• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 3
  • 3
  • 1
  • 1
  • Tagged with
  • 19
  • 19
  • 9
  • 8
  • 8
  • 7
  • 7
  • 6
  • 6
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Design optimization of utility-scale PV power plant

Farzaneh Kaloorazi, Meisam, Ghaneei Yazdi, Marzieh January 2021 (has links)
Solar energy market has been rapidly growing in Sweden over the past few years. Älvdalen municipality in central Sweden is investigating the possibility of installing a utility-scale solar power plant. In the present work, we investigate technical design and economic viability of a utility-scale solar power plant in Älvdalen. Several photovoltaics (PV) designs on a 6.6-hectar land are modeled and analyzed. The installation capacity depends on design parameters, such as inter-row spacing distance and orientation.PVsyst simulation tool is used to model several PV system configurations, consisting of both mono- and bifacial PV modules. An extensive sensitivity analysis is performed to get a deep understanding of different design parameters and their effects on performance and production yield of the plant.For PV systems consisting of monofacial PV panels, a set of parameters is investigated, namely, tilt angle of PV arrays, space between rows of the plant. It is observed that an optimized design requires a careful consideration of the two parameters, since they considerably affect the amount of self-shading (shading of PV rows on each other).The optimum design generates more than 5000 MWh electricity annually.Bifacial configurations are designed in two forms: tilted (south or south-east facing) and vertical (east-west oriented). Tiled bifacial systems are basically similar to the monofacial ones. A comparison between the two systems shows that the bifacial gain is between 3 % to 10 %, depending on the tilt angle, inter-row spacing, and PV array height above the ground. Electricity generation per surface area of the vertical east-west bifacial configuration is significantly lower compared to the others and therefore, it is only economically viable together with other land applications, such as agricultural usage.Economical evaluation indicates that for the optimum design the levelized cost of energy (LCOE) is 0.67 SEK/MWh and 0.72 SEK/MWh for monofacial and bifacial system, respectively. Such financial figures are subject to change, depending on the design and financial parameters.
12

Estudo e modelagem da arquitetura modular de uma usina solar fotovoltaica arrefecida com protótipo de verificação. / Study and modeling of modular architecture of a solar photovoltaic power plant cooled with verification prototype.

Silva, Vinícius Oliveira da 30 November 2015 (has links)
O objetivo deste trabalho é modelar a arquitetura de uma usina solar fotovoltaica arrefecida intitulada UFVa, utilizando um protótipo de verificação. A metodologia se baseia na medição, verificação e análise dos dados de temperatura e produção de energia elétrica dos strings de teste (arrefecido) e comparação (não arrefecido), estudo do comportamento da alimentação de água do sistema de arrefecimento e o impacto das condições climáticas na operação do protótipo de UFVa. Por meio das análises dos dados constatou-se que, para o período entre as 09h00min e as 17h30min, os módulos PV do string de teste sempre operam com temperaturas inferiores aos módulos PV do string de comparação. Durante o período de testes, no qual a temperatura dos módulos PV do string de comparação operou acima de 55,0°C, as temperaturas médias e máximas registradas nos módulos PV do string de teste foram inferiores a 37,0 °C, operando sempre abaixo da temperatura nominal de operação da célula (NOCT). A produção de energia elétrica no string de teste superou a do string de comparação em 3,0kWh/dia. Portanto, o sistema de arrefecimento reduz a temperatura de operação dos módulos PV, principalmente no período de máxima geração elétrica, que corresponde ao período das 11h00min às 15h00min, proporcionando ganhos médios de rendimento de 5,9% na produção de energia, 10,3% na potência e 5,4% no FC. / In this work we use a verification prototype to model the architecture of a solar photovoltaic power plant equipped with a cooling system. The power plant we model is called UFVa. The methodology is based on the measurement, verification, and data analysis of temperature, electricity generation, test strings (cooled) and comparison strings (not cooled), along with a study of the water feeding behavior of the cooling system, and the impact of climatic conditions in the UFVa prototype operation. By analyzing the data we observed that, for the period between 09:00am and 5:30pm, the PV modules of the test string operate at temperatures below those of the PV modules of the comparison string. During the tests, in which the temperature of the PV modules of the comparison string operated above 55.0°C, the average and the maximum temperatures recorded in the PV modules of the testing string lied below 37.0°C, operating below the NOCT. Regarding the generation of electricity, the test string generated 3.0 kWh/day more than the comparison string. Hence, the cooling system decreases the operating temperature of the PV modules, particularly during the maximum power generation period which is from 11am to 3pm. This leads to efficiency average gains of up to 5.9% in the generation of electricity, 10.3% in the power, and 5.3% in the PR and PF.
13

Inversor flyback a quatro transistores controlado por um dispositivo FPGA para obter MPPT em sistemas fotovoltaicos

Marques, Fernando Nunes 04 November 2008 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Electrical energy generation with photovoltaic cells is being more utilized. Not only on large scale systems, but also in small ones connected to the grid. Parallel operating with the great generators from power companies, in a non-centralized way of operation, supplying low power, installed in houses, commerce establishments, industry, with the goal to minimize the loss in transmission, for being installed at the same consumption place. This work presents a FPGA device controller of a four transistor flyback inverter for maximum power point in photovoltaic systems. Despite this system has low power it contributes to search simple and low cost alternatives for generating of electrical power in a decentralized manner, which does not use battery banks connected parallel to network of energy near to consumers. / Geração de energia elétrica a partir de painéis fotovoltaicos vem sendo cada vez mais utilizada, não somente em sistemas fotovoltaicos de grande porte, como também em pequenos sistemas conectados a rede CA. Interligada paralelamente aos grandes geradores da concessionária de energia de forma descentralizada em sistemas de pequeno porte e baixas potências, instalados em residências, estabelecimentos comerciais, indústria, com o objetivo de minimizar perdas por transmissão por estarem instalados nos próprios locais. Este trabalho apresenta um controle num dispositivo FPGA de um inversor flyback a quatro transistores para máxima potência em sistemas fotovoltaicos. Apesar da baixa potência este contribui para a busca de alternativas simples e de baixo custo para geração de energia elétrica de forma descentralizada, não utilizando bancos de bateria conectados paralelamente a rede de energia próxima aos consumidores. / Mestre em Ciências
14

Estudo e modelagem da arquitetura modular de uma usina solar fotovoltaica arrefecida com protótipo de verificação. / Study and modeling of modular architecture of a solar photovoltaic power plant cooled with verification prototype.

Vinícius Oliveira da Silva 30 November 2015 (has links)
O objetivo deste trabalho é modelar a arquitetura de uma usina solar fotovoltaica arrefecida intitulada UFVa, utilizando um protótipo de verificação. A metodologia se baseia na medição, verificação e análise dos dados de temperatura e produção de energia elétrica dos strings de teste (arrefecido) e comparação (não arrefecido), estudo do comportamento da alimentação de água do sistema de arrefecimento e o impacto das condições climáticas na operação do protótipo de UFVa. Por meio das análises dos dados constatou-se que, para o período entre as 09h00min e as 17h30min, os módulos PV do string de teste sempre operam com temperaturas inferiores aos módulos PV do string de comparação. Durante o período de testes, no qual a temperatura dos módulos PV do string de comparação operou acima de 55,0°C, as temperaturas médias e máximas registradas nos módulos PV do string de teste foram inferiores a 37,0 °C, operando sempre abaixo da temperatura nominal de operação da célula (NOCT). A produção de energia elétrica no string de teste superou a do string de comparação em 3,0kWh/dia. Portanto, o sistema de arrefecimento reduz a temperatura de operação dos módulos PV, principalmente no período de máxima geração elétrica, que corresponde ao período das 11h00min às 15h00min, proporcionando ganhos médios de rendimento de 5,9% na produção de energia, 10,3% na potência e 5,4% no FC. / In this work we use a verification prototype to model the architecture of a solar photovoltaic power plant equipped with a cooling system. The power plant we model is called UFVa. The methodology is based on the measurement, verification, and data analysis of temperature, electricity generation, test strings (cooled) and comparison strings (not cooled), along with a study of the water feeding behavior of the cooling system, and the impact of climatic conditions in the UFVa prototype operation. By analyzing the data we observed that, for the period between 09:00am and 5:30pm, the PV modules of the test string operate at temperatures below those of the PV modules of the comparison string. During the tests, in which the temperature of the PV modules of the comparison string operated above 55.0°C, the average and the maximum temperatures recorded in the PV modules of the testing string lied below 37.0°C, operating below the NOCT. Regarding the generation of electricity, the test string generated 3.0 kWh/day more than the comparison string. Hence, the cooling system decreases the operating temperature of the PV modules, particularly during the maximum power generation period which is from 11am to 3pm. This leads to efficiency average gains of up to 5.9% in the generation of electricity, 10.3% in the power, and 5.3% in the PR and PF.
15

Podnikatelský plán - Fotovoltaická elektrárna v Rumunsku / Photovoltaic power plant in Romania

Brothánek, Ondřej January 2012 (has links)
Renewable energy resources, especially photovoltaics, have experienced enormous boom all over the world in the past few years. It was completely the same in Czech Republic where you would not find anybody without his own opinion regarding PV business. Installation of PV power plants has become very attractive business, with very significant role in 2011 in Czech Republic. At this time, this solar boom has found its "home" in other European countries, particularly in Eastern Europe. The post of the new Eastern Europe's "powerhouse" can defend even Romania, that's the cause I have chosen this country as the subject of this thesis. The aim of this thesis is to create a business plan for PV power plant and evaluate the investment opportunity of its installation in Romania. And then by means of a sensitivity analysis find out the impact of external factors that can significantly affect the profitability of the project.
16

Powering the Future : Electric Vehicle Charging Needs and Infrastructure in Uppsala’s Southeast District

Lundin, Hanna, af Ekenstam, Sofia, Stensvad, Louise, Sterner, Anna January 2024 (has links)
Uppsala Municipality is planning to build the southeast city district (SÖS), aiming to achieve climate neutrality by 2030 and climate positivity by 2050. In this thesis, the integration of electric vehicles (EVs) and charging infrastructure was investigated. It also examined the power demand, and the potential of photovoltaic (PV) production in combination with a battery storage system in SÖS, and its ability to reduce power peaks. The study was delimited to only incorporating charging demand in mobility houses, not from the private parking spots, as well as excluding alternative fossil-free vehicle options. Utilizing a stochastic model and data from Copenhagen and Stockholm, using trends for car pools and EV ratio, two scenarios were designed to forecast the spread of EVs and their impact on the power grid in SÖS by 2050. Since SÖS consists of both residential housing and workplaces, three different simulations were created to take their differences in mobility pattern into account. The two scenarios generated a different number of EVs, which resulted in a varied amount of charging points. Furthermore, the difference in EVs and mobility patterns showed different values of power demands and power peaks. PV panels combined with a battery storage system were able to both reduce the daily power demand, as well as the power peaks. For the sensitivity analysis, different sizes of the battery storage were examined. Finally, this report presents guidance for how to manage the challenges with an increased power demand from the more extensive use of EVs.
17

Development of an efficient nano-fluid cooling/preheating system for PV-RO water desalination pilot plant

Shalaby, S.M., Elfakharany, M.K., Mujtaba, Iqbal, Moharram, B.M., Abosheiasha, H.F. 04 July 2022 (has links)
Yes / In order to improve the performance of the reverse osmosis (RO) desalination plant powered by photovoltaic (PV), two cooling systems were proposed in this study to cool the PV and preheating the RO feed water as well. In the cooling design (1), the cooling fluid flows in direct contact with the back surface of the PV through channels of half circular cross-sections. While in the design (2), it flows through channels of squar cross-sections fixed on the PV back surface. Two nano-fluids were also tested as cooling fluid: H2O/CuO and H2O/Al2O3, in addition to distilled water for the purpose of comparison. The effect of changing the weight concentration of the nano-fluid (0.05, 0.1, and 0.15%) on the PV performance was also investigated. The results showed that the PV integrated with the cooling design (1) achieves better performance compared to design (2) at all studied cooling fluids. The improvements in the electric efficiency of the PV integrated with design (1) reached 39.5, 34.8 and 27.3 % when CuO and Al2O3 nano-fluids and distilled water were used as cooling fluid, respectively, compared to the uncooled PV. Based on the obtained experimental results, the PV integrated with design (1) was selected to power the RO with H2O/CuO nano-fluid of weight concentration 0.15% and flow rate 0.15 kg/s being used as the coolant. The RO powered by the improved PV was tested at different salinities of brackish water when the preheating technique was implemented. The results showed that the proposed PV-RO desalination system produces 366 l/day when brackish water of salinity 3000 ppm was used.
18

Návrh technického provedení FVE včetně systému řízení pro komerční objekt v souladu s platnými pravidly pro program ÚSPORY ENERGIE - FVE / Photovoltaic System Proposal for Commercial Building in Accordance with Applicable Rules for Energy Savings Program

Zeman, Daniel January 2018 (has links)
Main purpose of the thesis is to create proposal of the photovoltaic hybrid system for commercial building in accordance with applicable rules for energy savings program. The introductory part of the thesis describes the rules regarding the photovoltaic system parts. The next part of the thesis describes the available technical solution for realization of the photovoltaic system design and the possibilities of electric energy accumulation in these systems and how to deal with power overflows using the power flow controller and what is the negative impacts on the distribution network when switching the connected load. In the next part the design of the PV system is carried out according to the valid assumptions described in the theoretical part of the thesis. Verification of power flow controller and measurement results in UEEN laboratories. The last part of the thesis is an evaluation of the economic part of the proposed system.
19

Implementation of Intelligent Maximum Power Point Tracking Control for Renewable Power Generation Systems

Chang, Chih-Kai 19 June 2012 (has links)
This thesis discusses the modeling of a micro-grid with photovoltaic (PV)-wind-fuel cell (FC) hybrid energy system and its operations. The system consists of the PV power, wind power, FC power, static var compensator (SVC) and an intelligent power controller. Wind and PV are primary power sources of the system, and an FC-electrolyzer combination is used as a backup and a long-term storage system. A simulation model for the micro-grid control of hybrid energy system has been developed using MATLAB/Simulink. A SVC was used to supply reactive power and regulate the voltage of the hybrid system. To achieve a fast and stable response for the real power control, the intelligent controller consists of a Radial Basis Function Network-Sliding Mode Control (RBFNSM) and a General Regression Neural Network (GRNN) for maximum power point tracking (MPPT). The pitch angle of wind turbine is controlled by RBFNSM, and the PV system uses GRNN, where the output signal is used to control the DC/DC boost converters to achieve the MPPT.

Page generated in 0.0406 seconds