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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.
61

Aplicação do método de imagens complexas ao cálculo de malhas de aterramento em solos com estratificação horizontal. / Modelling of grounding grids in multilayer soils using complex images.

Mário Leite Pereira Filho 21 May 1999 (has links)
O projeto de malhas de aterramento requer o cálculo da resistência de aterramento e dos potenciais na superfície do solo. Quando o método das imagens é utilizado para este cálculo o modelo típico do solo é uma estratificação horizontal em 2 camadas. A extensão do método das imagens para solos com múltiplas camadas horizontais apresenta problemas numéricos importantes, de forma que a técnica de imagens complexas foi utilizada para permitir este cálculo, porém restringindo a posição dos eletrodos à primeira camada. Este trabalho objetiva a aplicação do método de imagens complexas a eletrodos situados em qualquer camada de solos com estratificação horizontal, deduzindo as funções kernel para posições arbitrárias da fonte e do objeto e determinando os resíduos e pólos das imagens utilizando a decomposição em autovalores e autovetores. Foi desenvolvido um programa que calcula a resistência de aterramento e os potenciais na superfície do solo para solos com até 4 camadas. Foram realizadas comparações com outros trabalhos publicados e os resultados obtidos permitem validar o uso do programa para esta aplicação. / Grounding grid design requires both ground resistance and surface potential. Traditional method of images restricts this calculation to two layer soils. Complex image method allows calculation of both resistance values and potentials at the soil surface, in multilayer soils with horizontal stratification, without grounding grid position limitation. This work presents a complete methodology for calculation of safety aspects of grounding grid design, validating results by comparison with published previous work.
62

Modelagem das funções de uma subestação automatizada empregando modelos orientadosa objeto. / Modeling the functions of an automated substation with object oriented models.

Serna Silva, Milthon 23 April 2002 (has links)
Trata-se de um estudo descritivo, exploratório sobre a técnica da modelagem de objetos aplicados como interface de comunicação entre os equipamentos de campo de uma subestação elétrica, utilizando o padrão “Utility Communications Architecture - Generic Object Models for Substation & Feeder Equipment" que permite a redução da quantidade de protocolos com os quais trabalham os diferentes equipamentos de campo de uma subestação em geral. A pesquisa procurou explicar quais são as características de uma subestação automatizada (requisitos e comportamento), em que consiste essa nova tecnologia da modelagem de objetos e suas aplicações dentro dos sistemas elétricos. O trabalho explica e aplica os diferentes modelos contidos no padrão dentro das funções de proteção, medição, controle, etc, de uma Subestação Elétrica. Estes modelos são incluídos nos novos equipamentos que levam a informação dos sensores e atuadores colocados nos equipamentos de campo a seu respectivo sistema “Supervisory Control & Data Acquisition". Os novos equipamentos permitem realizar tarefas como sistema de eleição “voting", função de bloqueio de barramento “bus blocking", função de rejeição de carga “load shedding", entre outros, de uma maneira mais eficaz aumentando, assim o desempenho do trabalho da subestação. Como aplicação final, trata de fazer a modelagem de comunicação dos equipamentos de campo da subestação de Bateias, da Companhia Paranaense de Energia com o emprego dos equipamentos providos pelos principais fornecedores do mercado brasileiro: General Electric, Siemens e ABB; tendo para isso como esquemas de referência os modelos das subestações apresentadas na bibliografia. A modelagem demonstrou ser eficaz na comunicação dos equipamentos de campo de uma Subestação Elétrica, já que é possível mediante a mesma padronizar os protocolos que utiliza, permitindo assim a compatibilidade entre os equipamentos de diferentes fabricantes com a respectiva redução dos custos dos projetos de implementação, programação e treinamento dentro da subestação. / This is a descriptive study concerning the modeling technique applying object-oriented models for a communication interface among the equipments in the field of an electric substation. The standard architecture UCA - Utility Communications Architecture and GOMSFE - Generic Object Models for Substation & Feeder Equipment are used, allowing the reduction of the number of protocols in the different equipment's in the yard. This work also addresses the characteristics and the requisites of an automated substation, in what this new modeling technology is about and its applications for the electric power systems. The different models used for the functions of protection, measurement, control, etc. of an Electric Substation are considered, including the new equipment which carry the information from sensors and actuators in the field to their respective SCADA - Supervisory Control & Data Acquisition - system. The performance of the substation is enhanced by new functions as “voting" in protection relays, “bus blocking" in busbars, "load shedding" in load dispatch. Finally the modeling of the communication functions of the field equipments in the substation Bateias, of Copel - Companhia Paranaense de Energia Elétrica is carried out. The equipment's are the ones found in the Brazilian electric market and the reference schemes are from the bibliography. It is shown that the modeling is effective for the communication among the equipment's in the field of an electric substation, and that it is possible to standardize the different protocols employed there. Consequently the compatibility among the equipment's from different manufacturers occurs, and also the reduction of the costs of implementation, programming and personnel training within the substation.
63

Um modelo de integração entre os padrões IEC 61850 e IEC 61970 (CIM/ XML). / An integration model between the IEC 61850 and IEC 61970 standards.

Rein Junior, Osvaldo 13 March 2006 (has links)
REIN JR., O. UM MODELO DE INTEGRAÇÃO ENTRE OS PADRÕES IEC 61850 E IEC 61970 (CIM/XML). 2006. 98 p. Dissertação Mestrado – Escola Politécnica, Universidade de São Paulo, São Paulo. A troca de informação entre os vários sistemas de gerenciamento e outros sistemas de informação de uma empresa do setor elétrico não é apenas desejada, mas, na maioria dos casos, necessária. Dois padrões internacionais surgiram, um relacionado à troca de dados nas subestações (IEC 61850) e outro relacionado à troca de informações entre os centros de controle (IEC 61970), sendo ambos publicados pelo comitê técnico 57 (TC57) do IEC, cujo tema é o gerenciamento e a troca de informação associados aos sistemas de potência. Contudo, apesar da similaridade em seu domínio de aplicação, cada um tem seu próprio modelo de objetos. O presente trabalho tem por objetivo investigar como a integração dos dados pertencentes aos sistemas de controle da subestação e do centro de controle pode ser alcançada, de maneira a permitir que a topologia de uma determinada subestação possa ser conhecida pelo EMS/SCADA. Vale, ainda, ter em conta que a verificação de tal análise demanda a implementação de um protótipo simulando a arquitetura de integração proposta. Logo, o estudo contempla as anotações que refletem os passos dessa implementação, bem como o registro dos testes exigidos pelos trabalhos, os quais compreenderam informações sobre a configuração de uma subestação contidos num arquivo SCL, informações de tempo real obtidas a partir de dispositivos eletrônicos inteligentes (IEDs), e a gravação desses dados em uma base de dados relacional modelada de acordo com o Common Information Model (CIM) contido na IEC 61970-301. / REIN JR., O An integration model between the IEC 61850 and IEC 61970 standards. 2006. 98 p. Dissertação Mestrado – Escola Politécnica, Universidade de São Paulo, São Paulo. The exchange of information among several management systems and other information systems of an electric utility company is not only desired but in most cases needed. Two international standards have emerged, one related to the data exchange of substations (IEC 61850) and another related to the exchange of information among control centers (IEC 61970), both published by the IEC technical committee 57 (TC57) that deals with the management and exchange of information on power systems. Nevertheless, in spite of the similarity in its application domain, each standard has its own object model. This work intends to investigate how to achieve the integration of data belonging to the substation control and control center systems, thus allowing a specific substation topology to be known by the EMS/SCADA. It is important to emphasize that the verification of such analysis required the implementation of a prototype to simulate the proposed integration architecture. Therefore, this work includes notes describing the implementation steps, as well as the record of the tests that have been done, encompassing substation configuration information within a SCL file, real-time information obtained from intelligent electronic devices (IEDs) and data recording in a relational database modeled according to the Common Information Mode (CIM) comprised in the IEC 61970-301.
64

Modelagem das funções de uma subestação automatizada empregando modelos orientadosa objeto. / Modeling the functions of an automated substation with object oriented models.

Milthon Serna Silva 23 April 2002 (has links)
Trata-se de um estudo descritivo, exploratório sobre a técnica da modelagem de objetos aplicados como interface de comunicação entre os equipamentos de campo de uma subestação elétrica, utilizando o padrão “Utility Communications Architecture - Generic Object Models for Substation & Feeder Equipment” que permite a redução da quantidade de protocolos com os quais trabalham os diferentes equipamentos de campo de uma subestação em geral. A pesquisa procurou explicar quais são as características de uma subestação automatizada (requisitos e comportamento), em que consiste essa nova tecnologia da modelagem de objetos e suas aplicações dentro dos sistemas elétricos. O trabalho explica e aplica os diferentes modelos contidos no padrão dentro das funções de proteção, medição, controle, etc, de uma Subestação Elétrica. Estes modelos são incluídos nos novos equipamentos que levam a informação dos sensores e atuadores colocados nos equipamentos de campo a seu respectivo sistema “Supervisory Control & Data Acquisition”. Os novos equipamentos permitem realizar tarefas como sistema de eleição “voting”, função de bloqueio de barramento “bus blocking”, função de rejeição de carga “load shedding”, entre outros, de uma maneira mais eficaz aumentando, assim o desempenho do trabalho da subestação. Como aplicação final, trata de fazer a modelagem de comunicação dos equipamentos de campo da subestação de Bateias, da Companhia Paranaense de Energia com o emprego dos equipamentos providos pelos principais fornecedores do mercado brasileiro: General Electric, Siemens e ABB; tendo para isso como esquemas de referência os modelos das subestações apresentadas na bibliografia. A modelagem demonstrou ser eficaz na comunicação dos equipamentos de campo de uma Subestação Elétrica, já que é possível mediante a mesma padronizar os protocolos que utiliza, permitindo assim a compatibilidade entre os equipamentos de diferentes fabricantes com a respectiva redução dos custos dos projetos de implementação, programação e treinamento dentro da subestação. / This is a descriptive study concerning the modeling technique applying object-oriented models for a communication interface among the equipments in the field of an electric substation. The standard architecture UCA - Utility Communications Architecture and GOMSFE - Generic Object Models for Substation & Feeder Equipment are used, allowing the reduction of the number of protocols in the different equipment's in the yard. This work also addresses the characteristics and the requisites of an automated substation, in what this new modeling technology is about and its applications for the electric power systems. The different models used for the functions of protection, measurement, control, etc. of an Electric Substation are considered, including the new equipment which carry the information from sensors and actuators in the field to their respective SCADA - Supervisory Control & Data Acquisition - system. The performance of the substation is enhanced by new functions as “voting” in protection relays, “bus blocking” in busbars, "load shedding" in load dispatch. Finally the modeling of the communication functions of the field equipments in the substation Bateias, of Copel - Companhia Paranaense de Energia Elétrica is carried out. The equipment's are the ones found in the Brazilian electric market and the reference schemes are from the bibliography. It is shown that the modeling is effective for the communication among the equipment's in the field of an electric substation, and that it is possible to standardize the different protocols employed there. Consequently the compatibility among the equipment's from different manufacturers occurs, and also the reduction of the costs of implementation, programming and personnel training within the substation.
65

Um modelo de integração entre os padrões IEC 61850 e IEC 61970 (CIM/ XML). / An integration model between the IEC 61850 and IEC 61970 standards.

Osvaldo Rein Junior 13 March 2006 (has links)
REIN JR., O. UM MODELO DE INTEGRAÇÃO ENTRE OS PADRÕES IEC 61850 E IEC 61970 (CIM/XML). 2006. 98 p. Dissertação Mestrado – Escola Politécnica, Universidade de São Paulo, São Paulo. A troca de informação entre os vários sistemas de gerenciamento e outros sistemas de informação de uma empresa do setor elétrico não é apenas desejada, mas, na maioria dos casos, necessária. Dois padrões internacionais surgiram, um relacionado à troca de dados nas subestações (IEC 61850) e outro relacionado à troca de informações entre os centros de controle (IEC 61970), sendo ambos publicados pelo comitê técnico 57 (TC57) do IEC, cujo tema é o gerenciamento e a troca de informação associados aos sistemas de potência. Contudo, apesar da similaridade em seu domínio de aplicação, cada um tem seu próprio modelo de objetos. O presente trabalho tem por objetivo investigar como a integração dos dados pertencentes aos sistemas de controle da subestação e do centro de controle pode ser alcançada, de maneira a permitir que a topologia de uma determinada subestação possa ser conhecida pelo EMS/SCADA. Vale, ainda, ter em conta que a verificação de tal análise demanda a implementação de um protótipo simulando a arquitetura de integração proposta. Logo, o estudo contempla as anotações que refletem os passos dessa implementação, bem como o registro dos testes exigidos pelos trabalhos, os quais compreenderam informações sobre a configuração de uma subestação contidos num arquivo SCL, informações de tempo real obtidas a partir de dispositivos eletrônicos inteligentes (IEDs), e a gravação desses dados em uma base de dados relacional modelada de acordo com o Common Information Model (CIM) contido na IEC 61970-301. / REIN JR., O An integration model between the IEC 61850 and IEC 61970 standards. 2006. 98 p. Dissertação Mestrado – Escola Politécnica, Universidade de São Paulo, São Paulo. The exchange of information among several management systems and other information systems of an electric utility company is not only desired but in most cases needed. Two international standards have emerged, one related to the data exchange of substations (IEC 61850) and another related to the exchange of information among control centers (IEC 61970), both published by the IEC technical committee 57 (TC57) that deals with the management and exchange of information on power systems. Nevertheless, in spite of the similarity in its application domain, each standard has its own object model. This work intends to investigate how to achieve the integration of data belonging to the substation control and control center systems, thus allowing a specific substation topology to be known by the EMS/SCADA. It is important to emphasize that the verification of such analysis required the implementation of a prototype to simulate the proposed integration architecture. Therefore, this work includes notes describing the implementation steps, as well as the record of the tests that have been done, encompassing substation configuration information within a SCL file, real-time information obtained from intelligent electronic devices (IEDs) and data recording in a relational database modeled according to the Common Information Mode (CIM) comprised in the IEC 61970-301.
66

Desenvolvimento de algoritmo de controle de tração para regeneração de energia metroviária - ACTREM: melhoria da eficiência energética de sistemas de tração metroviária. / Development traction control algorithm for subway energy regeneration - ACTREM: improving the energy efficiency of subway traction systems.

Carlos Alberto de Sousa 01 September 2015 (has links)
Esta tese propõe um modelo de regeneração de energia metroviária, baseado no controle de paradas e partidas do trem ao longo de sua viagem, com o aproveitamento da energia proveniente da frenagem regenerativa no sistema de tração. O objetivo é otimizar o consumo de energia, promover maior eficiência, na perspectiva de uma gestão sustentável. Aplicando o Algoritmo Genético (GA) para obter a melhor configuração de tráfego dos trens, a pesquisa desenvolve e testa o Algoritmo de Controle de Tração para Regeneração de Energia Metroviária (ACTREM), usando a Linguagem de programação C++. Para analisar o desempenho do algoritmo de controle ACTREM no aumento da eficiência energética, foram realizadas quinze simulações da aplicação do ACTREM na linha 4 - Amarela do metrô da cidade de São Paulo. Essas simulações demonstraram a eficiência do ACTREM para gerar, automaticamente, os diagramas horários otimizados para uma economia de energia nos sistemas metroviários, levando em consideração as restrições operacionais do sistema, como capacidade máxima de cada trem, tempo total de espera, tempo total de viagem e intervalo entre trens. Os resultados mostram que o algoritmo proposto pode economizar 9,5% da energia e não provocar impactos relevantes na capacidade de transporte de passageiros do sistema. Ainda sugerem possíveis continuidades de estudos. / This thesis proposes a subway energy regeneration model, based on control stops and train departures throughout his trip, with the use of energy from the regenerative braking in the drive system. The goal is to optimize the power consumption, improve efficiency, in view of sustainable management. Applying Genetic Algorithm (GA) to get the better of the trains traffic configuration, the research develops and tests the Traction Control Algorithm for Subway Energy Regeneration (ACTREM), using the C ++ programming language. To analyze the performance of ACTREM control algorithm in enhancing energy efficiency, there were fifteen simulations of applying ACTREM on line 4 - Yellow subway in São Paulo. These simulations showed the ACTREM efficiency to generate automatically diagrams schedules optimized for energy savings in metro systems, taking into account the system\'s operational constraints such as maximum each train capacity, total wait time, total travel time and interval between trains. The results show that the proposed algorithm can save 9.5% of the energy and not cause significant impacts on the transportation system capacity passengers. Also suggest possible continuities studies.
67

Grounding Design Analysis

Aydiner, Mustafa Guclu 01 February 2009 (has links) (PDF)
This thesis investigates problematic cases in AC substation grounding system design. Particularly, the grounding design for substations that are built on high resistivity soil is considered. Here, possible physical rectification schemes are introduced and compared for their effectiveness from safety and cost efficiency perspectives. For this comparison, the CYMGRD program (a finite element analysis tool for AC substation grounding) is used for detailed analysis of the various schemes. An additional computer program is developed to implement the formulations of the related AC substation standards (IEEE, IEE, and Turkish National Regulations). The output of this program is compared with the finite element analysis of the high-resistivity-soil rectification schemes to investigate the validity of the formulations in these standards.
68

Analyzing Substation Automation System Reliability using Probabilistic Relational Models and Enterprise Architecture

König, Johan January 2014 (has links)
Modern society is unquestionably heavily reliant on supply of electricity. Hence, the power system is one of the important infrastructures for future growth. However, the power system of today was designed for a stable radial flow of electricity from large power plants to the customers and not for the type of changes it is presently being exposed to, like large scale integration of electric vehicles, wind power plants, residential photovoltaic systems etc. One aspect of power system control particular exposed to these changes is the design of power system control and protection functionality. Problems occur when the flow of electricity changes from a unidirectional radial flow to a bidirectional. Such an implication requires redesign of control and protection functionality as well as introduction of new information and communication technology (ICT). To make matters worse, the closer the interaction between the power system and the ICT systems the more complex the matter becomes from a reliability perspective. This problem is inherently cyber-physical, including everything from system software to power cables and transformers, rather than the traditional reliability concern of only focusing on power system components. The contribution of this thesis is a framework for reliability analysis, utilizing system modeling concepts that supports the industrial engineering issues that follow with the imple-mentation of modern substation automation systems. The framework is based on a Bayesian probabilistic analysis engine represented by Probabilistic Relational Models (PRMs) in com-bination with an Enterprise Architecture (EA) modeling formalism. The gradual development of the framework is demonstrated through a number of application scenarios based on substation automation system configurations. This thesis is a composite thesis consisting of seven papers. Paper 1 presents the framework combining EA, PRMs and Fault Tree Analysis (FTA). Paper 2 adds primary substation equipment as part of the framework. Paper 3 presents a mapping between modeling entities from the EA framework ArchiMate and substation automation system configuration objects from the IEC 61850 standard. Paper 4 introduces object definitions and relations in coherence with EA modeling formalism suitable for the purpose of the analysis framework. Paper 5 describes an extension of the analysis framework by adding logical operators to the probabilistic analysis engine. Paper 6 presents enhanced failure rates for software components by studying failure logs and an application of the framework to a utility substation automation system. Finally, Paper 7 describes the ability to utilize domain standards for coherent modeling of functions and their interrelations and an application of the framework utilizing software-tool support. / <p>QC 20140505</p>
69

Offshore Marine Substation for Grid-Connection of Wave Power Farms : An Experimental Approach

Ekström, Rickard January 2014 (has links)
Wave power is a renewable energy source with great potential, which is why there are more than a hundred ongoing wave power projects around the world. At the Division of Electricity, Uppsala University, a point-absorber type wave energy converter (WEC) has been proposed and developed. The WEC consists of a linear synchronous generator placed on the seabed, connected to a buoy floating on the surface. Power is absorbed by heave motion of the buoy, and converted into electric energy by the generator. The point-absorber WEC must be physically much smaller than the wavelength of the incoming waves, and can therefore not be scaled to very high power levels. Instead, the total power output is boosted by increasing the number of WECs, connecting them in wave power farms. To transfer the electric energy to the grid, an intermediate marine substation is proposed, where an AC/DC/AC conversion step is performed. Within this PhD-work, a full-scale offshore marine substation has been designed, constructed and experimentally evaluated. The substation is rated for grid-connection of seven WECs to the local 1kV-grid, and is placed on the seabed 3km off the coast at a depth of 25m. Various aspects of the substation design have been considered, including the mechanical and electrical systems, the WEC electrical interface, offshore operations and the automatic grid connection control system. A tap change circuit and different multilevel topologies have also been proposed. This dissertation has an experimental approach, validating a major part of the work with lab results. The final substation electrical circuit has been tested at rated grid voltage with a fluctuating input power source. The efficiency has been measured and the implemented functions are verified. Offshore operations have been successfully carried out and offshore wave farm data is expected in the nearby future.
70

民眾對變電所用地多目標使用認知之研究-以大安超高壓變電所為例 / The study of residents' perception of multi-use for substation-Da'an extra high voltage substation as case study

詹翔諭, Chan, Hsiang Yu Unknown Date (has links)
變電所是電力的轉換站,其功能在於降低電壓並分配電力,如變電所裝置容量不足以供應地區用電需求,則會有限電、停電的風險,但由於變電所影響周遭環境景觀與房地產價值的負面外部性,以及民眾對於公共安全與電磁場危害健康的疑慮,以致民眾多不願意變電所設置在自家附近,甚至群起抗爭反對興建變電所。而變電所用地多目標使用規劃正是為了減低傳統屋外式變電所帶來的負面外部性,改善民眾對於變電所為鄰避設施的刻板印象,以期順利推動變電所興建工程,因應日益增加的用電需求,然而民眾面對興建多目標變電所的態度與立場,仍取決於其對變電所用地多目標使用的認知。 本研究關注於民眾面對台電公司興建多目標變電所的認知與行動,以社會資本理論及社會認知理論為立論基礎,選取台電公司興建中「大安超高壓變電所多目標使用大樓」為研究案例,擇其周遭一定鄰里範圍,透過問卷調查及因素分析,萃取出民眾對於多目標變電所開發案採取行動意願的影響因素為:社會網絡、信任關係、多目標使用社會認知及反對行動等四個潛在變數,後續再利用結構方程模式驗證潛在變數之間的影響關係模式,實證結果發現社會網絡對於信任關係有正向影響,信任關係對於多目標使用社會認知亦為正向影響,而多目標使用社會認知對於反對行動則為反向的影響關係。 / The substation is the switching station of electric power, the function of which is to reduce the voltage and distribute power. If the substation capacity is insufficient for the regional power demand, there is a risk of limitation of the power supply or even power failure. However, due to the fact that a substation affects the surrounding environmental landscape and has a negative effect on real estate value, added to the fact that the public has doubts over the use of electromagnetic fields as they are harmful to public safety and health, the public are generally unwilling to agree to a substation being built near their house or even actively protest it. While the planning of multi-use for substation land is designed to reduce the negative impact of a traditional outdoor substation, improve the stereotype of the substation as a NIMBY facility to the public, and expect to smoothly promote substation construction work, to respond to the increasing demand for electric power, the attitude and standpoint of the public to the multi-use substation construction still depends on the cognition of multi-use for substation land. This study focuses on the cognition and action of the public facing the multi-use substation construction of Taipower, social capital theory and social cognitive theory as the theoretical foundation. It also uses “Da'an Extra High Voltage Multi-use Substation” of Taipower under construction as the study case, and through the adoption of a questionnaire survey within a certain neighborhood range and factor analysis, extracts the action-willing influence factors of the public to the multi-use substation development case. The four latent variables of the social network, trust relationship, social cognition of multi-use for substation land, and opposing action, and then uses the structural equation model to verify the influence relation mode of latent variables. The empirical result shows social networks have a positive influence on the trust relationship, and the trust relationship also has a positive influence on the social cognition of multi-use for substation land. However, social cognition of multi-use for substation land has a negative influence on opposing action.

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