Papers by Raimundo F Sampaio
Aspectos gerais; Comportamento dos machos estereis nas condicoes do Submedio do Vale do Sao Franc... more Aspectos gerais; Comportamento dos machos estereis nas condicoes do Submedio do Vale do Sao Francisco.
Encontros Universitários da UFC, Mar 29, 2017
Nos últimos anos tem crescido a inserção de geração distribuída (GD) nas redes de distribuição de... more Nos últimos anos tem crescido a inserção de geração distribuída (GD) nas redes de distribuição de energia elétrica. Uma forma efetiva de fazer uso dos benefícios das GDs é adotar a estratégia de agregá-las sob controle, formando um subsistema denominado de microrrede. Este trabalho apresenta uma abordagem de controle descentralizado aplicado a uma microrrede composta por duas unidades de geração fotovoltaica, de 10 kW e 5 kW, e uma eólica, de 15 kW. Para o controle da microrrede foi usada a técnica de controle por inclinação que permite o compartilhamento adequado de potência das fontes, sem troca de informação entre elas, para manutenção do balanço de potência da microrrede. As simulações da microrrede foram realizadas no software PSCAD. Os resultados mostraram uma atuação satisfatória do controle por inclinação, proporcionando uma correta coordenação entre as unidades de geração distribuída no sentido de compartilhar a carga corretamente, de acordo com a capacidade de cada fonte.
Sistemas De Controle Distribuído Aplicado a Microrredes
Congresso Brasileiro de Automática - CBA, 2019
In the past few years, the presence of distributed generation (DG) in the power distribution sy... more In the past few years, the presence of distributed generation (DG) in the power distribution systems have greatly evolved. An effective way of taking advantage of the DGs benefits is to aggregate them and its loads in a subsystem called microgrid. This paper presents a primary and secondary distributed control approach applied to a microgrid that encompasses a three-phase photovoltaic generation unit of 5 kW, a full converter wind turbine system of 15 kW and a gas micro-turbine with 10 kW. The well-established droop control technique was applied for the microgrid primary control. The restoration of the frequency and voltage deviation from the nominal value was performed by a secondary control strategy. The multiagent based secondary control was developed using an open source platform named PADE (Python Agent Development Environment). The microgrid simulations were performed using PSCAD software that provides a management and control library, written in Python 3 programming language, enabling the integration with the PADE platform. The performance of the droop control was observed through the appropriate power sharing of the microgrid sources. The communication between PSCAD and PADE was carried out, enabling the reading of simulation data and the sending of commands, in real time. Keywords Distributed Generation, Droop Control, Microgrid, Multiagent System, Renewable Energy Resumo Nos últimos anos, a presença de geração distribuída (DG) nos sistemas de distribuição de energia elétrica cresceu bastante. Uma forma eficaz de aproveitar os benefícios das DGs é agregá-las com suas cargas em um subsistema chamado microrrede. Este artigo apresenta uma abordagem de controle distribuída primária e secundária aplicada a uma microrrede que engloba uma unidade de geração fotovoltaica trifásica de 5 kW, um sistema de turbina eólica com conversor pleno de 15 kW e uma microturbina a gás de 10 kW. A bem estabelecida técnica de controle por inclinação foi aplicada para o controle primário da microrrede. O restabelecimento dos desvios de frequência e tensão do valor nominal foi realizado por uma estratégia de controle secundária. O controle secundário baseado em multiagentes foi desenvolvido usando uma plataforma de código aberto chamada PADE (Python Agent Development Environment). As simulações da microrreda foram realizadas utilizando o software PSCAD, que fornece uma biblioteca de gerenciamento e controle, escrita em linguagem de programação Python 3, possibilitando a integração com a plataforma PADE. O desempenho do controle por inclinação foi observado através do compartilhamento apropriado de potência das fontes da microrrede. A comunicação entre o PSCAD e o PADE foi realizada, possibilitando a leitura de dados da simulação e o envio de comandos, em tempo real. Palavras-chave Controle por Inclinação, Energia Renovável, Geração Distribuída, Microrrede, Sistema Multiagente
Encontros Universitários da UFC, Mar 29, 2017
Design and analysis of a cost-effective back-to-back converter for a low voltage doubly fed induction generator
Distributed generation systems based on renewable energies, such as solar and wind energy sources... more Distributed generation systems based on renewable energies, such as solar and wind energy sources, are nowadays one of the most promising ways to meet the power demand increase, the customer interests to generate electricity and the environmental issues. The scattering of small solar and wind generators should be promoted as a way to reduce the impact of the non-programmable production of these sorts of sources. For that, cost-effective solutions are sought to step up the use of these sources. This paper deals with the design and performance analysis of a cost-effective converter applied to control the power output of a small double fed induction generator for wind turbines connected to a low voltage network. A four-quadrant converter, suitable for low voltage and smart grids applications, is proposed and its characteristics are illustrated.
Revista de Informática Teórica e Aplicada, Apr 27, 2020
Resumo: This paper describes the integration process between two tools in order to perform co-sim... more Resumo: This paper describes the integration process between two tools in order to perform co-simulation for representation and analysis of dynamic environments in the context of smart grids. The integrated tools are Mosaik, a software to co-simulation management, and PADE, a software to multi-agent systems development. As a study case for demonstrate the integration, a scenary was utilized composed of a low voltage electricity distribution grid with 37 load bus, 20 photo-voltaic distributed generations, randomly connected to load bus, as well as, 20 PADE agents associated to distributed generation, modeling the behavior of electricity storage systems. The simulation results show the integration happening and demonstrate how useful is to model the dynamics of distributed electric resources with multi-agent systems.
An adaptive protection system for distribution network with distributed generation
Distribution networks have increased reliability and security with the penetration of distributed... more Distribution networks have increased reliability and security with the penetration of distributed generation and the application of automation functions that imply in topological reconfiguration. These changes however have effect on the protection systems and bring challenges to the planning and operation of the distribution networks. Therefore, this work proposes an adaptive protection system (APS) that aims to mitigate the impacts of distributed generation and topological reconfiguration in the protection system. The proposed system is activated by topological change, the switch on/off of generation units and change in the magnitude of the feeder currents. The APS is able to change the relays setting groups as well as to calculate and send to the relays a new setting. The application tool was developed in MATLAB and communicates with relays via Telnet protocol. Tests have been performed using a commercial relay and a computational model of a real distribution network.
Energies, Feb 27, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Latin American Journal of Development, Jul 18, 2023
Application of Multi-objective Evolutionary Algorithms in automatic restoration of radial power distribution systems
arXiv (Cornell University), Aug 21, 2014
This book chapter reviews signal detection and parameter estimation techniques for multiuser mult... more This book chapter reviews signal detection and parameter estimation techniques for multiuser multiple-antenna wireless systems with a very large number of antennas, known as massive multi-input multi-output (MIMO) systems. We consider both centralized antenna systems (CAS) and distributed antenna systems (DAS) architectures in which a large number of antenna elements are employed and focus on the uplink of a mobile cellular system. In particular, we focus on receive processing techniques that include signal detection and parameter estimation problems and discuss the specific needs of massive MIMO systems. Simulation results illustrate the performance of detection and estimation algorithms under several scenarios of interest. Key problems are discussed and future trends in massive MIMO systems are pointed out.
Distributed control based on the consensus algorithm for the efficient charging of electric vehicles
Electric Power Systems Research, May 1, 2023
Renewable & Sustainable Energy Reviews, Jul 1, 2016
Microgrids are presently receiving great attention and are considered the future trend for power ... more Microgrids are presently receiving great attention and are considered the future trend for power distribution systems. This paper presents the control and management of a microgrid with distributed energy resources connected to a single bus. The microgrid management system uses a centralized and heuristic approach that considers the stochastic production of a photovoltaic power source, the use of a fuel cell, the state of charge of batteries, the variable load profile, and the flag-color of electricity tariff. The goal of the control and management system is the reliable and economic using of energy resources and their integration to power distribution systems while preserving the power quality. The responses regarding the control system of the power inverters connected to the distributed energy resources in the microgrid are evaluated during grid connection, standalone operation, and transition between the aforementioned operating modes. Simulation results prove that the control and management strategy is suitable in all operating conditions of the microgrid. The whole system composed of distributed energy resources, power electronic systems, and their respective control approaches that allow power management were developed in PSCAD/EMTDC simulation program.
Anais do XXII Simpósio Brasileiro de Telecomunicações
Resumo-Este artigo apresenta um processador espáciotemporal de posto reduzido para supressão adap... more Resumo-Este artigo apresenta um processador espáciotemporal de posto reduzido para supressão adaptativa de interferência em sistemas DS-CDMA baseada em filtros FIR interpolados e onde os interpoladores são também feitos adaptativos. Um algoritmo de projeções afins (AP) e um algoritmo recursive least squares (RLS) são desenvolvidos para adaptar os parâmetros do receptor de posto reduzido e do interpolador. Um receptor linear utilizando a estrutura proposta para suprimir interferência de múltiplo acesso (MAI) e interferência intersimbólica (ISI) em um enlace reversoé investigado. Palavras-Chave-DS-CDMA, Processamento espáciotemporal, detecção multiusuário, receptores de posto reduzido, algoritmos adaptativos.
arXiv (Cornell University), Nov 17, 2016
Massive multiple-input multiple-output (MIMO) systems are strong candidates for future fifth gene... more Massive multiple-input multiple-output (MIMO) systems are strong candidates for future fifth generation (5G) heterogeneous cellular networks. For 5G, a network densification with a high number of different classes of users and data service requirements is expected. Such a large number of connected devices needs to be separated in order to allow the detection of the transmitted signals according to different data requirements. In this paper, a decoupled signal detection (DSD) technique which allows the separation of the uplink signals, for each user class, at the base station (BS) is proposed for massive MIMO systems. A mathematical signal model for massive MIMO systems with centralized and distributed antennas in heterogeneous networks is also developed. The performance of the proposed DSD algorithm is evaluated and compared with existing detection schemes in a realistic scenario with distributed antennas. A sum-rate analysis and a computational cost study for DSD are also presented. Simulation results show an excellent performance of the proposed DSD algorithm when combined with linear and successive interference cancellation detection techniques.
Anais do XXV Simpósio Brasileiro de Telecomunicações, 2007
Resumo-Este trabalho investiga o impacto de estimativa de canal melhorada no desempenho dos siste... more Resumo-Este trabalho investiga o impacto de estimativa de canal melhorada no desempenho dos sistemas MC-CDMA e MC-DS-CDMA, com intevalo de guarda ZP (Zero Padding), no enlace direto. Nós apresentamos modificações nas estimativas de canal MMSE assistidos para os sistemas. Três versões de estimadores são apresentadas. A primeira estratégia consiste em aplicar uma matriz de projeção na estimativa inicial da resposta em freqüência do equivalente discreto do canal com o intuito de eliminar componentes indesejáveis do ruído. A segunda estratégia aplica uma restrição inicial na solução MMSE, para obter a estimativa da resposta ao impulso do canal e, a seguir, convertê-la para o domínio da freqüência. Os resultados obtidos, por simulação em computador, são apresentados em termos de erro médio quadrático (MSE) e taxa de erro de bits (BER). O desempenho dos sistemas utilizando a estimativa com restrição inicial mostra-se superior para os dois sitemas considerados.
Anais do XXVI Simpósio Brasileiro de Telecomunicações, 2008
Resumo-Este trabalho investiga o problema da estimação cega de canal em sistemas MC DS CDMA ZP (M... more Resumo-Este trabalho investiga o problema da estimação cega de canal em sistemas MC DS CDMA ZP (Multi Carrier Direct Sequence Code Division Multiple Access Zero Padded). Usando somente o código de espalhamento do usuário de interesse, o método proposto, baseado no método das potências, estima a resposta ao impulso do canal multipercurso a partir do sinal recebido. Análises de desempenho simulado da taxa de erro de bit e de erro médio quadrático demonstraram que para moderada razão sinal ruído o método apresentado tem desempenho comparável aos tradicionais métodos de SVD mas com menor complexidade computacional.
Detecção Multiusuário Ótima Por Grupos Em Sistemas DS/Cdma M-PSK Com Codificação Convolucional
Simulation of inrush currents in a wind power plant using ATP draw
2018 Simposio Brasileiro de Sistemas Eletricos (SBSE), 2018
The incresing participation of the wind generation in the energetic matrix brings new challenges ... more The incresing participation of the wind generation in the energetic matrix brings new challenges to the electric power system. The system's reliability and stability must be sustained against the characteristcs inherent to this type of generation. The current paper presents a simulation in ATP Draw of a wind farm of 130 MVA of rated power which has 2 power transformers at the collector substation and 77 step-up transformers in each turbine output. The aspects of the inrush current at the wind farm energization were analysed, such as wave form and maximum rms value. It was verified that the common used topology in wind power plants brings, due to the large amount of transformers, a high inrush current at the conection point. This current shall be considered at the operation and protection of the farm.
Uploads
Papers by Raimundo F Sampaio