No description available.

A single-phase, buck-boost based, dual-output AC-DC converter is studied in this thesis. The converter has two DC outputs with opposite polarities, which share the same ground with the input power line. The power stage performance, including the input filter, is studied and procedure to select power components is given. The circuit model is analyzed to develop appropriate control. Zerocrossing distortion of the source input current is addressed and a solution is proposed. Experimental results are satisfactory in that a high power factor line current results for steady-state operation.

Orientador: Percival Bueno de Araujo / Resumo: Neste trabalho são apresentados quatro métodos de otimização bio-inspirados, Colônia de Abelhas Artificiais, Otimização por Enxame de Partículas, Algoritmo dos Vagalumes e um híbrido aqui denominado por Bee – PSO, que combina particularidades dos outros três. Estes métodos são utilizados no ajuste coordenado dos parâmetros dos controladores Proporcional-Integral e Suplementares de Amortecimento (Estabilizadores de Sistemas de Potência e o conjunto Unified Power Flow Controller – Power Oscillation Damping). O objetivo é inserir amortecimento adicional aos modos oscilatórios de baixa frequência e, consequentemente, garantir a estabilidade do sistema elétrico frente a pequenas perturbações. São considerados três cenários que englobam duas configurações de instalação dos controladores suplementares e duas condições de carregamento, uma fixa e outra variável. Uma formulação por injeções de corrente do dispositivo Unified Power Flow Controller é sugerida e incorporada ao Modelo de Sensibilidade de Corrente, utilizado para representar o sistema elétrico de potência. Análises estática e dinâmica foram realizadas nos sistemas teste Simétrico de Duas Áreas e New England para validar o modelo de injeções de corrente proposto para o Unified Power Flow Controller e determinar qual dos algoritmos apresentados é o mais eficiente no ajuste coordenado dos parâmetros dos controladores. Dos resultados obtidos foi possível concluir que a versão híbrida proposta neste trabalho possui desempenho s... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work four bio-inspired optimization methods, Artificial Bee Colony, Particle Swarm Optimization, Firefly Algorithm, and a hybrid called Bee – PSO, which combines the characteristics of the other three are presented. These methods are used in the coordinated adjustment of the parameters of Proportional-Integral and Supplementary Damping Controllers (Power System Stabilizers and the Unified Power Flow Controller - Power Oscillation Damping). The goal is to insert additional damping into the low-frequency oscillatory modes and thus ensure the stability of the electrical system against minor disturbances. Three scenarios are considered that include two installation configurations of the supplementary controllers and two charging conditions, one fixed and one variable. A current injection formulation of the Unified Power Flow Controller is suggested and incorporated into the Current Sensitivity Model used to represent the electric power system. Static and dynamic analyzes were performed in the Two-Zone Symmetric and New England test systems to validate the proposed current injection model for the Unified Power Flow Controller and to determine which of the presented algorithms is the most efficient in the coordinated adjustment of the parameters of the controllers. From the results obtained it was possible to conclude that the hybrid version proposed in this work has superior performance in most scenarios analyzed, providing solutions with sufficient damping, even when smal... (Complete abstract click electronic access below) / Doutor

Submitted by LUIS FABIANO BARONE MARTINS null (luis_barone@ig.com.br) on 2017-08-30T14:29:52Z No. of bitstreams: 1 tese-luis-fabiano-barone-martins.pdf: 3400963 bytes, checksum: 6361e93ee21ab8eb5a35cb9dd7d0bd28 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-30T17:52:14Z (GMT) No. of bitstreams: 1 martins_lfb_dr_ilha.pdf: 3400963 bytes, checksum: 6361e93ee21ab8eb5a35cb9dd7d0bd28 (MD5) / Made available in DSpace on 2017-08-30T17:52:14Z (GMT). No. of bitstreams: 1 martins_lfb_dr_ilha.pdf: 3400963 bytes, checksum: 6361e93ee21ab8eb5a35cb9dd7d0bd28 (MD5) Previous issue date: 2017-08-22 / Neste trabalho são apresentados quatro métodos de otimização bio-inspirados, Colônia de Abelhas Artificiais, Otimização por Enxame de Partículas, Algoritmo dos Vagalumes e um híbrido aqui denominado por Bee – PSO, que combina particularidades dos outros três. Estes métodos são utilizados no ajuste coordenado dos parâmetros dos controladores Proporcional-Integral e Suplementares de Amortecimento (Estabilizadores de Sistemas de Potência e o conjunto Unified Power Flow Controller – Power Oscillation Damping). O objetivo é inserir amortecimento adicional aos modos oscilatórios de baixa frequência e, consequentemente, garantir a estabilidade do sistema elétrico frente a pequenas perturbações. São considerados três cenários que englobam duas configurações de instalação dos controladores suplementares e duas condições de carregamento, uma fixa e outra variável. Uma formulação por injeções de corrente do dispositivo Unified Power Flow Controller é sugerida e incorporada ao Modelo de Sensibilidade de Corrente, utilizado para representar o sistema elétrico de potência. Análises estática e dinâmica foram realizadas nos sistemas teste Simétrico de Duas Áreas e New England para validar o modelo de injeções de corrente proposto para o Unified Power Flow Controller e determinar qual dos algoritmos apresentados é o mais eficiente no ajuste coordenado dos parâmetros dos controladores. Dos resultados obtidos foi possível concluir que a versão híbrida proposta neste trabalho possui desempenho superior na maioria dos cenários analisados, fornecendo soluções com amortecimento suficiente, mesmo quando pequenas variações no carregamento do sistema são consideradas. / In this work four bio-inspired optimization methods, Artificial Bee Colony, Particle Swarm Optimization, Firefly Algorithm, and a hybrid called Bee – PSO, which combines the characteristics of the other three are presented. These methods are used in the coordinated adjustment of the parameters of Proportional-Integral and Supplementary Damping Controllers (Power System Stabilizers and the Unified Power Flow Controller - Power Oscillation Damping). The goal is to insert additional damping into the low-frequency oscillatory modes and thus ensure the stability of the electrical system against minor disturbances. Three scenarios are considered that include two installation configurations of the supplementary controllers and two charging conditions, one fixed and one variable. A current injection formulation of the Unified Power Flow Controller is suggested and incorporated into the Current Sensitivity Model used to represent the electric power system. Static and dynamic analyzes were performed in the Two-Zone Symmetric and New England test systems to validate the proposed current injection model for the Unified Power Flow Controller and to determine which of the presented algorithms is the most efficient in the coordinated adjustment of the parameters of the controllers. From the results obtained it was possible to conclude that the hybrid version proposed in this work has superior performance in most scenarios analyzed, providing solutions with sufficient damping, even when small variations in system loading are considered.

No description available.

The focus of this research is on deriving small signal stability models for different Flexible AC Transmission Systems devices by introducing a simple systematic method that is applicable to any dynamic device. Two different small signal models for Unified Power Flow Controllers are introduced. One model is called the power control mode and the other model is the voltage control mode. The two models are compared from transient stability point of view to show the necessity of developing both models for UPFC. The thesis also shows how to derive the small signal stability model of Static Synchronous Compensator, as the shunt branch of UPFC. The small signal stability models of both devices are then validated to ensure the accuracy of the derived models. STATCOM and UPFC power control mode are validated against PSCAD. The UPFC voltage control mode is validated against nonlinear solution of system equations.

The focus of this research is on deriving small signal stability models for different Flexible AC Transmission Systems devices by introducing a simple systematic method that is applicable to any dynamic device. Two different small signal models for Unified Power Flow Controllers are introduced. One model is called the power control mode and the other model is the voltage control mode. The two models are compared from transient stability point of view to show the necessity of developing both models for UPFC. The thesis also shows how to derive the small signal stability model of Static Synchronous Compensator, as the shunt branch of UPFC. The small signal stability models of both devices are then validated to ensure the accuracy of the derived models. STATCOM and UPFC power control mode are validated against PSCAD. The UPFC voltage control mode is validated against nonlinear solution of system equations.

In order to identify the weakest bus in a power system so that the Unified Power Flow Controller could be connected, an investigation of static and dynamic voltage stability is presented. Two stability indices, static and dynamic, have been proposed in the thesis. Multi-Input Multi-Output (MIMO) analysis has been used for the dynamic stability analysis. Results based on the Western System Coordinate Council (WSCC) 3-machine, 9-bus test system and IEEE 14 bus Reliability Test System (RTS) shows that these indices detect with the degree of accuracy the weakest bus, the weakest line and the voltage stability margin in the test system before suffering from voltage collapse. Recently, Flexible Alternating Current Transmission systems (FACTs) have become significant due to the need to strengthen existing power systems. The UPFC has been identified in literature as the most comprehensive and complex FACTs equipment that has emerged for the control and optimization of power flow in AC transmission systems. Significant research has been done on the UPFC. However, the extent of UPFC capability, connected to the weakest bus in maintaining the power flows under fault conditions, not only in the line where it is installed, but also in adjacent parallel lines, remains to be studied. In the literature, it has normally been assumed the UPFC is disconnected during a fault period. In this investigation it has been shown that fault conditions can affect the UPFC significantly, even if it occurred on far buses of the power system. This forms the main contribution presented in this thesis. The impact of UPFC in minimizing the disturbances in voltages, currents and power flows under fault conditions are investigated. The WSCC 3-machine, 9-bus test system is used to investigate the effect of an unsymmetrical fault type and position on the operation of UPFC controller in accordance to the G59 protection, stability and regulation. Results show that it is necessary to disconnect the UPFC controller from the power system during unsymmetrical fault conditions.

Orientador: Percival Bueno de Araujo / Resumo: Este trabalho apresenta o Novel Bat Algorithm com uma nova técnica para realizar o ajuste coordenado dos parâmetros de controladores suplementares de amortecimento (Estabilizadores de Sistemas de Potência e do conjunto Generalized Unified Power Flow Controller – Power Oscillation Damping) em sistemas elétricos de potência multimáquinas. O objetivo principal é inserir amortecimento adicional aos modos oscilatórios de baixa frequência e, consequentemente, garantir a estabilidade do sistema elétrico frente a pequenas perturbações. Para representar o sistema elétrico de potência será utilizado o Modelo de Sensibilidade de Potência. Desse modo, todos os seus dispositivos e componentes foram modelados por injeções de potência. Análises estáticas e dinâmicas foram realizadas em dois sistemas teste, sendo: o Sistema Simétrico de Duas Áreas e o Sistema New England. A eficiência do dispositivo FACTS Generalized Unified Power Flow Controller atuando em conjunto com uma estrutura de controle baseada em controladores Proporcional – Integral foi criteriosamente avaliada para o controle de fluxos de potências ativa e reativa, para a melhoria do perfil de tensão do sistema elétrico e na redução das perdas no sistema de transmissão. O desempenho do Novel Bat Algorithm, no que concerne ao ajuste dos parâmetros dos controladores, foi comparado a outros quatro algoritmos bio-inspirados bastante difundidos na literatura: Particle Swarm Optimization, Bacterial Foragim Optimization, Bat Algorithm e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work presents the Novel Bat Algorithm as a new technique for the to perform the coordinated tuning of the parameters of the supplementary damping controllers (Power Systems Stabilizers and Generalized Unified Power Flow Controller - Power Oscillation Damping) in multi-machine electric power systems. The main objective is to insert damping to low-frequency oscillations and thus ensure the stability of the electrical system against minor disturbances. The Power Sensitivity Model is used to represent the system. Thus, all devices and their components are modeled by power injection. Static and dynamic analyzes were performed in the two systems: the two-areas symmetric, and the New England. The performance of the proposed methodology (Novel Bat Algorithm), for tuning of the parameters of the controllers was compared to four other algorithms, presented in the literature: The Particle Swarm Optimization method, Bacterial Foraging Optimization method, Bat Algorithm method and a Genetic Algorithm with elitism. The results demonstrated that the Novel Bat Algorithm was more effective than the other techniques presented, generating robust solutions when variations on the scenarios of loads were considered, and therefore accredited it as a tool in the analysis of the study of small-signal stability. / Doutor

Submitted by Ednei Luiz Miotto (edneimiotto@utfpr.edu.br) on 2018-11-05T12:58:43Z No. of bitstreams: 1 TESE EDNEI LUIZ MIOTTO.pdf: 5057627 bytes, checksum: 74b7d6f2bd477e7e02941873ca291fa3 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-11-08T19:07:02Z (GMT) No. of bitstreams: 1 miotto_el_dr_ilha.pdf: 5057627 bytes, checksum: 74b7d6f2bd477e7e02941873ca291fa3 (MD5) / Made available in DSpace on 2018-11-08T19:07:02Z (GMT). No. of bitstreams: 1 miotto_el_dr_ilha.pdf: 5057627 bytes, checksum: 74b7d6f2bd477e7e02941873ca291fa3 (MD5) Previous issue date: 2018-10-18 / Este trabalho apresenta o Novel Bat Algorithm com uma nova técnica para realizar o ajuste coordenado dos parâmetros de controladores suplementares de amortecimento (Estabilizadores de Sistemas de Potência e do conjunto Generalized Unified Power Flow Controller – Power Oscillation Damping) em sistemas elétricos de potência multimáquinas. O objetivo principal é inserir amortecimento adicional aos modos oscilatórios de baixa frequência e, consequentemente, garantir a estabilidade do sistema elétrico frente a pequenas perturbações. Para representar o sistema elétrico de potência será utilizado o Modelo de Sensibilidade de Potência. Desse modo, todos os seus dispositivos e componentes foram modelados por injeções de potência. Análises estáticas e dinâmicas foram realizadas em dois sistemas teste, sendo: o Sistema Simétrico de Duas Áreas e o Sistema New England. A eficiência do dispositivo FACTS Generalized Unified Power Flow Controller atuando em conjunto com uma estrutura de controle baseada em controladores Proporcional – Integral foi criteriosamente avaliada para o controle de fluxos de potências ativa e reativa, para a melhoria do perfil de tensão do sistema elétrico e na redução das perdas no sistema de transmissão. O desempenho do Novel Bat Algorithm, no que concerne ao ajuste dos parâmetros dos controladores, foi comparado a outros quatro algoritmos bio-inspirados bastante difundidos na literatura: Particle Swarm Optimization, Bacterial Foragim Optimization, Bat Algorithm e o Algoritmo Genético com Elitismo. Os resultados demonstraram que o Novel Bat Algorithm foi mais eficiente que as demais técnicas avaliadas, obtendo soluções com amortecimento satisfatório, mesmo quando variações nos cenários de carregamento do sistema são consideradas, sendo, portanto, credenciado como ferramenta promissora para a análise da estabilidade a pequenas perturbações em sistemas elétricos de potência multimáquinas. / This work presents the Novel Bat Algorithm as a new technique for the to perform the coordinated tuning of the parameters of the supplementary damping controllers (Power Systems Stabilizers and Generalized Unified Power Flow Controller - Power Oscillation Damping) in multi-machine electric power systems. The main objective is to insert damping to low-frequency oscillations and thus ensure the stability of the electrical system against minor disturbances. The Power Sensitivity Model is used to represent the system. Thus, all devices and their components are modeled by power injection. Static and dynamic analyzes were performed in the two systems: the two-areas symmetric, and the New England. The performance of the proposed methodology (Novel Bat Algorithm), for tuning of the parameters of the controllers was compared to four other algorithms, presented in the literature: The Particle Swarm Optimization method, Bacterial Foraging Optimization method, Bat Algorithm method and a Genetic Algorithm with elitism. The results demonstrated that the Novel Bat Algorithm was more effective than the other techniques presented, generating robust solutions when variations on the scenarios of loads were considered, and therefore accredited it as a tool in the analysis of the study of small-signal stability.