Navegando por Assunto "Fluxo de carga"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Comparação entre métodos de fluxo de carga para redes de distribuição ativas
(Universidade Federal do Pará, 2018-12-04) AMARAL, Lucas Felipe; VIEIRA, João Paulo Abreu; http://lattes.cnpq.br/8188999223769913
This dissertation presents a comparative study of load flow methods for analysis of active distribution networks. The proposed study takes into account the changes already faced by distribution systems, such as a high penetration of distributed generation (DG), while considering the typical characteristics of distribution networks, as the high R/X ratios. These characteristics impose difficulties on the performance of both backward-forward sweep and decoupled-based power flow methods. On the other hand, modified algorithms based on the decoupled method, such axis rotation fast decoupled and fast decoupled via pu normalization, can be efficiently applied to distribution system analysis. Thereby, a comparison of performance in terms of number of iterations and computational effort is carry out between the following methods: Newton-Raphson, Current Summation, Axis Rotation Fast Decoupled and Fast Decoupled via Complex pu. Normalization. The performance of each method is analyzed for different DG penetration levels, DG modelled as PQ and PV buses, and different R/X ratios. In addition, the influence of the base angle of both decoupled methods on the number of iterations was analyzed. The methods were tested in four distribution systems: 2-bus system, IEEE 69-bus system, 476-bus system and 1080-bus system.
Acesso aberto (Open Access)
Estratégias de paralelismo com GPGPU para otimização do processamento do cálculo do fluxo de carga em sistemas elétricos de potência
(Universidade Federal do Pará, 2017-03-23) ARAÚJO, Igor Meireles de; SANTANA, Ádamo Lima de; http://lattes.cnpq.br/4073088744952858
The load flow calculation provides fundamental information for an electric power system. However, the load flow can only be carried out in the steady state, in the event of a system suffering any change, by variation in the loads or modifications of the control equipment, this calculation is necessary to be redone. Because of this need, frequently have to perform the load flow, a research has begun to optimize the time needed for this task. A General-Purpose Graphic Processing Unit (GPGPU) as a cost-effective alternative to parallel architecture runs, which has a GPU not only for graphics purposes but also for general purposes. Several works were taken for the use of GPGPU in load flow calculations, there is no consensus on the content of the material, being in charge of each one of the work of its own method, making it difficult to use the architecture for an implementation of calculations, both for academic purposes and for the market. Due to the lack of consensus and differences found in the work, this dissertation aims to analyze the steps of the load flow, identifying which is more suitable to parallelize in GPGPU in order to perform simultaneous load flow calculations and reduces the time required for the processing, an efficient strategy for large scale systems in the market and not academic environment, facilitate the replication for future works using metaheuristics for optimization of power electrical systems.
Acesso aberto (Open Access)
Metodologia para cálculo de perdas técnicas e não técnicas de alimentadores de distribuição via estudos de fluxo de carga pelo Método Somatório de Potência Modificado
(Universidade Federal do Pará, 2017-04-04) OLIVEIRA, Rafael Cavalcante de; NUNES, Marcus Vinicius Alves; http://lattes.cnpq.br/9533143193581447; BEZERRA, Ubiratan Holanda; http://lattes.cnpq.br/6542769654042813
Fundamental to economic activity the electric energy sector in Brazil is regulated by the relevant agency, ANEEL. Which regulates and supervises the production, transmission / distribution and commercialization of electric energy in accordance with the policies of the federal government. Among other functions, ANEEL defines the tariff values to be charged by the concessionaires through tools such as Tariff Reviews. The non-technical losses (or commercial losses) of the electric power company are part of the energy tariff composition, being passed on to the final consumer, within a pre-established limit. Therefore reducing commercial losses is a fundamental issue for energy distributors, as it increases the profitability of the company and decreases energy costs to the end user. This work, being the result of a research project carried out in partnership between the power distribution utility of the state of Pará, CELPA, and the Federal University of Pará, UFPA, aims to develop a new methodology in the scope of operational planning, including technical loss information and techniques in load flow studies using modified Power Summation Method. Initially, an analysis of the scenario of the Brazilian electric sector is presented, with emphasis on the frauds and thefts of energy, considering the impacts of this reality from the financial point of view for both the energy concessionaires and the clients, as well as the impacts on the services to these consumers. Afterwards a new methodology, able to more assertively determine the actual operating state of the distribution network is showed, taking into account the commercial losses of energy, together with real measurements of active and reactive power injected in the feeders, in the point of common coupling with the substation. The method developed using both an IEEE 13-bus test feeder and an urban feeder of the Belém metropolitan network belonging to the Pará power utility CELPA, is applied and the results obtained are then presented and analyzed.