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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.
281

Sensitivity-based Pricing and Multiobjective Control for Energy Management in Power Distribution Systems

January 2012 (has links)
abstract: In the deregulated power system, locational marginal prices are used in transmission engineering predominantly as near real-time pricing signals. This work extends this concept to distribution engineering so that a distribution class locational marginal price might be used for real-time pricing and control of advanced control systems in distribution circuits. A formulation for the distribution locational marginal price signal is presented that is based on power flow sensitivities in a distribution system. A Jacobian-based sensitivity analysis has been developed for application in the distribution pricing method. Increasing deployment of distributed energy sources is being seen at the distribution level and this trend is expected to continue. To facilitate an optimal use of the distributed infrastructure, the control of the energy demand on a feeder node in the distribution system has been formulated as a multiobjective optimization problem and a solution algorithm has been developed. In multiobjective problems the Pareto optimality criterion is generally applied, and commonly used solution algorithms are decision-based and heuristic. In contrast, a mathematically-robust technique called normal boundary intersection has been modeled for use in this work, and the control variable is solved via separable programming. The Roy Billinton Test System (RBTS) has predominantly been used to demonstrate the application of the formulation in distribution system control. A parallel processing environment has been used to replicate the distributed nature of controls at many points in the distribution system. Interactions between the real-time prices in a distribution feeder and the nodal prices at the aggregated load bus have been investigated. The application of the formulations in an islanded operating condition has also been demonstrated. The DLMP formulation has been validated using the test bed systems and a practical framework for its application in distribution engineering has been presented. The multiobjective optimization yields excellent results and is found to be robust for finer time resolutions. The work shown in this report is applicable to, and has been researched under the aegis of the Future Renewable Electric Energy Delivery and Management (FREEDM) center, which is a generation III National Science Foundation engineering research center headquartered at North Carolina State University. / Dissertation/Thesis / Ph.D. Electrical Engineering 2012
282

Smarta Elnät – En utredning : En utredning kring hur ett mindre energibolag kan utveckla sitt elnät till det smartare.

Ekström, Rasmus January 2018 (has links)
The electricity network is in many places facing an eventful future where much will happen in a short period of time. Many network owners today have a network that is somewhat outdated and in short in need of upgrading and modernization, a modernization towards a smarter network. As the government sets new demands on the electricity meter of the future, Sweden's network owners are faced with a lot of other demands and challenges to be addressed. In this work, the definition of smart grids is investigated and how a small electricity grid should prioritize its investments and developments in its grid in a near future.Elnätsbranschen står på många punkter inför en händelserik framtid där mycket kommer att hända på kort tid. Många nätägare står idag med ett nät som är något föråldrat och inom kort i behov av en upprustning och modernisering, en modernisering mot ett smartare elnät. I takt med att regeringen ställer nya krav på framtidens elmätare så ställs Sveriges nätägare inför en hel del andra krav och utmaningar man måste ta itu med. I Detta arbete så undersöks definitionen av smarta elnät och hur en mindre elnätsägare bör prioritera sina investeringar och utvecklingar i sitt elnät i den närmaste framtiden. / Elnätsbranschen står på många punkter inför en händelserik framtid där mycket kommer att hända på kort tid. Många nätägare står idag med ett nät som är något föråldrat och inom kort i behov av en upprustning och modernisering, en modernisering mot ett smartare elnät. I takt med att regeringen ställer nya krav på framtidens elmätare så ställs Sveriges nätägare inför en hel del andra krav och utmaningar man måste ta itu med. I Detta arbete så undersöks definitionen av smarta elnät och hur en mindre elnätsägare bör prioritera sina investeringar och utvecklingar i sitt elnät i den närmaste framtiden.
283

Framework para construção e análise de sistemas de gestão de energia elétrica para consumidores de baixa tensão em Redes Elétricas Inteligentes

Fonseca, Murilo Larroza January 2011 (has links)
As Redes Elétricas Inteligentes podem ser entendidas como o uso intensivo de tecnologias de informação e comunicação nas redes elétricas, permitindo um fluxo bidirecional de informações e eletricidade pela rede, de forma a obter uma infraestrutura capaz de automaticamente monitorar, proteger e otimizar a operação de seus elementos. A modernização da infraestrutura elétrica no sentido das Redes Elétricas Inteligentes é inevitável e trará profundas mudanças em todos os segmentos do sistema elétrico. Embora a tecnologia necessária para essa modernização já exista a um custo razoável, ainda restam várias questões que devem ser resolvidas. Indefinições em relação aos padrões a serem adotados, regulamentações, segurança, privacidade e vários aspectos tecnológicos dificultam uma implementação coerente, adiando essa modernização. Assim, este trabalho busca apresentar esse cenário em relação às Redes Elétricas Inteligentes, investigando as tendências e situação atual. Dentre essas tendências, há um grande interesse em definir e implementar mecanismos que incentivem uma maior conscientização dos consumidores em relação ao seu uso de energia, além de uma participação ativa dos mesmos no mercado de energia. Isso exigirá a utilização de ferramentas que possibilitem a redução de custos através do uso mais eficiente da energia. Assim, é também proposto um framework para a construção e análise dessas ferramentas que buscam auxiliar os consumidores nesse cenário em formação. O framework proposto foi construído utilizando uma abordagem por Sistemas Multiagentes e possibilita a construção, simulação e análise de diversos sistemas, em diferentes cenários, com variados tipos de equipamentos, tanto reais como virtuais, sob diferentes protocolos de comunicação e com a possibilidade de uso de diversos algoritmos para a operação conjunta dos equipamentos. / Smart Grids can be understood as the intensive use of information and communication technologies over the electricity networks, allowing a bidirectional flow of information and electricity through the network. It is a system that tries to optimize the supply and demand of energy through the integration of distributed generation and renewable energy resources, and through the active participation of consumers as well as an intense trade relationship between all the segments of the electricity sector. The modernization of the electrical infrastructure towards Smart Grids is inevitable and it will bring deep changes in all segments of the electrical system. Although the necessary technology for this modernization already exists at a reasonable cost, there are still several issues to be solved. Uncertainties regarding standards to be adopted, regulations, security, privacy and many technological aspects difficult a consistent implementation and, therefore, delay this modernization. Thus, this study aims to present the Smart Grid scenario, by the investigation of its current situation and tendencies. Among these tendencies, there is a great interest to define and implement mechanisms to encourage consumer to take care about their electrical energy use and to stimulate their active participation in the energy market. This will require tools that will help them to reduce costs through a more efficient use of energy. Therefore, this work proposes also a framework for the development and analysis of these tools that help consumers at this scenario under construction. The proposed framework is built using a Multiagent System approach which allows the construction, simulation and analysis of various systems in different scenarios. In addition, it allows the use of several types of equipments, both real and virtual, under different communication protocols and with the possible use of various algorithms for a joint operation of all Smart Grid equipments.
284

Urban Microgrid Design : Case Study of a Neighborhood in Lisbon

Rodrigues, João January 2018 (has links)
Urban microgrids are smart and complex energy systems that help integrate renewables into our cities, turning our neighborhoods into partly energy self-sufficient hubs. Moreover, they create the space for electricity transactions between neighbors, transforming the former consumers into prosumers. The following work proposes the implementation of an urban microgrid to a neighborhood in Lisbon, Portugal. This dissertation’s objective is designing and discovering the optimal photovoltaic and storage capacity, optimal electricity dispatch, effects of distributed energy production in grid voltage and economic viability of such a system. With this purpose, a comprehensive model was elaborated, considering specific site weather data, electric loads, grid topology and utility tariffs. The self-sufficiency of Arco do Cego was found to be 66% in this study, reducing its carbon footprint by 61%. A detailed map of where to place each PV system and battery bank was generated, with specific electricity dispatch strategies. Moreover, the system was designed under real grid voltage, current and power flow constraints.
285

Filtro morfológico aplicado ao controle sem fio das potências de aerogeradores GIGE voltados as Smart Grid

Cardoso, Jacqueline Gomes January 2017 (has links)
Orientador: Prof. Dr. Alfeu Joãozinho Sguarezi Filho / Em um sistema de energia renovável em um ambiente de smart grids, o uso de tecnologias sem fio para transmissão remota de informações de controle às turbinas eólicas requer técnicas modernas para assegurar a qualidade de energia gerada e evitar danos às turbinas e conversores. Neste trabalho, o sistema de controle sem fio robusto para uma turbina eólica com gerador de indução gaiola de esquilo conectada à rede elétrica é proposto. O sistema emprega codificação convolucional e filtragem morfológica para melhorar a qualidade de energia gerada, melhorando a robustez do sistema de controle para os erros canal de propagação de rádio. O desempenho é investigado em termos de distorção harmônica total e respostas do sistema a fim de verificar a qualidade de energia fornecida pela turbina eólica à Smart Grid. Resultados satisfatórios endossam a operabilidade e as vantagens do sistema de controle sem fio proposto / Tese ( doutorado)- Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2017. / In a renewable energy power system inside a smart grid environment, the use of wireless technologies for remote transmitting control information to the wind turbines requires modern techniques to improve the overall generated power quality and prevent damage to the turbines and converters. In this work, a robust wireless control system for a squirrel cage induction wind turbine connected to the power grid is proposed. The system employs convolutional coding and morphological filtering jointly to enhance the generated power quality by improving the robustness of the control system to the errors caused by the radio propagation channel. The performance is investigated in terms of total harmonic distortion and overall system response to verify the power quality delivered by the wind turbine to the grid. The satisfactory results endorse the operability and advantages of the proposed wireless control system.
286

Robust Control of Wide Bandgap Power Electronics Device Enabled Smart Grid

January 2017 (has links)
abstract: In recent years, wide bandgap (WBG) devices enable power converters with higher power density and higher efficiency. On the other hand, smart grid technologies are getting mature due to new battery technology and computer technology. In the near future, the two technologies will form the next generation of smart grid enabled by WBG devices. This dissertation deals with two applications: silicon carbide (SiC) device used for medium voltage level interface (7.2 kV to 240 V) and gallium nitride (GaN) device used for low voltage level interface (240 V/120 V). A 20 kW solid state transformer (SST) is designed with 6 kHz switching frequency SiC rectifier. Then three robust control design methods are proposed for each of its smart grid operation modes. In grid connected mode, a new LCL filter design method is proposed considering grid voltage THD, grid current THD and current regulation loop robust stability with respect to the grid impedance change. In grid islanded mode, µ synthesis method combined with variable structure control is used to design a robust controller for grid voltage regulation. For grid emergency mode, multivariable controller designed using H infinity synthesis method is proposed for accurate power sharing. Controller-hardware-in-the-loop (CHIL) testbed considering 7-SST system is setup with Real Time Digital Simulator (RTDS). The real TMS320F28335 DSP and Spartan 6 FPGA control board is used to interface a switching model SST in RTDS. And the proposed control methods are tested. For low voltage level application, a 3.3 kW smart grid hardware is built with 3 GaN inverters. The inverters are designed with the GaN device characterized using the proposed multi-function double pulse tester. The inverter is controlled by onboard TMS320F28379D dual core DSP with 200 kHz sampling frequency. Each inverter is tested to process 2.2 kW power with overall efficiency of 96.5 % at room temperature. The smart grid monitor system and fault interrupt devices (FID) based on Arduino Mega2560 are built and tested. The smart grid cooperates with GaN inverters through CAN bus communication. At last, the three GaN inverters smart grid achieved the function of grid connected to islanded mode smooth transition / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2017
287

Desenvolvimento de um sistema para aquisição e processamento de sinais utilizando a plataforma TivaWareTM para aplicações em Smart Grid

Lima, Alison Lins de 29 July 2015 (has links)
Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2015-11-24T11:18:29Z No. of bitstreams: 1 arquivototal.pdf: 5459157 bytes, checksum: e363929cf9a6a71b88515b8a24c12af6 (MD5) / Made available in DSpace on 2015-11-24T11:18:29Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5459157 bytes, checksum: e363929cf9a6a71b88515b8a24c12af6 (MD5) Previous issue date: 2015-07-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Amid a scenario, that contrasts the increasing demand for electricity, and decreased ability to generation from conventional sources, which is creating serious problems for the energy sector, the concept of smart grids popularizes up and presented as an alternative to, among other possibilities, minimize the effects of power outages in the design of distributed generation from alternative sources. In order for alternatives to that end, it will develop a data acquisition system, low cost and high performance for applications in smart grids, which facilitates monitoring of electricity in real time, where the user can manage their own control avoiding waste and consequently saving. The system will be developed based on the standards of ANEEL (Brazilian Electricity Regulatory Agency), body responsible for determining the minimum parameters a measuring equipment must possess. The data acquisition system showed results with a high degree of agreement when compared with the reference instrument, the fluke 434/435. A response curve of voltage and current, showing the system behavior compared to other instruments of measurement was introduced. Still, it is objective of the work that the signs Conditioning Unit can be adapted for multiple microprocessor platforms, using simple settings, without the need for hardware reconfiguration. This fact has been proven to be used with Black BeagleBone with satisfactory results. / Em meio a um cenário que contrasta o aumento da demanda por energia elétrica, e a diminuição da capacidade de geração a partir das fontes convencionais, o que vem gerando sérios problemas para o setor energético, o conceito de smart grids populariza-se e apresenta-se como uma alternativa para, entre outras possibilidades, minimizar os efeitos da falta de energia elétrica, na concepção de geração distribuída a partir de fontes alternativas. Com vistas em alternativas com esse fim, será desenvolvido um sistema de aquisição de dados, de baixo custo e alto desempenho, para aplicações em smart grids, que viabilize o monitoramento da energia elétrica em tempo real, onde o usuário possa gerir o seu próprio controle evitando o desperdício e, consequentemente, economizando. O sistema será desenvolvido com base nas normas da ANEEL (Agência Nacional de Energia Elétrica), órgão responsável por determinar os parâmetros mínimos que um equipamento de medição deve possuir. O sistema de aquisição de dados apresentou resultados com alto grau de concordância ao ser comparados com o instrumento de referência, o fluke 434/435. Foi apresentado uma curva resposta da tensão e corrente, mostrando o comportamento do sistema em comparação a de outros instrumentos de medições. Ainda, é objetivo do trabalho que a Unidade de Condicionamento dos Sinais, possa ser adaptada para múltiplas plataformas microprocessadas, através de simples ajustes, sem a necessidade de reconfiguração de hardware. Esse fato foi comprovado ao ser utilizada com a BeagleBone Black, apresentando resultados satisfatórios.
288

Análise de desempenho da rede neural artificial ARTMAP fuzzy aplicada para previsão multi-step de cargas elétricas em diferentes níveis de agregação / Performance analysis of a fuzzy ARTMAP artificial neural network for multi-step forecasting of electric loads at different aggregation levels

Müller, Marcos Ricardo 26 February 2018 (has links)
Submitted by MARCOS RICARDO MÜLLER (marcos.ricardo.unesp@gmail.com) on 2018-04-23T16:13:18Z No. of bitstreams: 1 muller_mr_tese_lv.pdf: 4063915 bytes, checksum: 2bd34db37cecdea37a74a93bf0e348b5 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-04-23T17:10:16Z (GMT) No. of bitstreams: 1 muller_mr_dr_ilha.pdf: 4063915 bytes, checksum: 2bd34db37cecdea37a74a93bf0e348b5 (MD5) / Made available in DSpace on 2018-04-23T17:10:16Z (GMT). No. of bitstreams: 1 muller_mr_dr_ilha.pdf: 4063915 bytes, checksum: 2bd34db37cecdea37a74a93bf0e348b5 (MD5) Previous issue date: 2018-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A maior inserção de tecnologias da informação nas redes de distribuição de energia elétrica vem permitindo que maiores volumes de dados de consumo sejam capturados em níveis cada vez mais detalhados, menos agregados e com maiores resoluções. Com a evolução dos mercados de energia elétrica, esses tipos de dados alcançam maior importância, uma vez que a comercialização de energia também passa a considerar estes níveis de consumo. Diversas técnicas têm sido aplicadas para previsão de cargas elétricas, como modelos estatísticos, de inteligência computacional e híbridos. Na literatura especializada é possível encontrar trabalhos que aplicam a rede neural artificial ARTMAP Fuzzy para tarefas de previsão de cargas elétricas, no entanto, a técnica ainda é pouco explorada em cenários de consumo menos agregados, e com maiores níveis de detalhe. Neste trabalho a rede ARTMAP Fuzzy é aplicada em tarefas de previsão multi-step de cargas elétricas reais com distintos níveis de agregação. Considerando o impacto do ruído sobre os previsores, sobretudo na capacidade de generalização das redes neurais artificiais, a técnica singular spectrum analysis é aplicada na tarefa de remoção de ruído. Os resultados de previsão permitiram analisar desempenho da rede ARTMAP Fuzzy, que foi comparada com outros dois previsores utilizados como benchmark, a saber, seasonal autoregressive integrated moving average e a rede neural multiLayer perceptron. A remoção de ruído permitiu melhora nos níveis de generalização da rede, impactando positivamente sua capacidade preditiva. / The increased insertion of information technologies in electricity distribution networks has allowed larger volumes of consumption data to be captured at increasingly detailed, less aggregated and higher resolution levels. With the evolution of electric energy markets, these types of data become more important, since the commercialization of energy also begins to consider these levels of consumption. Several techniques have been applied to predict electrical loads, such as statistical, computational intelligence and hybrids models. In the specialized literature it is possible to find works that apply the artificial neural network ARTMAP Fuzzy for tasks of prediction of electric charges, however, the technique is still little explored in less aggregated consumption scenarios, and with greater levels of detail. In this work the ARTMAP Fuzzy network is applied in multi-step forecasting tasks of real electric loads with different levels of aggregation. Considering the impact of noise on predictors, especially in the generalization capacity of artificial neural networks, the singular spectrum analysis technique is applied in the noise removal task. The prediction results allowed to analyze the performance of the ARTMAP Fuzzy network, which was compared with other two predictors used as benchmark, namely seasonal autoregressive integrated moving average and the multiLayer perceptron neural network. The noise removal allowed an improvement in the levels of network generalization, positively impacting its predictive capacity. / 1560734
289

Framework para construção e análise de sistemas de gestão de energia elétrica para consumidores de baixa tensão em Redes Elétricas Inteligentes

Fonseca, Murilo Larroza January 2011 (has links)
As Redes Elétricas Inteligentes podem ser entendidas como o uso intensivo de tecnologias de informação e comunicação nas redes elétricas, permitindo um fluxo bidirecional de informações e eletricidade pela rede, de forma a obter uma infraestrutura capaz de automaticamente monitorar, proteger e otimizar a operação de seus elementos. A modernização da infraestrutura elétrica no sentido das Redes Elétricas Inteligentes é inevitável e trará profundas mudanças em todos os segmentos do sistema elétrico. Embora a tecnologia necessária para essa modernização já exista a um custo razoável, ainda restam várias questões que devem ser resolvidas. Indefinições em relação aos padrões a serem adotados, regulamentações, segurança, privacidade e vários aspectos tecnológicos dificultam uma implementação coerente, adiando essa modernização. Assim, este trabalho busca apresentar esse cenário em relação às Redes Elétricas Inteligentes, investigando as tendências e situação atual. Dentre essas tendências, há um grande interesse em definir e implementar mecanismos que incentivem uma maior conscientização dos consumidores em relação ao seu uso de energia, além de uma participação ativa dos mesmos no mercado de energia. Isso exigirá a utilização de ferramentas que possibilitem a redução de custos através do uso mais eficiente da energia. Assim, é também proposto um framework para a construção e análise dessas ferramentas que buscam auxiliar os consumidores nesse cenário em formação. O framework proposto foi construído utilizando uma abordagem por Sistemas Multiagentes e possibilita a construção, simulação e análise de diversos sistemas, em diferentes cenários, com variados tipos de equipamentos, tanto reais como virtuais, sob diferentes protocolos de comunicação e com a possibilidade de uso de diversos algoritmos para a operação conjunta dos equipamentos. / Smart Grids can be understood as the intensive use of information and communication technologies over the electricity networks, allowing a bidirectional flow of information and electricity through the network. It is a system that tries to optimize the supply and demand of energy through the integration of distributed generation and renewable energy resources, and through the active participation of consumers as well as an intense trade relationship between all the segments of the electricity sector. The modernization of the electrical infrastructure towards Smart Grids is inevitable and it will bring deep changes in all segments of the electrical system. Although the necessary technology for this modernization already exists at a reasonable cost, there are still several issues to be solved. Uncertainties regarding standards to be adopted, regulations, security, privacy and many technological aspects difficult a consistent implementation and, therefore, delay this modernization. Thus, this study aims to present the Smart Grid scenario, by the investigation of its current situation and tendencies. Among these tendencies, there is a great interest to define and implement mechanisms to encourage consumer to take care about their electrical energy use and to stimulate their active participation in the energy market. This will require tools that will help them to reduce costs through a more efficient use of energy. Therefore, this work proposes also a framework for the development and analysis of these tools that help consumers at this scenario under construction. The proposed framework is built using a Multiagent System approach which allows the construction, simulation and analysis of various systems in different scenarios. In addition, it allows the use of several types of equipments, both real and virtual, under different communication protocols and with the possible use of various algorithms for a joint operation of all Smart Grid equipments.
290

Hybrid Microgrid Model based on Solar Photovoltaics with Batteries and Fuel Cells system for intermittent applications

January 2013 (has links)
abstract: Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home is collected for use elsewhere within the microgrid footprint. The surplus power that would have been discarded becomes a community asset, and is used to run intermittent services. In this paper, the modeled community does not have parking adjacent to each home allowing for the installment of a privately owned slower Level 2 charger, making EV ownership option untenable. A solution is to provide a Level 3 DC Quick Charger (DCQC) as the intermittent service. The addition of batteries and Fuel Cells are meant to increase load leveling, reliability, and instill limited island capability. / Dissertation/Thesis / M.S.Tech Engineering 2013

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