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

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Includes bibliographical references. / by Paolo Rava. / Ph.D.

No description available.

Wong, Man Keung. / "November 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Abstracts in English and Chinese. / Abstract --- p.i / Table of contents --- p.iii / List of Figures --- p.vi / List of Tables --- p.ix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- History of organic photovoltaic cells --- p.2 / Chapter 1.2.1 --- Single layer organic photovoltaic cells --- p.2 / Chapter 1.2.2 --- Bilayer organic photovoltaic cells --- p.3 / Chapter 1.2.3 --- Bulk Heterojunction organic photovoltaic cells --- p.6 / Chapter 1.3 --- Device physics of organic photovoltaic cells --- p.9 / Chapter 1.4 --- Device fabrication and characterization --- p.12 / Chapter 1.5 --- Thesis outline --- p.14 / Chapter Chapter 2 --- Instrumentation --- p.18 / Chapter 2.1 --- Keithley 236 source measure unit --- p.18 / Chapter 2.2 --- CHI 660C electrochemical instrument --- p.18 / Chapter 2.3 --- Tensor Alpha Step 500 Profilometer --- p.19 / Chapter 2.4 --- Fourier Transform Infrared (FTIR) spectroscopy --- p.20 / Chapter 2.5 --- Thermogravimetric Analysis --- p.22 / Chapter 2.6 --- X-ray Diffraction --- p.23 / Chapter 2.7 --- Scanning electron microscopy --- p.24 / Chapter 2.8 --- Atomic force microscopy --- p.26 / Chapter Chapter 3 --- Surface functionalization of Carbon Nanotube --- p.28 / Chapter 3.1 --- Introduction --- p.28 / Chapter 3.2 --- Oxidative treatment --- p.28 / Chapter 3.2.1 --- Experimental procedures --- p.28 / Chapter 3.2.2 --- Characterization --- p.29 / Chapter 3.3 --- Hydrothermal treatment --- p.35 / Chapter 3.3.1 --- Experimental procedures --- p.35 / Chapter 3.3.1.1 --- Synthesis of MWCNTols --- p.35 / Chapter 3.3.1.2 --- Synthesis of MWCNT-PEDOT --- p.36 / Chapter 3.3.2 --- Characterization --- p.37 / Chapter 3.4 --- Summary --- p.42 / Chapter Chapter 4 --- P3HT/f-CNT/PCBM Composites for Organic Photovoltaic Cells --- p.45 / Chapter 4.1 --- Introduction --- p.45 / Chapter 4.2 --- Fabrication procedures --- p.48 / Chapter 4.3 --- IV characteristics of organic photovoltaic cells --- p.51 / Chapter Chapter 5 --- Vertically aligned poly(3-hexylthiophene) nanobrushes of high aspect ratio for photoelectrochemical solar cells --- p.60 / Chapter 5.1 --- Introduction --- p.60 / Chapter 5.2 --- Sample preparation --- p.63 / Chapter 5.3 --- IV characteristics of P3HT nanobrushes --- p.65 / Chapter 5.4 --- AFM and XRD analysis --- p.66 / Chapter 5.5 --- Summary --- p.71 / Chapter Chapter 6 --- Conclusions --- p.74 / Chapter 6.1 --- Conclusions --- p.74

The design processes for solar photovoltaic (PV) systems is improved to achieve higher reliability and reduced levelised cost of energy (LCOE) throughout this thesis. The design processes currently used in the development of PV systems are reviewed. This review process included embedding the author in a project to deliver four rooftop PV systems which totalled a megawatt of installed generating capacity, which at the time represented very significant system sizes. The processes used in this are analysed to identify improvement potential. Shortcomings are identified in three main areas: safety assurance, design process integration and financial optimisation. Better design process integration is required because data is not readily exchanged between the industry standard software tools. There is also a lack of clarity about how to optimise design decisions with respect to factors such as shading and cable size. Financial optimisation is identified as a challenge because current software tools facilitate optimising for maximum output or minimum cost, but do not readily optimise for minimum levelised cost of energy which is the primary objective in striving for grid parity. To achieve improved design process integration and financial optimisation, a new modelling framework with the working title SolaSIM is conceived to accurately model the performance of solar photovoltaic systems. This framework is developed for grid connected systems operating in the UK climate, but it could readily be adapted for other climates with appropriate weather data. This software development was conducted using an overarching systems engineering approach from design and architecture through to verification and validation. Within this SolaSIM framework, the impact of shading on array and inverter efficiency is identified as a significant area of uncertainty. A novel method for the calculation of shaded irradiance on each cell of an array with high computational efficiency is presented. The shading sub-model is validated against outdoor measurements with a modelling accuracy within one percent. Final verification of the over-arching SolaSIM framework found that it satisfied the requirements which were identified and actioned. The author installed the new CREST outdoor measurement system version 4 (COMS4). COMS4 is a calibrated system which measures 26 PV devices simultaneously. Validation of SolaSIM models against COMS4 found the modelling error to be within the 4% accuracy target except two sub-systems which had electronic faults. The model is validated against PV systems and found to be within the specified limits.

In the effort to reduce the release of harmful gases associated with the transportation sector, Plug-in Electric Vehicles (PEV) have been deployed on the account of zero-tail pipe emissions. With electrification of transport it is imperative to address the electrical grid emissions during vehicle charging by motivating the use of distributed generation. This thesis employs optimal charging strategies based on solar availability and electrical grid tariffs to minimize the cost of retrofitting an existing parking lot with photovoltaic (PV) and PEV infrastructure. The optimization is cast as a unit-commitment problem using the CPLEX optimization tool to determine the optimal charge scheduling. The model determines the optimal capacity of system components and assesses the techno-economic feasibility of PV infrastructure in the microgrid by minimizing the net present cost (NPC) in two case studies: Victoria, BC and Los Angeles, CA. It was determined that due to a relatively low grid tariff and scarcity of solar irradiation, it is not economically feasible to install solar panels and coordination of charging reduces the operating cost by 11% in Victoria. Alternatively, with a high grid tariff and abundance of solar radiation, it shown that Los Angeles is a promising candidate for PV installations. With the implementation of a charging coordination scheme in this region, NPC savings of 8-16% are simulated with the current prices of solar infrastructure. Additionally, coordinated charging was assessed in conjunction with various commercial buildings posing as a base load and it was determined that the effects of coordination were more prominent with smaller base loads. / Graduate

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This research describes the process of obtaining a photovoltaic cell, since getting electrical conductor glasses used for the flow of electrons coming from the photovoltaic effect until the deposition of thin films of semiconductor titanium dioxide (TiO2) and cadmium sulfide (CdS) at each of these glasses. The use of natural or synthetic dyes deposited on titanium dioxide layer has the objective to increase the absorption spectrum of the TiO2, since sunlight emits most of its energy in the frequency range of visible light. After joining the two glasses with thin films deposited over TiO2 plus dye and CdS, it was used a potassium triiodide electrolyte for regeneration and consequently the activation of photovoltaic solar cell. After mounting the cell concerned, tests of photoactivity have been performed by exposing the cells to sunlight collected for specified periods and the values of voltage and photocurrent generated. Theoretical studies have been conducted to mathematical modeling of the behavior of the solar cell mounted, and then we have analyzed the efficiency of converting solar energy into electrical energy. The constituents of the cell have been characterized by the techniques of X-ray diffraction (XRD) and scanning electron microscopy (SEM) for analyzing the porosity, uniformity and other physical parameters of thin films. / O presente trabalho descreve o processo de obtenÃÃo de uma cÃlula fotovoltaica, desde a obtenÃÃo de vidros condutores elÃtricos utilizados para o fluxo dos elÃtrons oriundos do efeito fotovoltaico, atà a deposiÃÃo dos filmes finos dos semicondutores diÃxido de titÃnio (TiO2) e sulfeto de cÃdmio (CdS) em cada um dos vidros. O uso de corantes naturais ou sintÃticos na camada depositada de diÃxido de titÃnio possuiu como objetivo aumentar o espectro de absorÃÃo do mesmo, uma vez que a luz solar emite uma grande parte de sua energia na faixa de frequÃncia da luz visÃvel. Depois de unir os dois vidros com os filmes finos depositados de TiO2 mais corante e o CdS, utilizou-se o eletrÃlito de tri-iodeto de potÃssio para a regeneraÃÃo e consequentemente a ativaÃÃo da cÃlula solar fotovoltaica. ApÃs a montagem da cÃlula em questÃo, foram realizados testes de fotoatividade, expondo as cÃlulas ao sol por perÃodos determinados e coletados os valores da fotocorrente gerada e a tensÃo, alÃm disso, foram realizados estudos teÃricos para modelagem matemÃtica do comportamento da cÃlula solar montada e em seguida analisou-se a eficiÃncia de conversÃo de energia solar em energia elÃtrica. Os constituintes da cÃlula foram caracterizados pelas tÃcnicas de difraÃÃo de raios-X (DRX) e microscopia eletrÃnica de varredura (MEV) para analisar a porosidade, uniformidade e outros parÃmetros fÃsicos dos filmes finos.

Este trabalho apresenta o desenvolvimento de uma metodologia para a etiquetagem e qualificação de inversores para Sistemas Fotovoltaicos Conectados à Rede, com finalidade de servir de proposta de procedimento para inclusão no Regulamento de Avaliação de Conformidade de Equipamentos e Sistemas Fotovoltaicos do Programa Brasileiro de Etiquetagem. O procedimento desenvolvido avalia os inversores quanto à eficiência, qualidade de energia, proteções e informações operacionais e de instalação. / This work presents the development of a methodology for qualification and labeling of inverters for grid-connected photovoltaic systems, aiming serving as procedural proposal for inclusion in the Conformity Assessment Rules of Equipments and Photovoltaic Systems of the Brazilian Labeling Program. The developed procedure evaluates the inverters efficiency, power quality, protections and operational and installation information.

Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, 2018. / Gas turbines have achieved widespread popularity in industrial fields. This is due to the high power, reliability, high efficiency, and its use of cheap gas as fuel. However, a major draw-back of gas turbines is due to the strong function of ambient air temperature with its output power. With every degree rise in temperature, the power output drops between 0.54 and 0.9 percent. This loss in power poses a significant problem for utilities, power suppliers, and co-generations, especially during the hot seasons when electric power demand and ambient temperatures are high. One way to overcome this drop in output power is to cool the inlet air temperature. There are many different commercially available means to provide turbine inlet cooling. This disserta-tion reviews the various technologies of inlet air cooling with a comprehensive overview of the state-of-the-art of inlet fogging systems. In this technique, water vapour is being used for the cooling purposes. Therefore, the water quality requirements have been considered in this thesis. The fog water is generally demin-eralized through a process of Reverse Osmosis (RO). The drawback of fogging is that it re-quires large amounts of demineralized water. The challenge confronting operators using the fogging system in remote locations is the water scarcity or poor water quality availability. However, in isolated hot areas with high levels of radiation making use of solar PV energy to supply inlet cooling system power requirements is a sustainable approach. The proposed work herein is on the development of a photovoltaic (PV) application for driv-ing the fogging system. The design considered for improved generation of Acaica power plant in Cape Town, South Africa. In addition, this work intends to provide technical infor-mation and requirements of the fogging system design to achieve additional power output gains for the selected power plant.

This research is concerned with the drivers to utilize Renewable Energy in Gulf Cooperation Council countries with a focus on Kuwait. Such countries show high rates of electricity subsidies with high rate of emissions. At present, there is a continuous need to build new power stations to increase the electrical capacities, in order to cover the high peak loads that occurs in summers to avoid blackouts. The aim of this research is to create a combination of approaches to assess the adoption (economic and environmental) of Photovoltaic for electricity generation in Kuwait, which can be used to assist policy makers to compare various energy mixes and hence determine whether their current and future strategies are appropriate. Kuwait is in this research representative of an exemplar of oil-based economy in Gulf Cooperation Council region since they share similar energy policies and geographic location. The research provides an insight into the adoption of renewables in the region and the impact that particular energy mixes may have. Nine future potential scenarios are created showing different levels of PV deployment within Kuwait. The combination of approaches in this research estimates the economic and environmental impacts using Levelized Cost of Electricity and Life Cycle Assessment respectively of differing RE mixes. The findings show that energy storage increases the cost of electricity and the emissions from the photovoltaic sector. However, for the energy mix (PV and conventional), assuming oil price greater than 10.1$/Bbl. (when no storage required) and 15.2$/Bbl. (when using storage), PV generally lowers the cost of electricity, CO2 and SO2 emissions. Whilst, human toxicity is increased when storage is used. Taking all these factors into account, PV deployment is generally beneficial. However, if different combinations of impacts are considered, environmental and economic impacts may take different patterns. This led to a multi-objective problem to be solved. Using Pareto Front analysis, scenarios without storage requirement (i.e. 13% or less of photovoltaic) are preferable if only cost and human toxicity are considered. The contribution to knowledge from this research is that the deployment of large scale PV technology is beneficial in Kuwait economically and environmentally at least until 30% of the maximum peak load of electricity. The results have implications for other GCC countries with similar geographical, political and energy drivers; the methodology used in this research would be appropriate for these contexts.