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Μελέτη/κατασκευή υβριδικού συστήματος (κυψέλη υδρογόνου και PV στοιχείων) και της συμπεριφοράς των διατάξεων προστασίαςΣταθόπουλος, Κωνσταντίνος 07 June 2013 (has links)
Η ενεργειακή κρίση που προκάλεσε η χρήση των υδρογονανθράκων ως κύρια πηγή παραγωγής ενέργειας, η προσπάθεια κάθε κράτους για απεξάρτηση του από τις πετρελαιοπαραγωγικές χώρες αλλά και η ανάγκη για μορφές ενέργειας χωρίς αρνητική επίδραση στο περιβάλλον οδήγησαν στην ανάπτυξη των ανανεώσιμων μορφών ενέργειας.
Για την εμπορική τους, όμως, εκμετάλλευση ήταν απαραίτητη η επίλυση των τεχνικών προβλημάτων που εμφανίστηκαν, ιδιαίτερα όσο αναφορά τη σύνδεση κατανεμημένων παραγωγών με το υπάρχον ηλεκτρικό δίκτυο.
Tο φαινόμενο της νησιδοποίησης (islanding), δηλαδή η μη διακοπή της παροχής ηλεκτρικού ρεύματος στο διασυνδεδεμένο δίκτυο από το κατανεμημένο παραγωγό όταν αυτός έχει αποσυνδεθεί από το κεντρικό δίκτυο, με κίνδυνο για τους εργαζόμενους και τις εκάστοτε συνδεδεμένες σε αυτόν συσκευές, πρέπει να αντιμετωπίζεται άμεσα.
Σκοπός της εργασίας αυτής είναι η θεωρητική σύγκριση των προτεινόμενων τεχνικών ελέγχου νησιδοποίησης, η επιλογή και η προσομοίωση στο ATP-EMTP της καταλληλότερης από αυτές.
Στο πρώτο κεφάλαιο αναλύεται η σημερινή κατάσταση όσο αναφορά την παραγωγή ενέργειας από την κάθε ανανεώσιμη πηγή ενέργειας και τονίζεται η εξέχουσα θέση και η επικράτηση της ηλιακής ενέργειας και των φωτοβολταϊκών συστημάτων.
Στο δεύτερο κεφάλαιο αναπτύσσεται το φαινόμενο της νησιδοποίησης και μια σειρά από προτεινόμενες τεχνικές ανίχνευσης και διακοπής της νησιδοποίησης.
Στο τρίτο κεφάλαιο αναλύονται οι τεχνικές με χρήση άεργου ισχύος και γίνεται θεωρητική ανάλυση της επιλεγμένης RPV μεθόδου.
Στο τέταρτο και πέμπτο κεφάλαιο περιγράφονται οι δυνατότητες του ATP-EMTP, η προσομοίωση της μεθόδου και τα αποτελέσματα που προέκυψαν. Τέλος η εργασία ολοκληρώνεται από τα συμπεράσματα μετά την προσομοίωση σχετικά με την επιλογή της συγκεκριμένης μεθόδου και το φαινόμενο της νησιδοποίησης. / The energy crisis caused by the use of oil as a primary source of energy, the effort of each state to detox from oil-producing countries and the need for energy without negative impact on the environment has led to the development of renewable sources of energy.
For their commercial exploitation though, it was necessary to solve the technical problems that occurred, particularly about connecting distributed generation with the existing power grid.
The phenomenon of islanding (islanding), the electrical supply from distributed generation is not interrupted when it is disconnected from the main-grid, with a risk for employees and equipment connected on this, should be dealt with.
The purpose of this work is the theoretical comparison of the proposed islanding control techniques, selection and simulation in ATP-EMTP of the one that is the most appropriate of them.
In the first chapter the present status report of energy production from each renewable energy source and highlights the prominence and prevalence of solar energy and photovoltaics are analyzed.
During the second chapter the phenomenon of islanding is described and a number of proposed techniques for detecting and preventing islanding.
In the third chapter the techniques using reactive power are analyzed and the theoretical analysis of the selected RPV method is presented.
In the fourth and fifth chapter the possibilities of ATP-EMTP are described, the simulation method and its results are presented. Finally the work is concluded by the results after the simulation on the selection of this particular method and the phenomenon of islanding.
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Sistemas fotovoltaicos domiciliares de dessalinização de água para consumo humano: um estudo de sua viabilidade e configurações / Household photovoltaic desalination systems for drinking water production: a study of its viability and settings.Daniel Jordão de Magalhães Rosa 13 December 2013 (has links)
Grande parte da população rural do Semiárido brasileiro sofre com problemas de acesso à água de qualidade. A exploração da água subterrânea representa uma das principais alternativas para o abastecimento dessa parcela da população, mas muitas vezes os poços perfurados encontram-se longe da rede elétrica. A região apresenta abundante recurso solar e, assim, essa dificuldade poderia ser contornada com a utilização de sistemas fotovoltaicos de bombeamento. Mas, além da questão da energia para o funcionamento dos sistemas de bombeamento, pelo fato da maior parte do Semiárido estar localizada sobre escudo cristalino, muitos poços apresentam água com altos níveis de salinidade, o que inviabiliza a utilização desses mananciais para o fornecimento de água potável ou faz com que a população rejeite seu consumo, por conta do gosto. O presente trabalho tem como objetivo verificar se a adaptação de sistemas de dessalinização de pequeno porte disponíveis comercialmente a sistemas fotovoltaicos domiciliares pode potencializar a difusão dos sistemas fotovoltaicos de bombeamento em poços de água com alto teor de sais dissolvidos e se essa opção pode representar uma alternativa de fornecimento de água para a população rural de áreas com problemas de salinização dos mananciais de abastecimento. A opção analisada consiste em um sistema duplo de fornecimento de água, com tratamento do tipo ponto de uso da água para consumo humano. Foi verificado que os sistemas de dessalinização atualmente disponíveis no mercado podem funcionar acoplados a geradores fotovoltaicos e utilizados para fornecimento de água potável a partir de água salobra. / Much of the rural population of the Brazilian Semiarid region suffers from problems related to access of improved water quality. The exploitation of ground water is the main alternative for water supply solutions regarding this population, but often the boreholes are away from power lines. The region has abundant solar source and therefore this problem could be overcome with the use of photovoltaic pumping systems. Beyond the issue of energy for operation of the borehole systems, considering that most of the semiarid region is located on crystalline shield, many boreholes have water with high level of salinity, which hinder their use for drinking water supply solutions, as the population rejects the water because of its taste. This study aims to determine whether the adaptation of commercially available small household desalinization systems adapted to photovoltaic systems can enhance the diffusion of photovoltaic pumping systems of boreholes with high concentrations of dissolved salt, by proposing this water supply solution as an alternative for water supply systems in rural areas with problems of salinization of the main water sources. The proposed technical solution consists of a dual water supply system with the use a point of use water treatment for human consumption. It was found that desalination systems available on the market can operate coupled to photovoltaic generators and used to supply drinking water from brackish water.
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Avaliação do impacto de sistemas fotovoltaicos conectados à rede de distribuição de baixa tensão / Evaluation of grid connected photovoltaic systems impact on low voltage electrical gridAimé Fleury de Carvalho Pinto Neto 09 September 2016 (has links)
Este trabalho apresenta a avaliação dos impactos elétricos da inserção da geração distribuída de sistemas fotovoltaicos conectados à rede de distribuição em baixa tensão, com a finalidade de identificar os impactos e demonstrar que estes podem ser controlados. O estudo consistiu de uma avaliação teórica e de um estudo de caso da inserção da geração fotovoltaica considerando aspectos da qualidade de energia da rede, curva de carga resultante, vida útil de transformadores e gestão ativa da demanda. Os resultados mostraram que a inserção da geração fotovoltaica na rede de baixa tensão altera a curva de carga da unidade consumidora, mas que essas alterações podem ser controladas pela gestão ativa da demanda utilizando armazenamento de energia. Os resultados também mostraram que a geração fotovoltaica também afeta a tensão e o fator de potência da unidade consumidora, mas que essas alterações podem ser controladas pela produção de potência reativa pelo inversor. Além disso, verificou- se que a geração fotovoltaica não afetou a distorção harmônica de tensão da rede e que aumentou a vida útil do transformador. / This work presents the evaluation of grid connected photovoltaic systems\' impact on low voltage electrical grid, in order to identify the impacts and demonstrate that it can be controlled. The study consisted of a theoretical evaluation and of a case study of photovoltaic generation inclusion considering aspects of grid power quality, resulting load curve, lifespan of transformers and demand side management. The results showed that the inclusion of photovoltaic generation in low voltage network changes the load curve of the consumer unit, but these changes can be controlled by demand side management using energy storage. The results also showed that the photovoltaic generation also affects the voltage and the power factor of the consumer unit, but these changes can be controlled by the production of reactive power by the inverter. Furthermore, it was found that the photovoltaic generation does not affect the voltage harmonic distortion of the mains and it increases the lifespan of the transformer.
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Levantamento do potencial de geração fotovoltaica com sistemas de microgeração aplicados à arquitetura nos edifícios do Campus São Paulo da USP / Survey of the photovoltaic generation potential with microgeneration systems applied to architecture on the buildings of São Paulo campus of USPMario Luiz Ferrari Pin 21 September 2017 (has links)
O objetivo deste trabalho foi determinar o potencial de geração fotovoltaica com sistemas de microgeração sobre os edifícios dentro do campus São Paulo da USP. As diferentes topologias de sistemas fotovoltaicos conectados à rede elétrica foram descritas, apresentando as vantagens e desvantagens de cada uma delas. Em 2012, com a edição da Resolução Normativa n°482 pela Agência Nacional de Energia Elétrica (ANEEL), tornam-se possíveis no Brasil a instalação de sistemas de geração de energia a partir de fontes renováveis, de forma distribuída, onde o consumidor conectado à rede de distribuição injeta energia na rede elétrica e com isso gera créditos que são usados nos meses subsequentes. A Resolução Normativa n° 687 da ANEEL e o Convênio 16 do CONFAZ, ambos de 2015, estabeleceram novas regras que tornaram a geração distribuída mais atrativa economicamente, o que resultou no crescimento do número de instalações de forma acelerada a partir desse ano. A usina fotovoltaica do Instituto de Energia e Ambiente é formada por quatro instalações distintas e tem uma potência instalada de 540 kWp. Os dados de produção e de desempenho do primeiro ano de operação das instalações que se encontram sobre a Biblioteca Brasiliana Guita e José Mindlin e do Instituto de Estudos Brasileiros foram utilizados para que parâmetros mais adequados fossem inseridos no simulador de sistemas fotovoltaicos SISIFO. Com esses parâmetros, juntamente com dados solarimétricos do projeto SWERA e meteorológicos do INMET utilizou-se o software SISIFO para simular a capacidade de produção de energia elétrica a partir de sistemas fotovoltaicos de microgeração sobre os edifícios identificados no campus. A capacidade anual de produção de energia elétrica calculada para esses sistemas é de 2.600 MWh o que corresponde a 3,1% do consumo total de eletricidade do campus entre abril de 2015 e maio de 2016. / The goal of this work was to determine the potential of photovoltaic generation with microgeneration systems on the buildings within the São Paulo campus of USP. The different topologies of on grid photovoltaic systems were described, presenting the advantages and disadvantages of each one of them. In 2012, with the issuance of Normative Resolution No. 482 by the National Electric Energy Agency (ANEEL), it became possible in Brazil to install power generation systems from renewable sources in a distributed way, where consumers connected to the distribution network injects power into the grid and thereby generates credits that are used in the subsequent months. The Normative Resolution N ° 687 of ANEEL and CONFAZ Agreement 16, both of 2015, established new rules that made distributed generation more economically attractive, which resulted in an accelerated growth of the number of installations as of this year. The photovoltaic power plant of the Institute of Energy and Environment is formed by four distinct installations and has an installed power of 540 kWp. The production and performance data of the first year of operation of the facilities located on the Brasiliana Guita and José Mindlin Library and the Brazilian Institute of Studies were used to set the most appropriate parameters to be inserted in the SISIFO photovoltaic system simulator. With these parameters, together with solarimetric data from the SWERA project and meteorological data from INMET, SISIFO was used to simulate the electricity production capacity from photovoltaic microgeneration systems on the identified campus buildings. The annual electricity production capacity calculated for these systems is 2,600 MWh which corresponds to 3.1% of total campus consumption of electricity between April 2015 and May 2016.
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Desempenho De Um Sistema De Irrigação Por Gotejamento Utilizando Energia Fotovoltaica / Performance of a Drip Irrigation System Using Photovoltaic EnergyZago, Emmanuelle Albara 22 February 2017 (has links)
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Previous issue date: 2017-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The focus of this project was the use of a water pumping system for drip irrigation. The energy for such pumping was obtained by means of a small-sized photovoltaic panel of Greatwatt's horizontal axis installed on a self-supporting tower and a water pump of the brand SHURflo model 8000, it was installed in the project CASA (Analysis Center Of Alternative Systems). The trials were performed on sunny days, and cloudy and with few clouds, at different times and duplicates at each time. The energy produced was collected directly at the site and the irrigation capacity was obtained by collecting the water and its uniformity estimated by means of the Christiansen Uniformity Coefficient (CUC) and the Uniform Distribution Coefficient (CUD); The yield of the system varied according to the characteristics of the tests. The open sky days presented the highest values in relation to the energy produced, with an average of up to 15.1 Wh. On the other hand, the values of CUC and CUD were within acceptable range, most of them considered excellent or greater than 90%. In this way, it is possible to verify the feasibility of the use of a photovoltaic solar system to obtain energy for irrigation in small properties in the municipality of Cascavel-PR. / O foco desse projeto foi a utilização de um sistema de bombeamento de água para irrigação por gotejamento. A energia para tal bombeamento foi obtida por meio de um painel fotovoltaico de pequeno porte de eixo horizontal da marca Greatwatt instalado sobre uma torre autoportante e uma bomba d’água da marca SHURflo modelo 8000, o mesmo foi instalado no projeto CASA (Centro de Analises de Sistemas Alternativos). Os ensaios foram realizados em dias de céu aberto, nublado e com poucas nuvens, em diferentes horários e duplicados a cada horário. A energia produzida foi coletada diretamente no local e a capacidade de irrigação foi obtida pela coleta da água e sua uniformidade estimada por meio do Coeficiente de Uniformidade de Christiansen (CUC) e do Coeficiente de Uniformidade de Distribuição (CUD); O rendimento do sistema apresentou variações de acordo com as características dos ensaios. Os dias de céu aberto apresentaram os maiores valores em relação à energia produzida, com média de até 15,1 Wh. Já os valores de CUC e CUD enquadraram-se dentro da faixa considerada aceitável, sendo a maioria deles considerado excelente ou maiores do que 90%. Desta maneira, pode-se verificar a viabilidade da utilização de um sistema solar fotovoltaico para obtenção de energia destinada a irrigação em pequenas propriedades no município de Cascavel-PR.
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Desenvolvimento de uma ferramenta computacional para o dimensionamento de sistemas fotovoltaicos isolados e interligados à rede / Development of a computational tool for system sizing photovoltaics isolated and interconnected gridPazuch, Félix Augusto 17 February 2017 (has links)
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Previous issue date: 2017-02-17 / The present work deals with the development of a computational tool for sizing of
photovoltaic systems connected to the network systems of the concessionaire
(Grid_tie) and isolated systems (Off_grid). The calculations for the scaling were
obtained from the Photovoltaic systems engineering Handbook – CRESESB,
technology, design and installation of photovoltaic systems – GREENPO and Digital
Book introduction to Solar Systems – BLUESOL. For both systems, the sizing step
that resembles the two configurations is the location information of the photovoltaic
project. Knowing the data of latitude, longitude and altitude of the site the tool
calculates the angle of the modules for better absorption of the photovoltaic radiation.
For systems connected to the network, it is also necessary to provide information on
the consumption of the building to be serviced by the photovoltaic system. For
isolated systems, besides the information of the place, it is necessary to know the
demand and consumption of the building. By means of a list of electrical equipment,
the equipment dependent on the photovoltaic system is defined. The decisionmaking
criteria are based on economic analysis, based on indices such as Net
Present Value (NPV), Internal Rate of Return (IRR) and Discounted Payback. As
results we presented the screens developed for the sizing tool and examples of
sizing of both photovoltaic systems through tables and graphs. The developed
application works in an uninterrupted manner without presenting problems and
proved to be reliable, since all the calculations are of the sizing algorithm or the
calculations of the economic analysis, they have a theoretical basis. / O presente trabalho trata do desenvolvimento de uma ferramenta computacional
para o dimensionamento de sistemas fotovoltaicos: sistemas interligados à rede da
concessionária (Grid_tie) e sistemas isolados (Off_grid). Os cálculos para o
dimensionamento foram obtidos do Manual de Engenharia para Sistemas
Fotovoltaicos – CRESESB, do Manual de Tecnologia, Projeto e Instalação de
Sistemas fotovoltaicos – GREENPO e do Livro Digital de Introdução aos Sistemas
Solares – BLUESOL. Para ambos os sistemas, a etapa do dimensionamento que se
assemelha as duas configurações é a informação do local do projeto fotovoltaico.
Conhecendo os dados de latitude, longitude e altitude do local a ferramenta calcula o
ângulo dos módulos para melhor absorção da radiação fotovoltaica. Para sistemas
conectados à rede é necessária ainda a informação do consumo da edificação que
vai ser atendida pelo sistema fotovoltaico. Para sistemas isolados, além das
informações do local, é necessário conhecer a demanda e o consumo da edificação.
Por meio de uma lista de equipamentos elétricos são definidos os equipamentos
dependentes do sistema fotovoltaico. Os critérios de tomada de decisão são
baseados em análise econômica, a partir de índices como Valor Presente Líquido
(VPL), Taxa Interna de Retorno (TIR) e Payback Descontado. Como resultados
foram apresentados as telas desenvolvidas para a ferramenta de dimensionamento
e exemplos de dimensionamentos de ambos os sistemas fotovoltaicos através de
tabelas e gráficos. O aplicativo desenvolvido funciona de forma ininterrupta sem
apresentar problemas e mostrou-se confiável, pois todos os cálculos sejam eles do
algoritmo de dimensionamento ou dos cálculos da análise econômica, possuem
embasamento teórico.
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Smart matrix converter-based grid-connected photovoltaic system for mitigating current and voltage-related power quality issues on the low-voltage gridGeury, Thomas 20 January 2017 (has links)
The increasing penetration of distributed energy resources, in particular Photovoltaic (PV) production units, and the ever-growing use of power electronics-based equipment has led to specific concern about Power Quality (PQ) in the Low-Voltage (LV) grid. These include high- and low-order current harmonics as well as voltage distortion at the point of common coupling. Solutions to overcome these issues, meeting international grid codes, are being proposed in the context of smart energy management schemes.This work proposes a novel three-phase topology for a PV system with enhanced PQ mitigation functionality, tackling the corresponding control challenges.First, a single-stage current-source inverter PV system with active filtering capability is preferred to the more common two-stage voltage-source inverter topology with additional voltage-step-up converter. The system also guarantees a nearly unitary displacement power factor in the connection to the grid and allows for Maximum Power Point Tracking (MPPT) with direct control of the PV array power. The grid-synchronised dq-axis grid current references are generated for the mitigation of nonlinear load low-order current harmonics, without the need for additional measurements. Active damping is used to minimise grid-side filter losses and reduce high-order harmonics resulting from the converter switching.Results on a 500W laboratory prototype confirm that active damping reduces the switching harmonics in the grid currents and active filtering properly mitigates the low-order current harmonics. The MPPT algorithm works effectively for various irradiance variations. Second, a PV system with a novel Indirect Matrix Converter (IMC)-based unified power quality conditioner topology is developed for enhanced current and voltage compensation capability, with compactness and reliability advantages. PQ issues such as current harmonics, and voltage sags, swells, undervoltage and overvoltage are mitigated by the shunt and series converters, respectively.The more common Space Vector Modulation (SVM) method used in IMCs is developed for this specific topology. In particular, a new shunt converter modulation method is proposed to additionally control the PV array current with zero switching vectors, resulting in a specific switching sequence.A direct sliding mode control method is also studied separately for the shunt and series converters, so that the zero-vector modulation method of the shunt converter can be used, with no sensitive synchronisation of the switching signals; this contrasts with the SVM method. A new dc link voltage modulation method with 12 voltage zones, instead of 6, is proposed to help overcome the limitation in the choice of shunt converter switching vectors due to the positive dc link voltage constraint.Results are obtained for the direct method on a 1 kW laboratory prototype with optimised IMC dc link connection and alternative shunt converter switching transitions to guarantee a positive dc link voltage. Current and voltage compensation capabilities are confirmed by tests in various operating conditions. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
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Real options theory applied to renewable energy generation projects planningMartinez-Cesena, Eduardo Alejandro January 2012 (has links)
The existing environmental threats and the ever increasing global dependence on electric power highlight the importance of producing power in a sustainable manner. In accordance, it is vital to attract investments in electricity generation projects based on renewable energy sources, also called renewable energy projects (REP). This poses a challenge, as REP tend to be less financially competitive than their fossil fuel based counterparts. Moreover, the power grid has to be upgraded to integrate large amounts of RESs in an efficient and economic manner. An appealing alternative to enhance the financial appealing of REP is to improve the techniques used for their assessment. These tools produce robust and economically sound assessments, but tend to undervalue REP and other projects under uncertainty, as they neglect the flexibility of the projects to be adjusted in response to uncertainty. This can be corrected by extending the tools with the aid of real options (RO) theory. RO theory can be used to extend assessment techniques to value flexibility derived from the projects, their management, and even their environment, which can be used to enhance the financial value of REP in the changing power sector. In addition, the scope of RO theory is increasing to address flexibility in the design of the projects. Therefore, the theory can drive investments in REP and motivate the design of more profitable projects. This research project seeks to analyse the potential of RO theory to increase the financial worth of different types of REP in the current and changing power sector. The novelties of this research are that it expands RO theory by addressing the flexibility within the design of the projects, the potential of RO theory to manage uncertainties that are exclusive to the projects or typical in the power sector, and other relevant areas of research interest. The research produced several RO methodologies to model the planning, operation, and design of hydropower projects, wind power projects, and solar photovoltaic projects in existing power sector environments and environments characterised by high penetration of RESs and consumers with demand response capabilities. The results demonstrate the applicability of RO theory to enhance the financial value of different types of REP under a wide range of circumstances.
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Design and Analysis of Smart Building Envelope Materials and SystemsLin, Qiliang January 2020 (has links)
As the largest consumer of electricity, the buildings sector accounts for about 76% of electricity use and 40% of all U.S. primary energy use and associated greenhouse gas (GHG) emissions. Research shows that a potential energy saving of 34.78% could be achieved by the smart buildings comparing to conventional buildings. Therefore, a smart management of building sectors becomes significantly important to achieve the optimal interior comfort with minimal energy expenditure. The ability of adaptation to the dynamic environments is considered the central aspect in smart building systems, which can be segmented into the passive adaptation and the active adaptation. The passive adaptation refers to the designs that do not change with the dynamic environment but improve the building overall performance by the integration of originally separated components, or by the application of advanced engineering materials. The active adaptation refers to the building management system (BMS) that actively responds and evolves with the changing environment, through the continuous monitoring of the surroundings via the sensor network, and the smart response through the controlling algorithms in the central controlling unit.
This Ph.D. dissertation focuses on developing materials and systems for the smart building envelope, including a photovoltaic integrated roof with passive adaptation, and self-powered window systems with active responses environment. As the skin of a building, the building envelope provides the first level resistance towards air, water, heat, light and noise, which makes it the ideal target for the passive adaptation to the environments, as well as the perfect sensing location in the building management system for the active adaptation.
This dissertation starts with a discussion of the building integrated photovoltaic thermal (BIPVT) roofing panel, including the fabrication, performance demonstration, and micromechanics-based theoretical modeling. The panel is structurally supported by a functionally graded material (FGM) panel made with high-density polyethylene as the matrix and aluminum particles as reinforcement. It prevents the heat from entering the building and directs the heat to the water tubes embedded inside the panel for the thermal energy harvesting, such that the overall energy efficiency is significantly improved. The design, fabrication and performance of the system is discussed, and an innovative non-destructive analysis method is developed to captures the authentic particle distribution of the FGM.
As the main structural component, functionally graded material is comprehensively tested and modeled in elastic, thermoelastic, elastoplastic, and thermo-elastoplastic performance, based on the equivalent inclusion based method. An ensemble average approach was used to convert the particles’ interaction in the microscope to the averaged relation in the macroscope, such that both particle to matrix influence and particle to particle pair-wise interactions are characterized. The idea of the equivalent inclusion method extends to the plastic modeling of the FGM, by formulating an ensemble average form of the matrix stress norm in the macroscale that incorporate the local disturbance of particle reinforcement in the microscale. The accuracy of the proposed algorithm is verified and validated by comparing with another theory in homogeneous composite and experiments, respectively. To the best of the author’s knowledge, no prior theoretical algorithm has been proposed for the elastoplastic modeling of functionally graded materials. Therefore, the proposed algorithm can be used as a foundation and reference for further investigation and industry prediction of graded composites.
Based on the theoretical modeling of the mechanical properties, a high order plate theory is also proposed in this dissertation to study for the thermo-mechanical performance of the FGM panel, to provide structural design guideline for the BIPVT panels. The shearing and bending behaviors are decomposed, solved independently, and combined to formulate the final solution. The shear strain components are assumed to follow a parabolic variation across the thickness, while the bending components follow the solution from classical plate theory. Closed-form solutions for the circular panel under different loadings are provided, with verification by comparing to other models and validation to experiments.
Two smart window systems are proposed and demonstrated in this dissertation to actively monitor the building environment with active responses, and energy harvesting techniques are investigated to harvest energy from ambient environment the eternal power supply to the system. The thermoelectric powered wireless sensor network (TPWSN) platform is first demonstrated and discussed, where the energy is harvested from the temperature difference across the window frame. The TPWSN sits completely inside the window/façade frame with no compromise of the outlook and continuously monitors the building environment for the optimal control of the building energy consumption and indoor comfort. The energy harvesting technique grants eternal battery lifetime and significantly simplifies the installation and maintenance of the system with considerable saving of time and cost. In addition, the platform provides energy to various types of sensors for different kinds of sensing needs and store the data to the Google cloud for permanent storage and advanced analytics.
The thermoelectric powered system works well for the sensors and microcontrollers but fails to provide enough power to the actuators. A novel sun-powered smart window blinds (SPSWB) system is designed, prototyped, and tested in this dissertation with solar energy harvesting on window blinds which provides enough power for the actuators. The thin-film photovoltaic cells are attached on one side of slats for energy harvesting and a PVdF-HFP coating is attached on the other side for the passive cooling. The voltage regulation and battery management systems are designed and tested, where a stable 55% energy efficiency from the PV into the battery has been achieved. The automatic control of the window blinds is accomplished with the help of sensors and a microcontroller. The energy equilibrium analysis is proposed and demonstrated with the local solar data to incorporate the influence of local weather conditions and solar zenith angle, from which we demonstrated that much more power than needed can be harvested. The abundant energy harvested validates the feasibility and the robustness of the system and proves its wide application potentials to various sensors and applications.
In conclusion, both passive and active adaptations to the environment are investigated to build up the next generation of smart building envelope systems. The building integrated photovoltaic thermal roof is designed, fabricated, tested, and modeled in detail, which provides structural support to the external loads and improves the energy efficiency of buildings. The smart window/façade systems serve as a platform for various sensors and actuators via the energy harvesting from the ambient environment, and could significantly improve the energy expenditure with minimal impact of internal comfort.
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Potential för solcellsanläggningar : SSAB industriområde, Borlänge / Potential of PV-generated electricity for SSAB in BorlängeBjurell, Lovisa, Svensson, Joel January 2022 (has links)
SSAB har som mål till år 2026 att producera fossilfritt stål och vara helt fossilfria vid år 2030. Ett led i att lyckas med detta är att generera egen förnybar elektricitet. I detta arbete utreds på uppdrag av SSAB potentialen för att generera förnybar energi i form av solel på deras industriområde i Borlänge. Denna studie ger även förslag på vilken solcellsteknik som kan utnyttjas, samt hur effekten från solcellsanläggningarna påverkar SSAB:s två största transformatorer. Baslasten för dessa transformatorer kan till stor del uppnås av solcellsanläggningarna mellan april – augusti. De avgränsningar som gjorts syftar till att utreda potentialen av de största ytorna på mark och byggnader inom SSAB:s industriområde. Simuleringar har genomförts med programvaran PVsyst för ett flertal solcellsanläggningar. Arbetet lyfter aspekter om hur solcellsanläggningar fungerar, planeras och påverkas av exempelvis solinstrålning, väder och orientering. Resultatet visar att på de ytor som valdes ut kan en maximal effekt på 28 MWp installeras. Övervägande del av den totala effekten kan installeras på de tillgängliga markytorna, vilket motsvarar ca 70 % av den simulerade installationen. Då de tillgängliga ytorna är riktade åt olika håll kommer de olika föreslagna installationerna att ha sin maximala uteffekt vid olika tillfällen, varför den maximala uteffekten från samtliga anläggningar aldrig överskrider 22 MW. Den totala mängd el som kan genereras från samtliga installationer är 23,7 GWh / år. Denna energimängd motsvarar ca 6 % av SSAB i Borlänges totala elanvändning. Med monokristallina solceller uppgår en kostnad för alla installationerna om 164 miljoner kronor ± 20 %. / SSAB's goal by year 2026 is to produce fossil-free steel and be completely fossil-free by 2030. One step to succeed in this is to generate their own renewable energy. In this work, the authors investigated the potential for generating renewable energy in the form of solar electricity at SSAB’s industrial area in Borlänge. This study also provides suggestions on which solar cell technology can be utilized, as well as how the power from the photovoltaic plants affects SSAB's two largest transformers. The base load of these transformers can mostly be achieved by the photovoltaic plants between April – August. The boundaries made aim to investigate the potential of the largest areas in the form of land and on buildings of the industrial area. Simulations have been carried out with the software PVsyst for several photovoltaic systems. This work highlights aspects of how photovoltaic systems work, how they are planned and affected by, for example, solar radiation, weather and orientation. The simulated photovoltaic systems have different conditions based on the different aspects, where each one has their pros and cons. The result shows that on the surfaces that were selected, a maximum power of 28 MWp can be installed. Most of the total power can be installed on the available land surfaces, which corresponds to about 70 % of the simulated installation. As the available areas are directed in different directions, the proposed installations will have their maximum output at different times, so the maximum output from all plants never exceeds 22 MW. The total amount of electricity that can be generated from all installations is 23.7 GWh / year. This amount of energy corresponds to about 6% of SSAB in Borlänge's total electricity use. With monocrystalline solar cells, a cost for all installations amounts to SEK 164 million ± 20%.
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