890 resultados para Generation Dispatch, Power Generation, Power System Simulation, Wind Energy Integration
Resumo:
In modern society, the body health is a very important issue to everyone. With the development of the science and technology, the new and developed body health monitoring device and technology will play the key role in the daily medical activities. This paper focus on making progress in the design of the wearable vital sign system. A vital sign monitoring system has been proposed and designed. The whole detection system is composed of signal collecting subsystem, signal processing subsystem, short-range wireless communication subsystem and user interface subsystem. The signal collecting subsystem is composed of light source and photo diode, after emiting light of two different wavelength, the photo diode collects the light signal reflected by human body tissue. The signal processing subsystem is based on the analog front end AFE4490 and peripheral circuits, the collected analog signal would be filtered and converted into digital signal in this stage. After a series of processing, the signal would be transmitted to the short-range wireless communication subsystem through SPI, this subsystem is mainly based on Bluetooth 4.0 protocol and ultra-low power System on Chip(SoC) nRF51822. Finally, the signal would be transmitted to the user end. After proposing and building the system, this paper focus on the research of the key component in the system, that is, the photo detector. Based on the study of the perovskite materials, a low temperature processed photo detector has been proposed, designed and researched. The device is made up of light absorbing layer, electron transporting and hole blocking layer, hole transporting and electron blocking layer, conductive substrate layer and metal electrode layer. The light absorbing layer is the important part of whole device, and it is fabricated by perovskite materials. After accepting the light, the electron-hole pair would be produced in this layer, and due to the energy level difference, the electron and hole produced would be transmitted to metal electrode and conductive substrate electrode through electron transporting layer and hole transporting layer respectively. In this way the response current would be produced. Based on this structure, the specific fabrication procedure including substrate cleaning; PEDOT:PSS layer preparation; pervoskite layer preparation; PCBM layer preparation; C60, BCP, and Ag electrode layer preparation. After the device fabrication, a series of morphological characterization and performance testing has been done. The testing procedure including film-forming quality inspection, response current and light wavelength analysis, linearity and response time and other optical and electrical properties testing. The testing result shows that the membrane has been fabricated uniformly; the device can produce obvious response current to the incident light with the wavelength from 350nm to 800nm, and the response current could be changed along with the light wavelength. When the light wavelength keeps constant, there exists a good linear relationship between the intensity of the response current and the power of the incident light, based on which the device could be used as the photo detector to collect the light information. During the changing period of the light signal, the response time of the device is several microseconds, which is acceptable working as a photo detector in our system. The testing results show that the device has good electronic and optical properties, and the fabrication procedure is also repeatable, the properties of the devices has good uniformity, which illustrates the fabrication method and procedure could be used to build the photo detector in our wearable system. Based on a series of testing results, the paper has drawn the conclusion that the photo detector fabricated could be integrated on the flexible substrate and is also suitable for the monitoring system proposed, thus made some progress on the research of the wearable monitoring system and device. Finally, some future prospect in system design aspect and device design and fabrication aspect are proposed.
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Los anuncios de impacto por cambio climático han llevado a los países a crear estrategias de mitigación y adaptación, dentro de las cuales se considera la promoción de generación de electricidad a través de fuentes renovables no convencionales -- El avance logrado ha incentivado a los usuarios del servicio de energía eléctrica a invertir en plantas de generación, eliminando la necesidad parcial de utilizar las redes de transmisión y distribución del sistema eléctrico, de tal forma que las redes eléctricas presentan una holgura gradual en cuanto a la energía que se transporta a través de ellas -- Este artículo presenta un análisis del impacto sobre los ingresos operacionales de una empresa distribuidora de energía por efecto de la entrada de soluciones de energía solar fotovoltaica en el segmento residencial de su área de influencia, encontrando que se generarían diferentes escalas de afectación, con valores de hasta el 3%
Resumo:
Energy indicators are tools to support decision-making on energy. The growing debate on sustainable development, contributed to the energy indicators began to incorporate, besides the traditional economic, social and environmental information. Therefore, taking sustainable development into account, it is important to know contributions and limitations of these tools. The overall goal of this study is to analyze the contributions and limitations of the energy indicators as assets to support sustainable development.This study can be classified as descriptive because it relies on bibliographical and documental material. As a result of documental analysis, 55 energy indicators for sustainable development (EISD) were selected. The selection took place by identification of those indicators through the institutions International Atomic Energy Agency (IAEA), Helio International and World Energy Council (WEC), among 19 institutions involved in research on energy identified in the survey. The study stresses that most of the selected indicators focuses on the economic dimension, 19 EISDs (34.54%), followed by 10 EISDs (18.18%) focused on the environmental dimension, 9 EISDs (16.36%) focused on the social issues, 7 EISDs (12.45%) are classified as resilience, 4 EISDs (7.27%) is about governance, 3 EISDs (5.45%) focused on vulnerability and 3 EISDs (5.45%) is about policy. Despite the inclusion of indicators associated with other dimensions than economy, information provided by those indicators emerges as their own limitation. Because, recently, indicators’ information were used to promote sustainable development as well as the opposite. Additionally, the study identified EISDs whose components were not specified. They may enable generation of information far from the real scenario, if components dissociated EISD would be taking into consideration or even the non-consideration of relevant components. Despite limitations, EISDs assisting decision-makers contributes to the pursuit of sustainable development. But they may be improved through information about environmental issues, such as emission of atmospheric pollutants, soil and water, resulting from energy sources, helps identifying which sources are more or less harmful for sustainable development. However, difficulty in collecting data, identifying the components for calculation of each indicator and even interpretation of this, as analyzed, may not only fail to contribute to sustainable development, as can delay taking corrective or preventive decisions.
Resumo:
Offshore wind turbines operate in a complex unsteady flow environment which causes unsteady aerodynamic loads. The unsteady flow environment is characterized by a high degree of uncertainty. In addition, geometry variations and material imperfections also cause uncertainties in the design process. Probabilistic design methods consider these uncertainties in order to reach acceptable reliability and safety levels for offshore wind turbines. Variations of the rotor blade geometry influence the aerodynamic loads which also affect the reliability of other wind turbine components. Therefore, the present paper is dealing with geometric uncertainties of the rotor blades. These can arise from manufacturing tolerances and operational wear of the blades. First, the effect of geometry variations of wind turbine airfoils on the lift and drag coefficients are investigated using a Latin hypercube sampling. Then, the resulting effects on the performance and the blade loads of an offshore wind turbine are analyzed. The variations of the airfoil geometry lead to a significant scatter of the lift and drag coefficients which also affects the damage-equivalent flapwise bending moments. In contrast to that, the effects on the power and the annual energy production are almost negligible with regard to the assumptions made.
Resumo:
Wind energy is one of the most promising and fast growing sector of energy production. Wind is ecologically friendly and relatively cheap energy resource available for development in practically all corners of the world (where only the wind blows). Today wind power gained broad development in the Scandinavian countries. Three important challenges concerning sustainable development, i.e. energy security, climate change and energy access make a compelling case for large-scale utilization of wind energy. In Finland, according to the climate and energy strategy, accepted in 2008, the total consumption of electricity generated by means of wind farms by 2020, should reach 6 - 7% of total consumption in the country [1]. The main challenges associated with wind energy production are harsh operational conditions that often accompany the turbine operation in the climatic conditions of the north and poor accessibility for maintenance and service. One of the major problems that require a solution is the icing of turbine structures. Icing reduces the performance of wind turbines, which in the conditions of a long cold period, can significantly affect the reliability of power supply. In order to predict and control power performance, the process of ice accretion has to be carefully tracked. There are two ways to detect icing – directly or indirectly. The first way applies to the special ice detection instruments. The second one is using indirect characteristics of turbine performance. One of such indirect methods for ice detection and power loss estimation has been proposed and used in this paper. The results were compared to the results directly gained from the ice sensors. The data used was measured in Muukko wind farm, southeast Finland during a project 'Wind power in cold climate and complex terrain'. The project was carried out in 9/2013 - 8/2015 with the partners Lappeenranta university of technology, Alstom renovables España S.L., TuuliMuukko, and TuuliSaimaa.
Resumo:
Tese de Doutoramento, Gestão da Inovação e do Território, Faculdade de Economia, Universidade do Algarve, 2016
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This thesis presents a load sharing method applied in a distributed micro grid system. The goal of this method is to balance the state-of-charge (SoC) of each parallel connected battery and make it possible to detect the average SoC of the system by measuring bus voltage for all connected modules. In this method the reference voltage for each battery converter is adjusted by adding a proportional SoC factor. Under such setting the battery with a higher SoC will output more power, whereas the one with lower SoC gives out less. Therefore the higher SoC battery will use its energy faster than the lower ones, and eventually the SoC and output power of each battery will converge. And because the reference voltage is related to SoC status, the information of the average SoC in this system could be shared for all modules by measuring bus voltage. The SoC balancing speed is related to the SoC droop factors. This SoC-based load sharing control system is analyzed in feasibility and stability. Simulations in MATLAB/Simulink are presented, which indicate that this control scheme could balance the battery SoCs as predicted. The observation of SoC sharing through bus voltage was validated in both software simulation and hardware experiments. It could be of use to non-communicated distributed power system in load shedding and power planning.
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In this paper, the IEEE 14 bus test system is used in order to perform adequacy assessment of a transmission system when large scale integration of electric vehicles is considered at distribution levels. In this framework, the symmetric/constr ained fuzzy power flow (SFPF/CFPF) was proposed. The SFPF/CFPF models are suitable to quantify the adequacy of transmission network to satisfy “reasonable demands for the transmission of electricity” as defined, for instance, in the European Directive 2009/72/EC. In this framework, electric vehicles of different types will be treated as fuzzy loads configuring part of the “reasonable demands”. With this study, it is also intended to show how to evaluate the amount of EVs that can be safely accommodated to the grid meeting a certain adequacy level.
Resumo:
El presente trabajo de Grado tiene como propósito examinar la incidencia de las sancionesinternacionales en el marco del régimen de no proliferación nuclear en el caso de Irán durante el periodo 2006-2015, teniendo en cuenta factores históricos de años anteriores. Se analiza y explica cómo las sanciones internacionales pueden ser una medida persuasiva por violar ciertos artículos del Tratado de no Proliferación Nuclear. Finalmente identifica y analiza los tipos de sanciones económicas, financieras y comerciales que los Estados y el Consejo de Seguridad de las Naciones Unidas le han impuesto a Irán, así como la manera en que estas han incidido en la esfera política iraní y mundial.
Resumo:
La presente investigación pretendió incorporar el uso intensivo de TIC en los procedimientos establecidos y necesarios en los procesos de generación, distribución y control de la energía, lo que se expresa en un manual para el sistema de gestión humana de la organización analizada. La investigación partió de un levantamiento de un estado del arte, continuó con la realización de un análisis de actitudes y aptitudes de los colaboradores, basado en propuestas teóricas y mejores prácticas existentes del medio, y, por último, concluyó con un manual de gestión humana en el que se indican las competencias en los diferentes perfiles de la organización para el uso de TIC y su aplicación, con el propósito de alinearse con las perspectivas y objetivos de la organización analizada al tener como base la perdurabilidad y la competitividad de la misma.
Resumo:
This paper focuses on technology state of the art for the charge/discharge of electric energy storage supported by vanadium redox flow battery linked to the electric grid. Properties of vanadium, the main configuration and the reaction of charge/discharge of a vanadium redox flow battery are addressed. The vanadium redox flow battery has the highest cell voltage among the other redox flow battery, implying higher power and energy density which favours application at power plants. This electric energy storage is viewed as a promising contribution to be integrated in power system due to a reasonably bulky size and to successful applications currently allowing storage of energy at power plants or at electrical grids. For instances, allowing storage of energy as an economic improvement providing spin reserve to avoid penalty for imbalances between the energy delivered and energy contracted at closing of electricity market or as an economic improvement to diminish the cost of electricity usage of a consumer. The vanadium redox flow battery has the advantages of scalability customized to meet requirements for power and energy capacity and of excellent combination of energy efficiency, capital cost and life cycle costs compared with other technology.
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The behavior of stability regions of nonlinear autonomous dynamical systems subjected to parameter variation is studied in this paper. In particular, the behavior of stability regions and stability boundaries when the system undergoes a type-zero sadle-node bifurcation on the stability boundary is investigated in this paper. It is shown that the stability regions suffer drastic changes with parameter variation if type-zero saddle-node bifurcations occur on the stability boundary. A complete characterization of these changes in the neighborhood of a type-zero saddle-node bifurcation value is presented in this paper. Copyright (C) 2010 John Wiley & Sons, Ltd.
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This paper aims to find relations between the socioeconomic characteristics, activity participation, land use patterns and travel behavior of the residents in the Sao Paulo Metropolitan Area (SPMA) by using Exploratory Multivariate Data Analysis (EMDA) techniques. The variables influencing travel pattern choices are investigated using: (a) Cluster Analysis (CA), grouping and characterizing the Traffic Zones (17), proposing the independent variable called Origin Cluster and, (b) Decision Tree (DT) to find a priori unknown relations among socioeconomic characteristics, land use attributes of the origin TZ and destination choices. The analysis was based on the origin-destination home-interview survey carried out in SPMA in 1997. The DT application revealed the variables of greatest influence on the travel pattern choice. The most important independent variable considered by DT is car ownership, followed by the Use of Transportation ""credits"" for Transit tariff, and, finally, activity participation variables and Origin Cluster. With these results, it was possible to analyze the influence of a family income, car ownership, position of the individual in the family, use of transportation ""credits"" for transit tariff (mainly for travel mode sequence choice), activities participation (activity sequence choice) and Origin Cluster (destination/travel distance choice). (c) 2010 Elsevier Ltd. All rights reserved.
Resumo:
This letter presents an extension of an existing ground distance relay algorithm to include phase distance relays. The algorithm uses a fault resistance estimation process in the phase domain, improving efficiency in the distance protection process. The results show that the algorithm is suitable for online applications, and that it has an independent performance from the fault resistance magnitude, the fault location, and the line asymmetry.