Navegando por Assunto "Microgrid"

Agora exibindo 1 - 4 de 4

Acesso aberto (Open Access)
Modelagem e simulação da operação de sistemas de geração com fontes renováveis de energia suprindo minirrede de distribuição
(Universidade Federal do Pará, 2018-01-19) FERREIRA, Andreza Cardoso; GALHARDO, Marcos André Barros; http://lattes.cnpq.br/6672470707462259; PINHO, João Tavares; http://lattes.cnpq.br/0847897516772421
This work is about the development of computational models in Simulink/Matlab workspace, that simulate the operation in islanded or grid connected mode of electrical energy distribution microgrid with hybrid resources, belonging to the Group of Studies and Development of Energy Alternatives (Grupo de Estudos e Desenvolvimento de Alternativas Energéticas - GEDAE) of Universidade Federal do Pará (UFPA), in the Campus of Belém. This paper also describes the hybrid systems and its components (generation systems, power conditioners, microgrid and proposed loads), also the mathematical models, presenting the equations of components applied to dynamic studies. Then the component models that compose the system are validated and analyzed based on the experimental data. It also presents the integration of the proposed models of the hybrid system, simulating three different strategies or modes of operation as a case study. The developed model has the function of helping these studies, simplifying the analysis and providing different possibilities of simulations in short processing time. The principal aim of the work is to make available a computational model able to simulate in detail the behavior of a hybrid system in connected or isolated of conventional power grid operation conditions.
Acesso aberto (Open Access)
Projeto de controlador baseado em inequações matriciais lineares aplicado a um sistema multiconversor sujeito à incertezas paramétricas
(Universidade Federal do Pará, 2024-08-23) SILVA JUNIOR, Carlos Roozenbergh Porto da; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608
Conversion systems are critically important devices in electrical systems across various environments, especially in modern times, as multiple components with different voltage levels and sources are interconnected within a single system. Consequently, dynamic study methods of this network are examined using approaches that simplify the network based on speed modes and switching of other conversion systems, wherein fast systems are simplified to constant power loads (CPL). This method evaluates the network’s stability conditions. The study reveals that CPLs act as negative incremental resistances, and when analyzed through a linear model, it is observed that such loads reduce system damping, thereby decreasing stability margins and potentially rendering the system unstable. Additionally, uncertainties in the physical components of the circuit further affect the stability and performance of microgrids. Hence, designing regulators to mitigate oscillations caused by these effects becomes crucial to ensure the proper performance of these systems.In this work, a robust controller is designed to handle uncertainties and attenuate oscillations in the presence of constant power loads. This controller is implemented in a microgrid composed of two cascaded DC-DC buck converters, one of which is modeled as a CPL. The system model is utilized for both stability analysis and robust controller design in state space, where the compensator synthesis is structured in the form of a linear matrix inequality, solved using system optimization tools. The controller’s results are compared with another controller based on pole placement in both linear and nonlinear switched models, within the Matlab/Simulink simulation platform. Transient response and control signals are evaluated graphically and through performance indices under various operating conditions, including load disturbances and system parameter variations.
Acesso aberto (Open Access)
Regulação de tensão e frequência em micro-redes ilhadas com veículos elétricos e geração distribuída utilizando otimização por enxame de partículas
(Universidade Federal do Pará, 2019-08-16) SILVA, Rodrigo Veiga da; AFFONSO, Carolina de Mattos; http://lattes.cnpq.br/2228901515752720
This workpresents afrequency and voltage control implementation for a droop-regulated islanded microgrid through Direct Backward Forward Sweep Load-Flow Method (DBFS) modeled as a particle swarm optimization (PSO) problem. The PSO –allied with the Vehicle-to-Grid (V2G) technology of electric vehicles–controls the microgrid droop features to improve its steady-state frequency and voltage. Thus, working as a secondary control action. Simulations are performed in a 33-bus distribution system with distributed generators and electric vehicles operating over a 24-hour period.Theproposal of secondary control, based on PSO, proved to be versatile and efficient in face of load and generation variations.
Acesso aberto (Open Access)
Técnicas de controle robusto baseadas em resposta em frequência e via alocação de polos intervalar para sistemas com incertezas paramétricas aplicadas ao problema de regulação de tensão em conversores de potência.
(Universidade Federal do Pará, 2022-05-12) CARDOZO, Luise Ferreira; BARRA JUNIOR, Walter; http://lattes.cnpq.br/0492699174212608
Microgrids are a form of distribution system, which belong to the broad concept of smart grids. Multiconverter or multilevel systems are nothing more than DC microgrids composed of several power converters connected in cascade and/or in parallel. In this way, the multiconverter system described in this thesis has a DC - DC converter in the Buck topology, which is used as a source of direct voltage for the main bus of the microgrid, being an element of fundamental importance and whose voltage control is essential, because electronic loads are sensitive to voltage deviations. In order to control the voltage on the DC bus, the system is first modeled using the recursive least squares method, at which time the parametric variations are obtained forming a more comprehensive model called the interval transfer function, which is represented graphically by the extreme set. In a second moment, two robust controllers are developed, one through the extreme stability margins of the model culminating in a PI controller based on frequency response, and the other through an interval pole allocation control project in PID format. The robust performance of the controllers is evaluated through computational simulation, experimentally in the multiconverter system and, finally, using a quantitative analysis through performance indices.