Navegando por Assunto "Campanha de medição"

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Acesso aberto (Open Access)
Impactos na qualidade da energia elétrica provenientes do rápido crescimento da demanda no Sudeste do Estado do Pará
(Universidade Federal do Pará, 2012-03-15) ESTEVES, Eduardo Augusto Cardoso; BEZERRA, Ubiratan Holanda; http://lattes.cnpq.br/6542769654042813; TOSTES, Maria Emília de Lima; http://lattes.cnpq.br/4197618044519148
In the recent years, the social and economical development in the Southeast of the State of Pará has been mainly caused by the exploitation and processing of mineral industries, which added to the population growth, has generated a high increase in the demand of electric energy and consumption due to the increasing installation of new industrial, commercial, residential and rural single-phase charges. This global increase is impacting directly the performance of distribution of electric utility, which can be expressed by the permanent disturbances caused by harmonics, such as buzzing in the power transformer and disruption of medium voltage conductors. These disturbances will be presented in a study of case involving the Substations (SE’s) Itacaiúna and Itupiranga. To prove how they can be harmful in these SE’s, campaigns of measurement were performed to obtain practical results and then, to perform studies involving simulations of short-circuit, load flow and spreading of harmonics in order to obtain an analytical diagnostic about the situations found and thus to issue recommendations to solve the problems identified. This study will provide a valuable support to the Concessionaire of Energy and it may be taken as a reference to the study of Power Quality in other substations, in addition to experimental basis for future charges from ANEEL, regarding the implementation of procedures in Electric Power Distribution National Electric System (PRODIST).
Acesso aberto (Open Access)
Planejamento de rede LTE utilizando aproximação híbrida de modelo empírico outdoor: medição e técnica de algoritmo genético
(Universidade Federal do Pará, 2015-03-20) PINHEIRO, Márcio Rodrigues; CAVALCANTE, Gervásio Protásio dos Santos; http://lattes.cnpq.br/2265948982068382
Currently, it is visible the growing number of mobile communications networks in the telecommunications scenario. In order to supply the demands of the most demanding users of mobile services with data transmission rates increasing constantly are developed by companies linked to the telecommunications industry, new technologies to keep up with these demands. As 2G and 3G networks can no longer bear the demands of current users because they can not provide quality services to customers due to limitations of data transfer rate. It was then developed, the LTE system (Long Term Evolution), which has become one of the most promising solutions to meet the growing demand of the telecommunications sector. In the LTE system, also called 4G is implemented efficiently on the network, various simulation tools to cover prediction has been developed. Great efforts have been invested in the development of these tools, in order that the predicted values are the closest possible to reality, making it indispensable in planning the LTE network. In this context, this paper is intended to study and optimization of outdoor propagation loss models available in the literature, operating in the 2.6GHz frequency range, in order to provide a propagation loss prediction more accurate the study environment. Therefore, signal measurements campaigns were held in Bethlehem in order to compare how satisfactory are the adjustments of the models of propagation loss with the signal loss measured in realized routes. It was observed that in certain measurements, models of propagation loss, did not show similar curves to that measured on the routes taken, showing high prediction error. Thus, optimization technique was used for all prediction models based on a Genetic Algorithm (GA). Through this technique, it was possible to achieve a significant improvement of the models studied compared the losses encountered on the routes taken, thus contributing to more efficient planning for networks operating in the LTE 2.6GHz range.