Power System Stability
Mostrando 13-24 de 102 artigos, teses e dissertações.
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13. MODELOS DE CARGAS BASEADOS EM MEDIÇÕES PARA SIMULAÇÕES DINÂMICAS EM SISTEMAS ELÉTRICOS DE POTÊNCIA / MEASUREMENT-BASED LOAD MODELING FOR DYNAMIC SIMULATIONS ON ELECTRIC POWER SYSTEMS
This work describes a measurement-based load modeling methodology, using voltage and current data registered during power system disturbances. These load models are used on computational simulations for predicting power system stability after disturbances of system operational points. Practical results are presented of the proposed methodology, defining load
Publicado em: 2010
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14. DESENVOLVIMENTO DE METODOLOGIA DO PROJETO DO REATOR ELETRÔNICO AUTO-OSCILANTE COM ENTRADA UNIVERSAL / DEVELOPMENT OF METHODOLOGY OF SELF-OSCILLATING ELECTRONIC BALLAST DESIGN WITH UNIVERSAL INPUT
This work presents the design and analysis of an electronic system with universal input to supply a fluorescent lamp. The system includes a self-oscillating electronic ballast and an additional circuit which allows keeping the nominal lamp power although a variation of the input voltage. The electronic ballast design comprises some steps: resonant filter des
Publicado em: 2010
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15. ROBUST VARIABLE STRUCTURE MODEL REFERENCE ADAPTIVE CONTROL APPLIED TO ACTIVE POWER FILTERS / CONTROLE ADAPTATIVO ROBUSTO DE ESTRUTURA VARIÁVEL POR MODELO DE REFERÊNCIA APLICADO A FILTROS ATIVOS DE POTÊNCIA
This works presents a Robust Variable Structure Model Reference Adaptive Control scheme denoted VSRMRAC. In this adaptive control strategy, each parameter of the control law is obtained by the sum of two other adaptive terms. One of them is associated with the RMRAC algorithm, while the other is composed of an adaptive gain rated by an approximated sign func
Publicado em: 2010
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16. ASPECTOS TÉCNICOS E OPERACIONAIS DO USO DE MICROTURBINAS CONECTADAS AOS SISTMAS ELÉTRICOS PARA GERAÇÃO DISTRIBUÍDA DE ENERGIA / TECHNICAL AND OPERATIONAL ASPECTS OF THE USE OF MICROTURBINES CONNECT TO THE ELECTRICAL SYSTEM FOR DISTRIBUTED ENERGY GENERATION
The considerable increase in energy demand has increased the interest in reducing costs, improving reliability, quality and stability of power generation systems. The connection of distributed generation (DG) can be used as a strategic element to improve the voltage levels in power system. Microturbines (MT) have certain advantages over other models of GD, s
Publicado em: 2010
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17. Análise do impacto da proteção antiilhamento na estabilidade de geradores conectados via inversores / Stability analysis of inverter-based distributed generators with antiislanding protection
O uso de geradores conectados via inversores em redes de distribuição de energia elétrica tem aumentado consideravelmente nos últimos anos em razão dos avanços obtidos nas tecnologias de células a combustível e fotovoltaicas bem como de microturbinas e turbinas eólicas. Nesse contexto, a utilização de sistemas de proteção antiilhamento no ponto
Publicado em: 2010
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18. Estudo teórico sobre meios de determinação de Áreas de Preservação Permanente (APPs) marginais aos cursos d água através da análise de fatores ambientais no âmbito da bacia hidrográfica: enfoque geomorfológico / Theorical study about the determination of the Permanent Preservation Areas (PPAs) marginal to the water courses through the analysis of the environmental factors in the context of the watershed: geomorphology focus
The Permanent Preservation Areas (PPAs) were imposed by New Brazilian Forest Code in order to ensure the stability of the landscape, water and biotic features. Among the types of PPAs are those which protect the marginal portions of the watercourses, which are currently focuses of environmental conflicts, given its regulatory power that overly restricts the
Publicado em: 2010
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19. As bases do novo desenvolvimentismo : análise do governo Lula / The foundations of the new developmentalism in Brazil : analysis of the Lula government (2003-2010)
High concentration of political power and social exclusion strongly marked the development of Brazilian society. These characteristics remained while assuming different forms as a result of changes in the system of production and in the political organization of the State in Brazilian history. The Foreign Debt crisis, at the beginning of the Eighties, and la
Publicado em: 2010
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20. Analysis of the primary control system of a hydropower plant in isolated model
The aim of this work is to study the primary control system of a hydropower plant in isolated mode. The power plant is modeled by differential equations and results are compared to field data from an actual hydropower plant, presenting deviations lower than 1.0%. The study of primary control system is conducted in order to define useful sets of parameters fo
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2009-03
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21. Uma contribuição à alocação de geração distribuída, a inserção de PCHs com máquinas síncronas nos sistemas rurais de média tensão
The present work is about an analysis in the domain of distributed generation (DG) allocation in rural distribution systems; the study takes into account the synchronous machines. In such a way, it was possible to research several impacts caused by DG in distribution systems, such as: the rotor angle stability problem under small disturbances; increase of vo
Publicado em: 2009
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22. Método rápido para avaliação da margem de estabilidade de tensão devido a bifurcação de Hopf / Rapid method for evaluating the margin of voltage stability due to Hopf bifurcation
Despite the increasing development of Hopf bifurcations detection methods for electric power systems in the last decades, some aspects still require to progress, especially with the increasing necessity for higher safety in the electrical energy systems operation. One of these aspects concerns to the processing time of these methodologies to be used in real-
Publicado em: 2009
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23. AVALIAÇÃO E REFORÇO DAS CONDIÇÕES DE ESTABILIDADE DE TENSÃO EM BARRAS DE TENSÃO CONTROLADA POR GERADORES E COMPENSADORES SÍNCRONOS / VOLTAGE STABILITY ASSESSMENT AND ENHANCEMENT IN VOLTAGE-CONTROLLED BUSES BY SYNCHRONOUS GENERATORS AND COMPENSATORS
After the incidence of some voltage collapses in the energy transmission systems in the world, the voltage security became an issue of great interest in the last years due to the importance of its impact. The phenomenon of voltage stability is due to the excessive active and reactive power flow in the electrical transmission network and has been associated w
Publicado em: 2009
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24. Utilização do elo de corrente continua para o amortecimento de oscilações eletromecanicas em sistemas eletricos de potencia / Use of the direct current link for the electromechanical oscillations damping in electric power systems
This dissertation presents a study about the HVDC (High Voltage Direct Current) link contribution for damping low frequency electromechanical oscillations when Electric Energy System suffers small-signal disturbances. The HVDC link components models were included in the Power Flow method as well as the steady-state characteristics of the dynamic devices (cur
Publicado em: 2009