Navegando por Assunto "Capacidade de hospedagem"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Estimativa da capacidade de hospedagem de geração distribuída em redes de distribuíção via algoritmos genéticos
(Universidade Federal do Pará, 2019-03-29) SOUSA, Alana Lima de; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
The use of distributed generation (DG) and distributed energy sources (DER) close to the consumer centers has been gaining prominence around the world. The high penetration level of DG will shift the operation paradigm of electric energy systems, affecting power quality delivered to consumers. The active power injection from DG can cause several consequences to distribution systems, being overvoltage issue the most impacting of them. The reverse power flow from the DG units can cause voltage rise issue on distribution networks and consequently the DG shutdown. During unity power factor (pf) operation of DG, the distribution operators control overvoltage by active power curtailment. In this scenario emerges the GD hosting capacity concept, which consists of estimating the maximum power injected by GD without compromising voltage quality of the distribution system. This dissertation estimates the DG hosting capacity on MV distribution systems using genetic algorithms, considering as main limiting factor the overvoltage issue. Performance tests were performed on IEEE 33-bus and IEEE 69-bus systems.
Acesso aberto (Open Access)
Formulação analítica para estudo de redes de distribuição ativas considerando a presença de reguladores de tensão
(Universidade Federal do Pará, 2019-09-26) BRITO, Hugo Rodrigues de; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
Step voltage regulators (SVRs) located at medium-voltage radial feeders are often part of many strategies to mitigate interconnection impacts of distributed generation (DG) units. However, conventional methods for rapid analysis of characteristic parameters of active distribution networks do not usually factor the effect of SVR tap operations in their calculations. This dissertation proposes a novel analytical formulation for the assessment of the influence of such devices, based on mathematical modification of traditional expressions found in the literature. The developed theoretical framework concerns voltage variation along the feeder, requirement of reactive power, electrical losses and DG hosting capacity. The proposed approach is validated via comparative studies conducted in a simple test-system, as well as in a long 34.5 kV rural feeder that contains two cascaded SVRs along with a high penetration DG at its far end. The Open Distribution Simulator Software (OpenDSS) is used for modelling, traditional load flow simulations and quasi-static time series analyses. Results show the merits of the developed formulation in correctly estimating active distribution networks’ parameters in the presence of SVRs, which marks an improvement over conventional tools for DG integration preliminary studies.
Acesso aberto (Open Access)
Influência da microgeração fotovoltaica no perfil de demanda e seus impactos na geração de harmônicos na rede
(Universidade Federal do Pará, 2024-02-29) PARIJÓS JÚNIOR, Ivan Ruy de; GALHARDO, Marcos André Barros; http://lattes.cnpq.br/6672470707462259; https://orcid.org/0000-0001-6248-5187; MACÊDO, Wilson Negrão; http://lattes.cnpq.br/3386249951714088; https://orcid.org/0000-0002-6097-8620
This study addresses the integration of photovoltaic generation into the electrical grid, emphasizing the necessity to consider changes in the load profile of consumer units and the presence of harmonic components in the grid current, originating from loads with nonlinear characteristics and photovoltaic inverters. Various percentages of inverter loading were considered in the study to evaluate their impact on grid operation due to varying levels of harmonic components. The research comprises an experimental phase, a phase dedicated to developing models of inverter output currents, and a simulation phase. In the experimental phase, data on the output currents of three photovoltaic inverters were collected. These data were then utilized in the development of models of inverter output currents for theoretical analyses, evaluating factors influencing the power quality of the grid. Subsequently, these models were applied in the simulation phase. The grids evaluated in the simulation phase include a standard IEEE system and a real isolated grid, located in the Northern region of Brazil. Comparative assessments of network hosting capacity were conducted using two different strategies. The first strategy employed conventional power flow analysis, while the second strategy applied the developed models. It is observed that the operation of different inverters within the same grid may contribute to harmonic attenuation. Furthermore, it is highlighted that the presence of grid-connected photovoltaic systems, operating in conjunction with loads, results in an apparent increase in harmonic current content in the grid, whereas, in reality, there is a reduction in the circulating fundamental component. The obtained results indicate that conventional power flow studies may underestimate the intensity of circulating currents in the grid by neglecting the presence of harmonic components. This study innovates by assessing the circulation of harmonic components in the grid due to the combined operation of photovoltaic generation and load, considering various inverter loading scenarios and the effects of consumer electrical current, including the phase of harmonic components.