμα. / This thesis deals with the study of the behavior of the modules when applying lightning impulse voltages. In particular, percussive tendencies were applied to a solar cell, according to the regulation IEC 61730-2, and it was measured whether and how the functioning of the framework was affected.
The first chapter provides the theoretical framework of the research. More specific, it is given the operating principle of the single crystal framework and there are referred the technical features which were used in this work. It is presented the operating principle of the impulse generator used in the experimental arm and it is given the definition of “voltage impulse”. Finally, there are presented information on the measuring device used to the study of the proper functioning of the framework.
The second chapter is related to the experimental part of the investigation. To be more specified, there are given the percussive tendencies that affected cell and a detailed and clear reference to IEC 61730-2 regulation that dictates the rules of our experiments. Finally, we present the precise conditions under which the experimental procedure was done and there are contained photographs which were took during the implementation of the survey.
In the third chapter, they are displayed the results of the measurements proper operation of photovoltaic panel and they are presented in tables and characteristic IV. The results were obtained both before and after each exposure
Finally, in the fourth and final chapter, conclusions are drawn and there is a detailed analysis of the results recorded in chapter 3. The final conclusions relating to whether or not the proper cell function was affected . In conclusion, they are presented some shortcomings in our research and some questions (further recommendations for research), there were entered to our minds during our involvement with the issue.
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Aspectos regulatorios a considerar en la implementación de la micro generación distribuida residencial fotovoltaica en el mercado eléctrico peruano / Regulatory aspects to consider in the implementation of photovoltaic residential distributed micro generation in the Peruvian electricity marketPalacios Esteban, David Yuri, Rojas Ramírez, Ruben, Ramirez Soto, Edwin 11 1900 (has links)
El presente trabajo ha sido elaborado con la finalidad de proponer lineamientos de aspectos regulatorios de la Micro Generación Distribuida Residencial Fotovoltaica (MGDRF), para que los usuarios regulados residenciales que consumen energía eléctrica de la red, tengan la facultad de producir energía eléctrica para su autoconsumo, obteniendo un reconocimiento económico por sus excedentes que se inyectan a la red eléctrica. Cabe precisar que los usuarios residenciales, no tienen capacidad de negociación con sus suministradores (distribuidores) para reducir sus facturaciones por energía eléctrica.
La implementación de la MGDRF, brinda la oportunidad de generar energía eléctrica libre de contaminación sonora y ambiental, siendo necesario su regulación a fin de que se defina principalmente la potencia máxima a generar, requisitos y criterios técnicos que se deben cumplir, así como establecer el mecanismo comercial por la energía inyectada a la red, cuando la generación sea mayor a la energía autoconsumida. Mediante el trabajo desarrollado se han evaluado aspectos regulatorios de diversos países, asimismo, se han efectuado evaluaciones económicas para elegir el mecanismo comercial que genere mayores incentivos para que los usuarios tomen la decisión de realizar la inversión de la MGDRF.
Para lograr el desarrollo de la Generación Distribuida en el menor plazo posible, como viene sucediendo en otros países, es necesario que no se continúe postergando la aprobación del Reglamento de Generación Distribuida. Para ello, consideramos que debe promoverse la MGDRF por ser una energía limpia, accesible y con bajo impacto técnico económico en la operatividad de la empresa de distribución. / The present work has been prepared with the purpose of proposing guidelines of regulatory aspects of the Photovoltaic Residential Distributed Micro Generation (PRDMG), so that residential regulated users who consume electricity from the network, have the power to produce electricity for their own consumption, obtaining economic recognition for its surpluses that are injected into the electricity grid. It should be noted that residential users do not have the ability to negotiate with their suppliers (distributors) to reduce their electricity bills.
The implementation of the PRDMG, provides the opportunity to generate electrical energy free of noise and environmental pollution, its regulation being necessary in order to define mainly the maximum power to be generated, requirements and technical criteria that must be met, as well as establish the commercial mechanism for the energy injected into the network, when the generation is greater than the self-consumed energy. Through the work carried out, regulatory aspects of various countries have been evaluated, as well as economic evaluations to choose the commercial mechanism that generates the greatest incentives for users to make the decision to make the PRDMG investment.
To achieve the development of Distributed Generation in the shortest possible time, as is happening in other countries, it is necessary that the approval of the Distributed Generation Regulation is not postponed. To this end, we believe that PRDMG should be promoted as a clean energy, accessible with low economic technical impact on the operation of the distribution company. / Trabajo de Investigación
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Aplicação de algoritmos de busca do ponto de máxima potência e controladores lineares e/ou fuzzy para a regulação da tensão terminal de painéis fotovoltaicos / Application of maximum power point tracking algorithms and linear and/or nonlinear fuzzy logic control to regulate the voltage of photovoltaic panelsMoçambique, Nilton Eufrázio Martinho 06 June 2012 (has links)
Algoritmos de busca do ponto de máxima potência (MPPT) são largamente utilizados para se obter a potência máxima fornecida em sistemas fotovoltaicos. Apesar de existirem diversas técnicas de MPPT, os métodos heurísticos de busca como o método da perturbação e observação (P&O) e o método da Condutância Incremental (InC) são os mais usuais por serem simples e confiáveis. Assim, é proposto uma lei de controle com realimentação da tensão de saída de um painel fotovoltaico (PV) de forma a manter o mesmo operando próximo ao ponto de máxima potência, possibilitando com isso uma melhora do desempenho do algoritmo de P&O e InC inclusive quando o painel PV é submetido a rápidas mudanças na irradiação solar. Além disso, devido às características não lineares dos painéis fotovoltaicos, a utilização de técnicas inteligentes que empregam controladores fuzzy para o controle da tensão terminal do PV, parece ser uma solução viável quando comparada aos controladores clássicos com PI e PID, principalmente, porque tais estruturas de controle proporcionam uma lenta resposta dinâmica e problemas de estabilidade relacionados às oscilações em torno do ponto de máxima potência, decorrente do funcionamento dos algoritmos P&O e InC. / Maximum power point tracking (MPPT) techniques are widely used to achieve the maximum output power of a photovoltaic (PV) system. Although there are many MPPT techniques, the heuristic search methods such as perturb and observe (P&O) and incremental conductance (InC) method are the most commonly used because they are simple and reliable in the pursuit of maximum power point. A control law with feedback of the output voltage of a photovoltaic (PV) panel is proposed, in order to maintain it working nearby the maximum power point, enabling an improvement in the performance of the algorithm for P&O and InC even when the PV array is subjected to rapid changes in solar irradiance. Moreover, due to the nonlinear characteristics of the photovoltaic panels, the technique that employ fuzzy logic control seems to be a viable option when compared with conventional proportional and integral or proportional, integral and derivative controllers, mainly because such control structures provide a slow dynamic response and stability issues related to oscillations around the maximum power point due to operation of P&O and InC algorithms.
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Sistema fotovoltaico para comunidades isoladas utilizando ultracapacitores para armazenamento de energia / Photovoltaic system for isolated communities using ultracapacitors for energy storageJosà Mascena Dantas 21 December 2012 (has links)
Universidade Federal do Cearà / Este trabalho apresenta a concepÃÃo, projeto e implementaÃÃo de um conversor CC/CC
elevador para interligar um painel fotovoltaico a um banco de ultracapacitores para
armazenamento de energia em substituiÃÃo Ãs baterias automotivas convencionais. Na saÃda
dos ultracapacitores utiliza-se um conversor CC/CC abaixador, que fornece essa energia a um
sistema de telecomunicaÃÃo para suprimento de um transceptor monocanal visando ao
atendimento do serviÃo de telefonia rural/Internet em comunidades isoladas da rede pÃblica
de energia. O sistema pode suprir o serviÃo de comunicaÃÃo para uma comunidade isolada da
rede de energia elÃtrica por atà trÃs horas no perÃodo noturno, quando utilizado um
equipamento rÃdio com cabos, conectores e antena para transmissÃo e recepÃÃo de sinal de
telefonia com potÃncia de consumo de 13 W e com radiaÃÃo solar mÃdia de 5.500 W/m2/dia.
Durante o dia, a energia solar à capturada por um painel fotovoltaico e armazenada em
ultracapacitores atravÃs de um conversor boost. Este conversor possibilita a carga dos
ultracapacitores no ponto de mÃxima potÃncia (MPP) do painel fotovoltaico. O transceptor Ã
ativado quando se tira o fone do gancho e a alimentaÃÃo do sistema vem do painel via
ultracapacitores. Caso haja ligaÃÃes durante o dia, o painel fotovoltaico supre as necessidades
do equipamento transceptor. Ã noite, o painel utilizado nÃo gera energia suficiente para
alimentar o sistema de telecomunicaÃÃo. No perÃodo noturno, caso ocorra uma chamada
telefÃnica para o sistema proposto, o transceptor serà acionado, o assinante deverà retirar o
monofone do gancho do aparelho telefÃnico para realizar o atendimento. Durante essa
operaÃÃo o transceptor consome aproximadamente 13 W de potÃncia, que à fornecida pelos
ultracapacitores, os quais estÃo interligados atravÃs do conversor buck. O sistema proposto Ã
controlado por um microcontrolador e um circuito de controle, que procura o ponto de
mÃxima potÃncia (MPP) do painel fotovoltaico, monitora o nÃvel da tensÃo dos
ultracapacitores e determina o tempo de funcionamento do conversor CC/CC, que possibilita
o fornecimento de energia para o transceptor pelos ultracapacitores. / This work presents the conception, design and implementation of a DC/DC boost converter to
connect a photovoltaic panel to a bank of ultracapacitors for energy storage to replace the
conventional automotive batteries. In the output of ultracapacitors a DC/DC step-down
converter is used. This converter provides power to a telecommunication system for the
supply of a single channel transceiver with the purpose of providing the services of rural
telephony and Internet in isolated communities from the public energy grid. The system can
provide the communication service to a isolated community from the power grid for up to
three hours at night when used with radio equipment with cables, connectors and antenna for
transmitting and receiving phone signal with consumption power of 13 W and with solar
radiation rate of 5.500 W/m2/day. During the day solar energy is captured by a photovoltaic
panel and stored in ultracapacitors through a boost converter. This converter enables
ultracapacitors to charge at the maximum power point (MPP) of the photovoltaic panel. The
transceiver is activated when the phone is taken off the hook and the system power comes
from the panel via ultracapacitors. If there are calls during the day, the photovoltaic panel
meets the needs of the transceiver. At night, the panel used does not generate enough energy
to power the telecommunication system. At night, if there is a phone call to the proposed
system, the transceiver will be triggered, and the subscriber should take the handset off the
hook to answer an incoming call. During this operation, the transceiver consumes
approximately 13 W of power, which is provided by ultracapacitors that are interconnected
through the buck converter. The proposed system is controlled by a microcontroller and a
control circuit which tracks the maximum power point (MPP) of the photovoltaic panel,
monitors the voltage level of ultracapacitors and determines the operating time of the DC/DC
converter which enables the provision of power to the transceiver by the ultracapacitors.This work presents the conception, design and implementation of a DC/DC boost converter to
connect a photovoltaic panel to a bank of ultracapacitors for energy storage to replace the
conventional automotive batteries. In the output of ultracapacitors a DC/DC step-down
converter is used. This converter provides power to a telecommunication system for the
supply of a single channel transceiver with the purpose of providing the services of rural
telephony and Internet in isolated communities from the public energy grid. The system can
provide the communication service to a isolated community from the power grid for up to
three hours at night when used with radio equipment with cables, connectors and antenna for
transmitting and receiving phone signal with consumption power of 13 W and with solar
radiation rate of 5.500 W/m2/day. During the day solar energy is captured by a photovoltaic
panel and stored in ultracapacitors through a boost converter. This converter enables
ultracapacitors to charge at the maximum power point (MPP) of the photovoltaic panel. The
transceiver is activated when the phone is taken off the hook and the system power comes
from the panel via ultracapacitors. If there are calls during the day, the photovoltaic panel
meets the needs of the transceiver. At night, the panel used does not generate enough energy
to power the telecommunication system. At night, if there is a phone call to the proposed
system, the transceiver will be triggered, and the subscriber should take the handset off the
hook to answer an incoming call. During this operation, the transceiver consumes
approximately 13 W of power, which is provided by ultracapacitors that are interconnected
through the buck converter. The proposed system is controlled by a microcontroller and a
control circuit which tracks the maximum power point (MPP) of the photovoltaic panel,
monitors the voltage level of ultracapacitors and determines the operating time of the DC/DC
converter which enables the provision of power to the transceiver by the ultracapacitors.This work presents the conception, design and implementation of a DC/DC boost converter to
connect a photovoltaic panel to a bank of ultracapacitors for energy storage to replace the
conventional automotive batteries. In the output of ultracapacitors a DC/DC step-down
converter is used. This converter provides power to a telecommunication system for the
supply of a single channel transceiver with the purpose of providing the services of rural
telephony and Internet in isolated communities from the public energy grid. The system can
provide the communication service to a isolated community from the power grid for up to
three hours at night when used with radio equipment with cables, connectors and antenna for
transmitting and receiving phone signal with consumption power of 13 W and with solar
radiation rate of 5.500 W/m2/day. During the day solar energy is captured by a photovoltaic
panel and stored in ultracapacitors through a boost converter. This converter enables
ultracapacitors to charge at the maximum power point (MPP) of the photovoltaic panel. The
transceiver is activated when the phone is taken off the hook and the system power comes
from the panel via ultracapacitors. If there are calls during the day, the photovoltaic panel
meets the needs of the transceiver. At night, the panel used does not generate enough energy
to power the telecommunication system. At night, if there is a phone call to the proposed
system, the transceiver will be triggered, and the subscriber should take the handset off the
hook to answer an incoming call. During this operation, the transceiver consumes
approximately 13 W of power, which is provided by ultracapacitors that are interconnected
through the buck converter. The proposed system is controlled by a microcontroller and a
control circuit which tracks the maximum power point (MPP) of the photovoltaic panel,
monitors the voltage level of ultracapacitors and determines the operating time of the DC/DC
converter which enables the provision of power to the transceiver by the ultracapacitors.
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Analysis of alternative energy options for buildingsRezaie, Behnaz 01 August 2009 (has links)
The importance of utilizing different types of energy and their technical application
is discussed. Awareness around the globe about the world energy crisis and its critical
environmental condition has put more emphasis on the use of renewable energies in
every corner of life. It is a well‐known fact that global warming, inefficient use of energy
and greenhouse gases are damaging the environment, species and human life drastically.
These issues will be discussed in recently conducted research.
To address the crucial state of our environment, two simultaneous scenarios are
considered. Initially, energy conservation and the switch to a low carbon/no carbon fuel
are studied. As for energy conservation in buildings, smart methods in the use of energy in
buildings are discussed. Based on different research reported, humans must change their
attitude toward the use of resources, and in particular, be conscientious about energy
consumption. Next, renewable energy promises a suitable alternative to energy needs in
this century, and the best means to overcome the environmental issue and energy crisis is
discussed. The practical methods of calculation for solar technology equipment, ground
source heat pumps, and wind turbines are explained. In the application part of the study,
four buildings are chosen as case studies; two of them from residential sectors, one is a
commercial/institutional building, and the fourth is an industrial building. A ground source
heat pump for heating and cooling, a solar water heater for heating space or hot water,
and a photovoltaic panel for generating electricity are designed for the case studies. Even
projects under hybrid systems combined from two technologies are designed. 36 different
energy options are calculated for the four case studies. Results show that if a target is
reducing CO2 emissions, what systems are the best. In contrast, when decision making is
based on budget, what system is the first choice? Not only are technology, environmental
protection and cost the main parameters for deciding on renewable technologies, but so
are reliability, installation, maintenance and ease of use. Hence, renewable energy
systems are categorized based on a broad vision.
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Aplicação de algoritmos de busca do ponto de máxima potência e controladores lineares e/ou fuzzy para a regulação da tensão terminal de painéis fotovoltaicos / Application of maximum power point tracking algorithms and linear and/or nonlinear fuzzy logic control to regulate the voltage of photovoltaic panelsNilton Eufrázio Martinho Moçambique 06 June 2012 (has links)
Algoritmos de busca do ponto de máxima potência (MPPT) são largamente utilizados para se obter a potência máxima fornecida em sistemas fotovoltaicos. Apesar de existirem diversas técnicas de MPPT, os métodos heurísticos de busca como o método da perturbação e observação (P&O) e o método da Condutância Incremental (InC) são os mais usuais por serem simples e confiáveis. Assim, é proposto uma lei de controle com realimentação da tensão de saída de um painel fotovoltaico (PV) de forma a manter o mesmo operando próximo ao ponto de máxima potência, possibilitando com isso uma melhora do desempenho do algoritmo de P&O e InC inclusive quando o painel PV é submetido a rápidas mudanças na irradiação solar. Além disso, devido às características não lineares dos painéis fotovoltaicos, a utilização de técnicas inteligentes que empregam controladores fuzzy para o controle da tensão terminal do PV, parece ser uma solução viável quando comparada aos controladores clássicos com PI e PID, principalmente, porque tais estruturas de controle proporcionam uma lenta resposta dinâmica e problemas de estabilidade relacionados às oscilações em torno do ponto de máxima potência, decorrente do funcionamento dos algoritmos P&O e InC. / Maximum power point tracking (MPPT) techniques are widely used to achieve the maximum output power of a photovoltaic (PV) system. Although there are many MPPT techniques, the heuristic search methods such as perturb and observe (P&O) and incremental conductance (InC) method are the most commonly used because they are simple and reliable in the pursuit of maximum power point. A control law with feedback of the output voltage of a photovoltaic (PV) panel is proposed, in order to maintain it working nearby the maximum power point, enabling an improvement in the performance of the algorithm for P&O and InC even when the PV array is subjected to rapid changes in solar irradiance. Moreover, due to the nonlinear characteristics of the photovoltaic panels, the technique that employ fuzzy logic control seems to be a viable option when compared with conventional proportional and integral or proportional, integral and derivative controllers, mainly because such control structures provide a slow dynamic response and stability issues related to oscillations around the maximum power point due to operation of P&O and InC algorithms.
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Tecnologias Sustentáveis: a importância dos telhados verdes na amenização microclimática / Sustainable Technologies: the importance of green roofs to soothe microclimateAranha, Kaline Cunha 29 February 2016 (has links)
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Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the different environmental problems that affect urban centres, we face the increase on temperature and the decrease on relative humidity on cities. The formation of heat islands and the thermal discomfort are changes observed in the urban thermal area of the cities climatic system, with serious problems to the general population. In this context, this work has as its main aim to verify the thermal performance of the green roof in analogy to other three toppings commonly used in civil construction (ceramic tile, cement tile and exposed slab). It was verified the thermal behaviour of the photovoltaic panels with the green roofs – hybrid roof. The research also had as a challenge to construct all the prototypes for microclimate monitoring. The microclimate monitoring happened in two different periods: dry and rainy season. To record the air temperature data, thermal hidrometers were used for inside measurements, and thermocouples to external measurement in photovoltaic panels. During the rainy season, the difference of up to 2° C was registered comparing the green roof to the cement tile prototype, and to the others the difference was 1°C. In the dry season the heat difference was 3° C related to the cement tile prototype, and 2° C when compared to the other toppings. In relation to external measurements done with the Thermocouples, the results are positive both on the superior or on the inferior surface of the Panel. That is, it was observed that the green roof contributes to soothe microclimate on the external environment, and consequently to the efficiency of the Panel. With these results, it is concluded that the green roof is a sustainable technology that helps soothing microclimate, on the internal and on the external environment. / Dentre os diversos problemas ambientais que afetam os centros urbanos, pode-se verificar o aumento de temperaturas e a redução da umidade relativa do ar nas cidades. A formação das ilhas de calor e o desconforto térmico são alterações observadas no campo térmico urbano do sistema climático das cidades com graves problemas para população em geral. Diante deste contexto, esta pesquisa se insere com o objetivo principal de verificar o desempenho térmico do telhado verde em analogia a outros três tipos de coberturas comumente usados na construção civil (telha cerâmica, fibrocimento, laje exposta). E verificou-se o comportamento térmico do painel fotovoltaico com o telhado verde – Telhado Híbrido. A pesquisa também teve o desafio de confeccionar todos os protótipos para o monitoramento microclimático. O monitoramento microclimático ocorreu em dois períodos climáticos distintos: período seco e chuvoso. Para os registros dos dados de temperatura do ar foram utilizados termohigrometros para medições internas. E termopares para medições externas no painel fotovoltaico. No período chuvoso, registra-se a diferença de até 2°C do telhado verde em relação ao protótipo com telha de fibrocimento e 1°C em relação aos demais. No período seco a diferença térmica foi de 3°C em relação ao protótipo de Fibrocimento e 2°C quando comparado aos demais. Com relação às medições externas feitas por termopares verificou-se que os resultados são positivos, tanto na superfície superior quanto na superfície inferior do painel. Ou seja, observa-se- que o telhado verde contribui com a amenização microclimática do ambiente externo e consequentemente com a eficiência do painel. Com estes resultados, conclui-se que o telhado verde é uma tecnologia sustentável que contribui com a amenização microclimática interna e externa do ambiente.
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Analise comparativa de sistemas de armazenamento de energia eletrica fotovoltaica por meio de baterias e hidrogenio em localidades isoladas da região Amazonica / Comparative analysis of photovoltaic power storage systems by means of batteries and hydrogen in remote areas of the Amazon region of BrazilFurlan, André Luís 12 August 2018 (has links)
Orientador: Newton Pimenta Neves Jr. / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-12T23:02:40Z (GMT). No. of bitstreams: 1
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Previous issue date: 2008 / Resumo: Neste trabalho foram feitas análises comparativas entre as formas de armazenamento de energia elétrica fotovoltaica pela forma tradicional, através de baterias de chumbo-ácido, e por meio de hidrogênio eletrolítico para posterior reconversão em eletricidade utilizando células a combustível. Para tanto, foi desenvolvido um modelo matemático para o dimensionamento dos sistemas, implementado numa planilha eletrônica, onde foram consideradas as principais características e eficiências dos equipamentos que compõem os sistemas, bem como o perfil de carga característico das comunidades da Região Amazônica. A seguir, foi realizada uma análise econômica de ambos os sistemas para uso em comunidades isoladas, tendo sido verificado que nas condições estabelecidas o sistema utilizando baterias apresenta uma vantagem de 20%. No entanto, observou-se que uma redução de aproximadamente 35% nos custos do conjunto eletrolisador/reservatório/célula a combustível, tecnologias ainda em processo de grande evolução tecnológica, torna o sistema a hidrogênio bastante competitivo, podendo-se constituir na melhor opção para o armazenamento de energia de origem fotovoltaica, principalmente devido aos riscos ambientais associados ao manejo de grandes bancos de baterias em regiões isoladas / Abstract: In this work, comparative analyses of photovoltaic power storage were made, first by the traditional means employing lead-acid batteries, and second by means of electrolytic hydrogen which was later reconverted to power in a fuel cell. In order to design the two systems, it was used a load profile of the communities in Amazon region and by means of a mathematical model, implemented in a spreadsheet, that considers the several devices and their efficiencies in order to make it possible to specify the system components. This was followed by an economical analysis of the two systems for use in remote communities. Considering the present conditions, it was verified that the battery system is 20% more advantageous. However, it was also observed that a reduction of about 35% in the cost of the electrolyzers/buffer/fuel cell, technologies still in processes of development, would make the hydrogen system very competitive, becoming the best option for photovoltaic power storage, especially due to the environmental risks associated with the use of large battery banks in remote regions / Mestrado / Mestre em Planejamento de Sistemas Energéticos
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Chemické složení fotovoltaických panelů a jejich rizikovost / Chemical composition of photovoltaic panels and assessment of their environmental risksKoudelová, Marta January 2017 (has links)
The diploma work deals with chemical composition of photovoltaic panels and assessment of their environmental risks. In its introduction part, the characterization of photovoltaic panels, including the composition of their layers and the significance of some specific metals in these facilities, is summarized. The introduction part also mentions the life cycle of photovoltaic panels from production to end of life. The experimental part is focused on chemistry of several different types of photovoltaic panels. In addition to the major elements of the panels (Si, Al, Fe, Na, Ca), the analyzes confirmed the increased content of interest metals (especially Cu, Ag, Sb, Sn, Zn, Pb) at tens to thousands of mg/kg depending on the processed sample. A potentially economically interesting value is Ag. The Ag concentrations range from hundreds to 1,300 mg/kg (~ 1,200 g Ag / t of panels) for some types of processed samples. High concentrations exhibit Cu (up to 16,700 mg/kg), Sb (up to 1,890 mg/kg) or Sn (up to 2050 mg/kg). Leaching experiments (using deionized water and EDTA reagents) were performed at two time intervals (24 and 168 hours). Very low leachability of the metals from the studied samples (in order of per mil or less) has been demonstrated. The studied samples of photovoltaic panels can be classified...
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