Lucas Encarnação | Universidade Federal do Espirito Santo (original) (raw)
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Papers by Lucas Encarnação
2020 11th International Renewable Energy Congress (IREC), 2020
The development of a thermochemical and electrical model that enables to provide of the solid oxi... more The development of a thermochemical and electrical model that enables to provide of the solid oxide fuel cell operation in different conditions is presented in this paper. The validation is carried out by comparing the proposed model with results in the literature for several SOFCs. This model allows to reproduce the expected values of SOFC key variables to be quickly obtain without requiring complex software, as illustrated for a case study.
Raquel Frizera Vassallo∗ Lucas Frizera Encarnaçao∗ José Santos-Victor Hans Jörg Schneebeli∗ ∗UF... more Raquel Frizera Vassallo∗ Lucas Frizera Encarnaçao∗ José Santos-Victor Hans Jörg Schneebeli∗ ∗UFES - Universidade Federal do Espırito Santo Av. Fernando Ferrari s/n - Dep. Engenharia Elétrica, Vitória, ES, Brasil ... ISR/IST - Instituto de Superior Técnico ...
This paper proposes a predictive current control (PCC) strategy with a field orientation applied ... more This paper proposes a predictive current control (PCC) strategy with a field orientation applied on a three-level neutral point clamped (NPC) inverter to drive a three-phase induction motor. It was used the optimal switching vector (OSV) strategy, which is most suitable for power electronics. The field orientation, along with a rotor flux estimation, made it possible to implement a control loop measuring only stator voltage, stator current and rotor speed. The simulation results showed that the average estimated rotor flux error was 0.03%, the total harmonic distortion (THD) for the stator current was 9.29%, and the average stator current error was 5.82%. The proposed model proved to be a viable option to industrial plants, especially when compared with classical controllers.
Energies
This paper proposes a new cascaded multilevel converter topology based on three-phase H bridge ce... more This paper proposes a new cascaded multilevel converter topology based on three-phase H bridge cells with a common DC-link structure. The proposed multilevel converter topology main advantages, compared with literature renowned multilevel converters topologies, are discussed in the paper, such as modularity, construction, implementation cost, and DC voltage ripple mitigation. Despite presenting an elementary structure and easy implementation, the use of classic PWM switching strategies is not feasible for this topology, causing the appearance of several short-circuit states between its capacitors. Thus, a graph theory algorithm combined with a model predictive control is also proposed in this work to identify and avoid the new cascaded multilevel converter short-circuit switching states and, concomitantly, guaranteeing the converter output power quality. In order to validate the presented topology applicability, a low voltage synchronous static compensators (STATCOM) with an optimal...
Electronics
Recently, many non-conventional three-phase inverters, topologies for green energy source grid-co... more Recently, many non-conventional three-phase inverters, topologies for green energy source grid-connection systems, and electric drives have been proposed. Simplifying the inverter circuit is crucial to analyze and solve their models in order to design them. The main goal of the study is centered on obtaining a single-phase equivalent circuit and space state model from non-conventional three-phase inverters based on bidirectional direct current–direct current (DC–DC) Buck-Boost topology using isolated gate bipolar transistors (IGBT). From just one phase of the three-phase inverter, the single-phase equivalent circuit was obtained by means of Kirchhoff’s laws. The equivalent circuit operation steps were presented in order to obtain the space state model. Finally, the equivalent circuit was simulated, and experimental results with a 200 W three-phase inverter feeding a resistive, inductive, and capacitive loads were performed to confirm the theoretical and simulation analyses. The resu...
Eletrônica de Potência
Resumo-Este artigo apresenta uma proposta de modulação híbrida, combinando a modulação em degrau ... more Resumo-Este artigo apresenta uma proposta de modulação híbrida, combinando a modulação em degrau convencional com a modulação PWM (Pulse Width Modulation) descontínua, aplicada aos conversores multiníveis em cascata assimétricos. O desempenho da modulação híbrida proposta neste trabalho será comparada com duas estratégias híbridas convencionais por meio de resultados de simulação e experimentais. O conversor multinível implementado é composto por três inversores monofásicos, em ponte completa, por fase. Por fim, um compensador síncrono estático aplicado a redes de distribuição de média tensão (DSTATCOM) é implementado no intuito de validar experimentalmente a estratégia de modulação proposta.
Brazilian Journal of Development
International Journal of Hydrogen Energy
Revista Ifes Ciência
O processo de reconfiguração da rede elétrica visa atender a critérios técnico-econômicos como o ... more O processo de reconfiguração da rede elétrica visa atender a critérios técnico-econômicos como o número de consumidores atendidos, a redução das perdas, a manutenção dos níveis de tensão e carregamento do sistema em patamares adequados, a redução do número de manobras das chaves, dentre outros. Diversos métodos vêm sendo desenvolvidos a fim de determinar a configuração ótima para o sistema. Entretanto, diversos métodos propostos não consideram indicadores de continuidade do sistema como, por exemplo, a frequência de interrupção individual por unidade consumidora ou ponto de conexão (FIC), os quais podem acarretar multas pelo lado da distribuidora caso seus limites não sejam respeitados. Em outros casos, mesmo incluindo indicadores de continuidade tais como o FIC, os métodos propostos não conseguem evitar o desligamento repetido de unidades consumidores em caso de contingências sucessivas. Desta forma, é apresentada neste trabalho uma nova metodologia para reconfiguração das redes de...
Anais do 14º Simpósio Brasileiro de Automação Inteligente
This paperwork proposes a methodology to determine a model of distributed generation of electric ... more This paperwork proposes a methodology to determine a model of distributed generation of electric energy from photovoltaic panels, determining the optimal allocation of these generators in an electric energy distribution network, using technical parameters and calculating the installation cost of those panels. The methodology makes use of the photovoltaic generation profile in the summer season and is based on the load curve of low voltage residential consumers. The optimization of the location of the distributed generation units aims to minimize the daily losses of active power and the installation costs of the generators connected to the network. The optimization problem also provides for the allocation of battery banks with the distributed generators, in order to manage the active power of the network and, consequently, to improve the voltage profile and minimize the electrical losses. The optimization solution is obtained through a Genetic Algorithm, which receives as input the daily data of the active power of the solar generators and the load demand to search for better solutions to the problem. To validate the proposed solution a test was carried out on a 78-bar radial feeder, resulting in daily losses of active power and voltage profiles. Resumo: Propõe-se uma metodologia para determinar um modelo de geração distribuída de energia elétrica a partir de painéis fotovoltaicos, determinando a alocação ótima desses geradores em uma rede de distribuição de energia elétrica, utilizando parâmetros técnicos e calculando o custo de instalação desses painéis. A metodologia faz uso do perfil de geração fotovoltaica na temporada de verão e é baseada na curva de carga de consumidores residenciais de baixa tensão. A otimização da localização das unidades de geração distribuída visa minimizar as perdas diárias de energia ativa e os custos de instalação dos geradores conectados à rede. O problema de otimização também prevê a alocação de bancos de baterias em concomitância com a geração distribuída, a fim de gerenciar a potência ativa da rede e, consequentemente, melhorar o perfil de tensão e minimizar as perdas elétricas. A solução de otimização é obtida através de um Algoritmo Genético, que recebe como entrada os dados diários da potência ativa dos geradores solares e a demanda de carga para buscar melhores soluções para o problema. Para validar a solução proposta, foi realizado um teste em um alimentador radial de 78 barras, resultando em perdas diárias de perfis de tensão e potência ativa.
International Journal of Electrical Engineering Education
The interest in optimization problems involving distributed generation units has grown among unde... more The interest in optimization problems involving distributed generation units has grown among undergraduate and graduate students since distributed generation unit connections have been encouraged around the world, requiring efficient power system analysis tools to solve them. The available open access tools are commonly focused on transmission network analysis. On the other hand, commercial tools adapted to radial networks do not allow the students to follow the intermediary calculations and learn with them. In many cases, the students have to develop their own computational tools, which is a time-consuming activity. This paper aims to fill the gap encountered by undergraduate and graduate students when they are performing their optimization problems involving distributed generation units, presenting the advantages of a new power flow tool focused on radial electrical distribution networks with high levels of unbalanced loads which require a three-phase power flow tool to be analyzed. The use of the proposed tool allows the students focus on their research, reducing the time spent on programming, and learning about power flow analysis applied to radial networks.
International Journal of Hydrogen Energy
Advances in Renewable Energies and Power Technologies
Electric Power Systems Research
Renewable Energy and Power Quality Journal, 2013
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015
2020 11th International Renewable Energy Congress (IREC), 2020
The development of a thermochemical and electrical model that enables to provide of the solid oxi... more The development of a thermochemical and electrical model that enables to provide of the solid oxide fuel cell operation in different conditions is presented in this paper. The validation is carried out by comparing the proposed model with results in the literature for several SOFCs. This model allows to reproduce the expected values of SOFC key variables to be quickly obtain without requiring complex software, as illustrated for a case study.
Raquel Frizera Vassallo∗ Lucas Frizera Encarnaçao∗ José Santos-Victor Hans Jörg Schneebeli∗ ∗UF... more Raquel Frizera Vassallo∗ Lucas Frizera Encarnaçao∗ José Santos-Victor Hans Jörg Schneebeli∗ ∗UFES - Universidade Federal do Espırito Santo Av. Fernando Ferrari s/n - Dep. Engenharia Elétrica, Vitória, ES, Brasil ... ISR/IST - Instituto de Superior Técnico ...
This paper proposes a predictive current control (PCC) strategy with a field orientation applied ... more This paper proposes a predictive current control (PCC) strategy with a field orientation applied on a three-level neutral point clamped (NPC) inverter to drive a three-phase induction motor. It was used the optimal switching vector (OSV) strategy, which is most suitable for power electronics. The field orientation, along with a rotor flux estimation, made it possible to implement a control loop measuring only stator voltage, stator current and rotor speed. The simulation results showed that the average estimated rotor flux error was 0.03%, the total harmonic distortion (THD) for the stator current was 9.29%, and the average stator current error was 5.82%. The proposed model proved to be a viable option to industrial plants, especially when compared with classical controllers.
Energies
This paper proposes a new cascaded multilevel converter topology based on three-phase H bridge ce... more This paper proposes a new cascaded multilevel converter topology based on three-phase H bridge cells with a common DC-link structure. The proposed multilevel converter topology main advantages, compared with literature renowned multilevel converters topologies, are discussed in the paper, such as modularity, construction, implementation cost, and DC voltage ripple mitigation. Despite presenting an elementary structure and easy implementation, the use of classic PWM switching strategies is not feasible for this topology, causing the appearance of several short-circuit states between its capacitors. Thus, a graph theory algorithm combined with a model predictive control is also proposed in this work to identify and avoid the new cascaded multilevel converter short-circuit switching states and, concomitantly, guaranteeing the converter output power quality. In order to validate the presented topology applicability, a low voltage synchronous static compensators (STATCOM) with an optimal...
Electronics
Recently, many non-conventional three-phase inverters, topologies for green energy source grid-co... more Recently, many non-conventional three-phase inverters, topologies for green energy source grid-connection systems, and electric drives have been proposed. Simplifying the inverter circuit is crucial to analyze and solve their models in order to design them. The main goal of the study is centered on obtaining a single-phase equivalent circuit and space state model from non-conventional three-phase inverters based on bidirectional direct current–direct current (DC–DC) Buck-Boost topology using isolated gate bipolar transistors (IGBT). From just one phase of the three-phase inverter, the single-phase equivalent circuit was obtained by means of Kirchhoff’s laws. The equivalent circuit operation steps were presented in order to obtain the space state model. Finally, the equivalent circuit was simulated, and experimental results with a 200 W three-phase inverter feeding a resistive, inductive, and capacitive loads were performed to confirm the theoretical and simulation analyses. The resu...
Eletrônica de Potência
Resumo-Este artigo apresenta uma proposta de modulação híbrida, combinando a modulação em degrau ... more Resumo-Este artigo apresenta uma proposta de modulação híbrida, combinando a modulação em degrau convencional com a modulação PWM (Pulse Width Modulation) descontínua, aplicada aos conversores multiníveis em cascata assimétricos. O desempenho da modulação híbrida proposta neste trabalho será comparada com duas estratégias híbridas convencionais por meio de resultados de simulação e experimentais. O conversor multinível implementado é composto por três inversores monofásicos, em ponte completa, por fase. Por fim, um compensador síncrono estático aplicado a redes de distribuição de média tensão (DSTATCOM) é implementado no intuito de validar experimentalmente a estratégia de modulação proposta.
Brazilian Journal of Development
International Journal of Hydrogen Energy
Revista Ifes Ciência
O processo de reconfiguração da rede elétrica visa atender a critérios técnico-econômicos como o ... more O processo de reconfiguração da rede elétrica visa atender a critérios técnico-econômicos como o número de consumidores atendidos, a redução das perdas, a manutenção dos níveis de tensão e carregamento do sistema em patamares adequados, a redução do número de manobras das chaves, dentre outros. Diversos métodos vêm sendo desenvolvidos a fim de determinar a configuração ótima para o sistema. Entretanto, diversos métodos propostos não consideram indicadores de continuidade do sistema como, por exemplo, a frequência de interrupção individual por unidade consumidora ou ponto de conexão (FIC), os quais podem acarretar multas pelo lado da distribuidora caso seus limites não sejam respeitados. Em outros casos, mesmo incluindo indicadores de continuidade tais como o FIC, os métodos propostos não conseguem evitar o desligamento repetido de unidades consumidores em caso de contingências sucessivas. Desta forma, é apresentada neste trabalho uma nova metodologia para reconfiguração das redes de...
Anais do 14º Simpósio Brasileiro de Automação Inteligente
This paperwork proposes a methodology to determine a model of distributed generation of electric ... more This paperwork proposes a methodology to determine a model of distributed generation of electric energy from photovoltaic panels, determining the optimal allocation of these generators in an electric energy distribution network, using technical parameters and calculating the installation cost of those panels. The methodology makes use of the photovoltaic generation profile in the summer season and is based on the load curve of low voltage residential consumers. The optimization of the location of the distributed generation units aims to minimize the daily losses of active power and the installation costs of the generators connected to the network. The optimization problem also provides for the allocation of battery banks with the distributed generators, in order to manage the active power of the network and, consequently, to improve the voltage profile and minimize the electrical losses. The optimization solution is obtained through a Genetic Algorithm, which receives as input the daily data of the active power of the solar generators and the load demand to search for better solutions to the problem. To validate the proposed solution a test was carried out on a 78-bar radial feeder, resulting in daily losses of active power and voltage profiles. Resumo: Propõe-se uma metodologia para determinar um modelo de geração distribuída de energia elétrica a partir de painéis fotovoltaicos, determinando a alocação ótima desses geradores em uma rede de distribuição de energia elétrica, utilizando parâmetros técnicos e calculando o custo de instalação desses painéis. A metodologia faz uso do perfil de geração fotovoltaica na temporada de verão e é baseada na curva de carga de consumidores residenciais de baixa tensão. A otimização da localização das unidades de geração distribuída visa minimizar as perdas diárias de energia ativa e os custos de instalação dos geradores conectados à rede. O problema de otimização também prevê a alocação de bancos de baterias em concomitância com a geração distribuída, a fim de gerenciar a potência ativa da rede e, consequentemente, melhorar o perfil de tensão e minimizar as perdas elétricas. A solução de otimização é obtida através de um Algoritmo Genético, que recebe como entrada os dados diários da potência ativa dos geradores solares e a demanda de carga para buscar melhores soluções para o problema. Para validar a solução proposta, foi realizado um teste em um alimentador radial de 78 barras, resultando em perdas diárias de perfis de tensão e potência ativa.
International Journal of Electrical Engineering Education
The interest in optimization problems involving distributed generation units has grown among unde... more The interest in optimization problems involving distributed generation units has grown among undergraduate and graduate students since distributed generation unit connections have been encouraged around the world, requiring efficient power system analysis tools to solve them. The available open access tools are commonly focused on transmission network analysis. On the other hand, commercial tools adapted to radial networks do not allow the students to follow the intermediary calculations and learn with them. In many cases, the students have to develop their own computational tools, which is a time-consuming activity. This paper aims to fill the gap encountered by undergraduate and graduate students when they are performing their optimization problems involving distributed generation units, presenting the advantages of a new power flow tool focused on radial electrical distribution networks with high levels of unbalanced loads which require a three-phase power flow tool to be analyzed. The use of the proposed tool allows the students focus on their research, reducing the time spent on programming, and learning about power flow analysis applied to radial networks.
International Journal of Hydrogen Energy
Advances in Renewable Energies and Power Technologies
Electric Power Systems Research
Renewable Energy and Power Quality Journal, 2013
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015
Anais do VI Simpósio Brasileiro de Sistemas Elétricos, 2015