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  • 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.
81

Energy management in electric systems fed by fuel cell stacks / Gestion d'energie dans des systemes electriques de puissance alimentes par piles a combustible

Sanchez, Antonio 09 March 2011 (has links)
La croissance des unités de distribution des ressources énergétiques ainsi que l'intégration des nouvelles technologies dans la production et le stockage d'énergie, ont imposé un contrôle nouveau et de nouvelles stratégies opérationnelles. Grâce à sa capacité de stockage et étant considérée comme une énergie propre; la pile à combustible (Pac) est l'une des technologies les plus prometteuse en tant que source d'énergie stationnaire dans les réseaux micro et aussi dans les applications de transport. Par conséquent, deux sujets principaux sont abordés dans cet ouvrage, la conception et l'installation d'un banc d'essai complet instrumenté a membrane échangeuse de polymère (PEM) Pac et de conception et l'essai expérimental d'une nouvelle stratégie de contrôle dynamique d'échange de l'énergie pour les systèmes multi - source et multi - charge. Pour définir le test instruments banc exigences, un examen complet de modèle dynamique est donné dans la première partie. Dans la prochaine section seront inclues, les renseignements concernant la configuration de la conception et la mise en œuvre de banc d'essai de Pac, i.e., critères de spécification des instruments, acquisition, et affichage des données du système. Des résultats expérimentaux sont réalisés afin de démontrer les potentialités de l'installation. Dans le chapitre suivant, une nouvelle stratégie de contrôle dynamique de l'énergie d'échange (DSER) sera introduite et testée par simulation et expérimentalement dans un système à deux ports. Afin d'établir une comparaison et d'intégrer la DSER dans une application Pac, un système à trois ports - y compris un modèle statique de Pac - et deux différentes approches de contrôle, seront testés par simulation dans le cinquième chapitre. La thèse s’achèvera par quelques conclusions et quelques thèmes de recherche potentiels générés à partir de ce travail. / The growth of distributed energy resources together with the incorporation of new technologies in the generation and storage of energy are imposing new control and operational strategies. Due to its storage capability and that it is considered to be clean energy; fuel cell (FC) is one of the most promissory technologies as a stationary energy source in micro grids and also in transportation applications. Therefore, two main issues are addressed in this work; the conception, design, and setup of a fully instrumented test bench for proton exchange membrane (PEM) FC stacks and the design and experimental test of a new dynamic energy-exchange control strategy for multi source and multi load systems. To define the test bench instrument requirements, in the first part a complete dynamic model review is given. In the next section, relevant information regarding the setup of the FC test bench design and implementation is included, i.e., specification criteria of the instruments and acquisition and data display system. Some experimental results are performed in order to demonstrate the potentialities of the setup. In the following chapter, a new dynamic energy exchange control strategy (DSER) is introduced and tested in a two port system via simulation and experimentation. In order to establish a comparison and integrate the DSER in a FC application, in the fifth chapter a three port system – including a static model of FC – and two different control approaches, are tested via simulation. The thesis is closed with some concluding remarks and some potential research topics generated from this work.
82

Adaptive energy management mechanisms for cluster based routing wireless sensor networks

Eshaftri, Mohamed January 2017 (has links)
Wireless Sensor Network (WSN) technology has been one of the major avenues of Internet of Things (IoT) due to their potential role in digitising smart physical environments. WSNs are typically composed of a vast number of low-power, low–cost and multifunctional sensor nodes within an area that automatically cooperate to complete the application task. This emerging technology has already contributed to the advancement of a broad range of applications. Nevertheless, the development of WSNs is a challenging issue due to significant concerns, which need to be resolved to take full benefit of this remarkable technology. One of the main challenges of WSNs is how to reduce the energy consumption of a single node, in order to extend the network lifetime and improves the quality of service. For that reason, a newly design energy efficient communication protocol is required to tackle the issue. The clustering protocols designed for communication are alleged to be one of the most efficient solutions that can contribute to network scalability and energy consumption in WSNs. While different clustering protocols have been proposed to tackle the aforementioned issue, those solutions are either not scalable or do not provide the mechanisms to avoid a heavy loaded area. This thesis presents new adaptive energy management mechanisms, through which the limited critical energy source can be wisely managed so that the WSN application can achieve its intended design goals. Three protocols are introduced to manage the energy use. The first protocol presents an intra-cluster CH rotation approach that reduces the need for the execution of a periodical clustering process. The second protocol relates to load balancing in terms of the intra and inter-cluster communication patterns of clusters of unequal sizes. This proposed approach involves computing a threshold value that, when reached, triggers overall network re-clustering, with the condition that the network will be reconfigured into unequal cluster size. The third protocol proposes new performance factors in relation to CH selection. Based on these factors, the aggregated weight of each node is calculated, and the most suitable CH is selected. A comparison with existing communication protocols reveals that the proposed approaches balance effectively the energy consumption among all sensor nodes and significantly increase the network lifetime.
83

Enhancing environmental sustainability of healthcare facilities : a system dynamics analysis approach

Shehab, Salman Ali Salman January 2017 (has links)
Due to the limited studies related to healthcare services future expanding demand, required resources and utilities, and related environmental and economic challenges; this research is carried out to complement other researchers in other economic sectors to identify the gaps, highlight good potentials of sustainability achievements and recommend necessary actions. This research investigates the future expanding demand of healthcare services; the environmental and economic challenges related to this expand and its environmental and economic impacts and the opportunities to overcome these impacts in order to improve healthcare services sustainability and performance. The research follows a SLR to discover earlier works related to environmental sustainability in buildings and healthcare facilities. The environmental challenges related to expanding in healthcare facilities found in the literature are increase in energy consumption and waste generation. The environmental impacts related to these challenges are excessive CO2 and GHG emissions. The economic impacts are escalations of project expenditures, operating expenditures and utilities expenditures. The research uses SD Analysis, as a methodological approach, to framework and understands different healthcare system elements and to develop models that are representing the dynamic relations between these elements. Bahrain healthcare system is selected as a research context due to the availability of good quality healthcare secondary data, the small size of the country that makes it a good model to implement and test new concepts, the limited country resources, and the country keenness to implement sustainability plans to meet sustainability objectives. This research numerically tests and subsequently, supports the implication of stated environmental and economic challenges. It also develops a number of important technical parameters and indicators such as energy and water benchmarks for different healthcare facilities. The research also determines another two sources of environmental challenges related to expanding in healthcare facilities. The first challenge is excessive water consumption. Availability of enough treated water for healthcare applications, especially in countries with limited fresh water resources and depending on 90% of its water need on desalination like Bahrain, a tangible environmental challenge needs to be addressed. The second one is a group of environmental challenges related to the practicing of healthcare services that can expose personnel and environment to high risks. These challenges need to be efficiently managed to improve the environmental sustainability and the social sustainability of healthcare facilities. The research also investigates the effectiveness of a number of mitigation measures used to overcome the environmental and economic negative impacts, such as using energy efficiency technologies, renewable-based energy resources and waste energy recovery. In this regard, the research numerically tests and subsequently supports the implication of stated environmental and economic impacts and the effectiveness of tested measures in mitigating the undesirable results on healthcare facilities. The developed SD Model, as one of the main contributions of this research, is considered as a strategic planning and decision-making administrative tools to forecast future healthcare facilities demand and required resources. It is also considered as a risk assessment tool to assess environmental challenges related to utilities and its environmental and economic impacts in order to improve healthcare facilities sustainability and performance. The potential of utilities saving and utilities expenditures saving in healthcare buildings are high and it is recommended to work toward energy efficiency and renewable energy deployment to achieve sustainable healthcare buildings. Recovery of energy from Medical Waste incineration to be kept under consideration as it is offsetting double the quantity of CO2e emissions resulting from the incineration process. Safe recycling of wastewater of some healthcare processes is highly recommended as it can reduce water consumption and contributes to the reduction of healthcare facilities CO2e emissions. Sources of gray water and gray water applications must be carefully selected to avoid any contradiction with Infection Control regulations or other healthcare regulations. It is recommended to conduct utilities assessment studies on wide sample of healthcare facilities to avoid low peaks and odd operation periods.
84

A gestão de energia elétrica na indústria - seu suprimento e uso eficiente. / The electrical energy management in the industry - its supply and effective utilization.

Gilberto Tonim 18 September 2009 (has links)
O crescente valor pago pela fatura de energia elétrica sucedendo um período de indisponibilidade quando do racionamento em 2001, concomitantemente com as novas regulamentações do setor elétrico, fizeram com que algumas indústrias buscassem melhor entender o negócio energia elétrica de forma a se precaver de um possível novo racionamento. As indústrias foram em busca de preços mais atrativos, objetivando garantir seu processo produtivo com competitividade. O setor elétrico buscou estimular o investimento privado e o crescimento sustentável do mercado de energia elétrica no Brasil, e também incentivar o usuário final a melhor fazer a gestão dos gastos e consumos de energia elétrica através de novas regulamentações, incentivos à eficiência energética, acelerando a competitividade nos preços de energia elétrica, entre outras ações. Este trabalho apresenta um resumo dos fatos relevantes que ocorreram no setor elétrico brasileiro e cita os principais impactos ocorridos na indústria, a transformação do consumidor em cliente, ou seja, de mero pagador de fatura ao responsável pela escolha do fornecedor e o atual gestor do gasto e do consumo de energia em sua indústria. Esta dissertação propõe um modelo de gestão de energia elétrica baseado em um caso de sucesso ocorrido numa grande indústria de alimentos do Brasil, apresentando os resultados obtidos. / The increasing amount paid for the electricity energy invoice after the period of unavailability on the occasion of the energy rationing in 2001, concurrently with the new regulations of the energy sector, have made some industries pursue a better understanding of the energy business in order to avoid a possible new energy rationing. The companies have also been searching for more attractive prices, aiming at ensuring competitiveness in their production process. The electrical energy sector has sought to stimulate private investment and sustainable growth of the energy market in Brazil, apart from providing incentive for the end user in terms of improving their expenditures and energy consumption management through new regulations and incentives for energy efficiency, accelerating the competitiveness of energy price, among other actions. The contents of this dissertation present a summary of relevant facts that occurred in the Brazilian electricity sector. Moreover, they cite the major impacts on the industry, the transformation of consumers into customers, i.e. from a mere bill payer to a customer who is responsible for choosing the energy provider, also becoming the current expenditure and energy consumption manager of their own company. This dissertation proposes a model of energy management based on a successful case occurred in a major food processing industry in Brazil, presenting the results.
85

Energy management for cloud computing environment. / Gerenciamento de energia para ambiente de computação em nuvem.

Viviane Tavares Nascimento 08 August 2017 (has links)
As one of the major energy consumers in the world, the Information and Communication Technology (ICT) sector searches for efficient ways to cope with the energy expenditure of the infrastructure. One of the areas that tend to grow in the coming years, the Cloud Computing services providers look for approaches to change the energy expenditure pattern, concurrently reducing the operational costs. The most common strategy to cope with the energy consumption is related to its efficiency. However, there is the opportunity to encourage a new demand standard, based on the energy supply and price variation. A management approach that takes into account the uctuation of the energy to negotiate the contracts allocation is proposed. Contractible service terms regarding powering the services are established to enable the proposed management approach. Also, a new service layer able to deal with energy requirements is defined as an element of the Cloud Computing environment. Existing literature does not cope with the different terms of the energy supply and does not apply a management of the contracts simultaneously. The proposed method includes a service terms description, the energy-related service layer definition, and a framework for its implementation. A model designed to validate the approach applies a Use Case that simulates Data Centers (DCs) spread through the metropolitan area of S~ao Paulo. The obtained results show the ability of the model to manage the contracts allocation in accordance to the best exploitation of the self-generated energy. Taking into account the assignment costs range, to both user and services provider, the method negotiates the most affordable contracts assignment regarding the energy supply variation. / Como um dos maiores consumidores de energia do mundo, o setor de Tecnologia da Informação e Comunicação (TIC) busca por maneiras eficientes para lidar com o consumo de energia da infraestrutura. Uma das áreas que tende a crescer nos próximos anos, os provedores de serviço de Computação em Nuvem procuram por abordagens para mudar o padrão de consumo de energia, ao mesmo tempo reduzindo custos operacionais. A estratégia mais comum para lidar com o consumo de energia é relacionada à sua eficiência. No entanto, há a oportunidade para incentivar um novo padrão de demanda por serviços de Computação em Nuvem, baseado na variação do fornecimento e preços da energia. Uma solução que considera a flutuação da energia para negociar a alocação é proposta. Termos de serviços contratáveis referentes a energizar os serviços são estabelecidos para permitir a solução de gerenciamento proposta. Também, uma nova camada de serviço capaz de lidar com requisitos da energia é definida como um elemento do ambiente de Computação em Nuvem. A literatura existente não lida com os diferentes termos do fornecimento da energia e com o gerenciamento de contratos simultaneamente. O método proposto inclui descrição dos termos de serviço, a definição da camada de serviço relacionada à energia e uma metodologia de implementação. Um modelo foi construído para validar a proposta através de um Caso de Uso que simula uma quantidade de Data Centers (DCs) espalhados pela região metropolitana de São Paulo. Os resultados obtidos mostram a capacidade de gerenciar a alocação dos serviços buscando o melhor aproveitamento da energia auto-gerada pelo ambiente. Utilizando do critério de variação dos custos de alocação, tanto para o usuário quanto para o provedor de serviços, o método negocia a alocação mais favorável para os contratos em razão da variação do fornecimento de energia.
86

Plataforma automatizada e normatizada de monitoração, verificação e gestão de índices de energia

Castro, Renato Ely January 2014 (has links)
Este trabalho descreve os requisitos para definição, implantação, manutenção e melhoria de sistemas de gestão de energia no ambiente industrial com um enfoque sistemático no que se refere às rotinas de melhoria contínua para eficiência energética. Para tanto, propôs-se a estruturação de uma plataforma automatizada visando o monitoramento, verificação e gerenciamento de recursos energéticos compatível com um sistema de gestão de energia normatizado, incluindo os requisitos de uso e consumo de energia, além do monitoramento, documentação, comunicação, melhores práticas de projeto, aquisição de equipamentos, sistemas, processos e recursos humanos envolvidos no desempenho energético. A estratégia de análise do uso da energia proposta neste trabalho baseou-se na metodologia de monitoramento e gestão de índices que consiste em uma abordagem sistemática na utilização de recursos energéticos objetivando alcançar o melhor resultado econômico através da gestão permanente do consumo de energia. Além disso, propôs-se a inclusão dessa metodologia como um procedimento na fase de planejamento da norma ISO50001, a qual estabelece os conceitos para a implantação de sistemas de gestão de energia. Visando integrar as ferramentas associadas a este cenário, esta plataforma contempla o uso de um sistema de supervisão associado a um aplicativo (Soft-PLC) que executa a aplicação de controle do uso de energia em um ambiente industrial com automação distribuída compatível com a norma IEC61131. O projeto do aplicativo de controle do uso de energia foi conduzido adotando-se diferentes linguagens de programação definidas na IEC para executar todos os procedimentos de medição, monitoração e gestão exigidos pelo sistema, incluindo análise comparativa com as “melhores práticas”, uso de tecnologias inovadoras, abordagem de produto e serviço, auditoria energética e conformidade com marcos regulatórios. Os resultados decorrentes da adoção de uma plataforma baseada em automação para o gerenciamento energético incluem elevada flexibilidade, adaptabilidade e usabilidade do sistema. Além disso, um projeto de automação neste cenário de plataforma aberta tende a apresentar menores custos de desenvolvimento e implantação. / This work describes the requirements for the definition, implementation, maintenance and improvement of energy management systems in the industrial environment with a systematic approach concerning continuous improvement routines for energy efficiency. For this purpose, it was proposed the establishment of a framework based on automation to implement monitoring, verification and management of energy resources compatible with a standardized energy management system, including requirements for energy use and consumption, in addition to monitoring, documentation, communication, project best practices, equipment acquisition, systems, processes and human resources involved in energy performance. The strategy of energy use analysis proposed in this work is based on the methodology of monitoring and targeting that consists of a systematic approach in the use of energy resources in order to achieve the best economic result through the permanent management of energy consumption. Furthermore, this work includes that system as a procedure in the planning phase of ISO50001 standard which establishes the concepts for energy management systems implementation. In order to aggregate all tools associated to this scenario, this paper proposes the use of a supervisory tool integrated to a real-time software (Soft-PLC) that runs the control application and a factory floor distributed system automation hardware in an IEC61131 compatible environment. The project of the control application of energy use was conducted using different programming languages defined in IEC to perform all the procedures of measurement, monitoring and management required by the system, including comparative analysis with the "best practices", use of innovative technologies, product and service approach, energy audit and compliance with regulatory milestones. The expected results of adopting an automation-based platform for energetic management include system flexibility, adaptability and usability. Besides, a project of automation in this scenario of open platform tends to introduce lower development and deployment costs.
87

Energy management for cloud computing environment. / Gerenciamento de energia para ambiente de computação em nuvem.

Nascimento, Viviane Tavares 08 August 2017 (has links)
As one of the major energy consumers in the world, the Information and Communication Technology (ICT) sector searches for efficient ways to cope with the energy expenditure of the infrastructure. One of the areas that tend to grow in the coming years, the Cloud Computing services providers look for approaches to change the energy expenditure pattern, concurrently reducing the operational costs. The most common strategy to cope with the energy consumption is related to its efficiency. However, there is the opportunity to encourage a new demand standard, based on the energy supply and price variation. A management approach that takes into account the uctuation of the energy to negotiate the contracts allocation is proposed. Contractible service terms regarding powering the services are established to enable the proposed management approach. Also, a new service layer able to deal with energy requirements is defined as an element of the Cloud Computing environment. Existing literature does not cope with the different terms of the energy supply and does not apply a management of the contracts simultaneously. The proposed method includes a service terms description, the energy-related service layer definition, and a framework for its implementation. A model designed to validate the approach applies a Use Case that simulates Data Centers (DCs) spread through the metropolitan area of S~ao Paulo. The obtained results show the ability of the model to manage the contracts allocation in accordance to the best exploitation of the self-generated energy. Taking into account the assignment costs range, to both user and services provider, the method negotiates the most affordable contracts assignment regarding the energy supply variation. / Como um dos maiores consumidores de energia do mundo, o setor de Tecnologia da Informação e Comunicação (TIC) busca por maneiras eficientes para lidar com o consumo de energia da infraestrutura. Uma das áreas que tende a crescer nos próximos anos, os provedores de serviço de Computação em Nuvem procuram por abordagens para mudar o padrão de consumo de energia, ao mesmo tempo reduzindo custos operacionais. A estratégia mais comum para lidar com o consumo de energia é relacionada à sua eficiência. No entanto, há a oportunidade para incentivar um novo padrão de demanda por serviços de Computação em Nuvem, baseado na variação do fornecimento e preços da energia. Uma solução que considera a flutuação da energia para negociar a alocação é proposta. Termos de serviços contratáveis referentes a energizar os serviços são estabelecidos para permitir a solução de gerenciamento proposta. Também, uma nova camada de serviço capaz de lidar com requisitos da energia é definida como um elemento do ambiente de Computação em Nuvem. A literatura existente não lida com os diferentes termos do fornecimento da energia e com o gerenciamento de contratos simultaneamente. O método proposto inclui descrição dos termos de serviço, a definição da camada de serviço relacionada à energia e uma metodologia de implementação. Um modelo foi construído para validar a proposta através de um Caso de Uso que simula uma quantidade de Data Centers (DCs) espalhados pela região metropolitana de São Paulo. Os resultados obtidos mostram a capacidade de gerenciar a alocação dos serviços buscando o melhor aproveitamento da energia auto-gerada pelo ambiente. Utilizando do critério de variação dos custos de alocação, tanto para o usuário quanto para o provedor de serviços, o método negocia a alocação mais favorável para os contratos em razão da variação do fornecimento de energia.
88

MODELING AND ENERGY MANAGEMENT OF HYBRID ELECTRIC VEHICLES

RISHIKESH MAHESH BAGWE (7480409) 17 October 2019 (has links)
<div>This thesis proposes an Adaptive Rule-Based Energy Management Strategy (ARBS EMS) for a parallel hybrid electric vehicle (P-HEV). The strategy can effciently be deployed online without the need for complete knowledge of the entire duty cycle in order to optimize fuel consumption. ARBS improves upon the established Preliminary Rule-Based Strategy (PRBS) which has been adopted in commercial vehicles. When compared to PRBS, the aim of ARBS is to maintain the battery State of Charge (SOC) which ensures the availability of the battery over extended distances. The proposed strategy prevents the engine from operating in highly ineffcient regions and reduces the total equivalent fuel consumption of the vehicle. Using an HEV model developed in Simulink, both the proposed ARBS and the established PRBS strategies are compared across eight short duty cycles and one long duty cycle with urban and highway characteristics. Compared to PRBS, the results show that, on average, a 1.19% improvement in the miles per gallon equivalent (MPGe) is obtained with ARBS when the battery initial SOC is 63% for short duty cycles. However, as opposed to PRBS, ARBS has the advantage of not requiring any prior knowledge of the engine efficiency maps in order to achieve optimal performance. This characteristics can help in the systematic aftermarket hybridization of heavy duty vehicles.</div>
89

Distributed Control of Electric Vehicle Charging: Privacy, Performance, and Processing Tradeoffs

Botkin-Levy, Micah 01 January 2019 (has links)
As global climate change concerns, technological advancements, and economic shifts increase the adoption of electric vehicles, it is vital to study how best to integrate these into our existing energy systems. Electric vehicles (EVs) are on track to quickly become a large factor in the energy grid. If left uncoordinated, the charging of EVs will become a burden on the grid by increasing peak demand and overloading transformers. However, with proper charging control strategies, the problems can be mitigated without the need for expensive capital investments. Distributed control methods are a powerful tool to coordinate the charging, but it will be important to assess the trade-offs between performance, information privacy, and computational speed between different control strategies. This work presents a comprehensive comparison between four distributed control algorithms simulating two case studies constrained by dynamic transformer temperature and current limits. The transformer temperature dynamics are inherently nonlinear and this implementation is contrasted with a piece-wise linear convex relaxation. The more commonly distributed control methods of Dual Decomposition and Alternating Direction Method of Multipliers (ADMM) are compared against a relatively new algorithm, Augmented Lagrangian based Alternating Direction Inexact Newton (ALADIN), as well as against a low-information packetized energy management control scheme (PEM). These algorithms are implemented with a receding horizon in two distinct case studies: a local neighborhood scenario with EVs at each network node and a hub scenario where each node represents a collection of EVs. Finally, these simulation results are compared and analyzed to assess the methods’ performance, privacy, and processing metrics for each case study as no algorithm is found to be optimal for all applications.
90

Load Scheduling with Maximum Demand and Time of Use pricing for Microgrids

ALWAN, HAYDER O 01 January 2019 (has links)
Several demand side management (DSM) techniques and algorithms have been used in the literature. These algorithms show that by adopting DSM and Time-of-Use (TOU) price tariffs; electricity cost significantly decreases, and optimal load scheduling is achieved. However, the purpose of the DSM is to not only lower the electricity cost, but also to avoid the peak load even if the electricity prices low. To address this concern, this dissertation starts with a brief literature review on the existing DSM algorithms and schemes. These algorithms can be suitable for Direct Load Control (DLC) schemes, Demand Response (DR), and load scheduling strategies. \end{abstract} Secondly, the dissertations compares two of DSM algorithms to show the performance based on cost minimization, voltage fluctuation, and system power loss [see in Chapter 5]. The results show the importance of balance between objectives such as electricity cost minimization, peak load occurrence, and voltage fluctuation evolution while simultaneously optimizing the cost.

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