Navegando por Assunto "Atmospheric discharges"

Agora exibindo 1 - 5 de 5

Acesso aberto (Open Access)
Análise bidimensional dos efeitos das descargas atmosféricas em cabos OPGW utilizando o método ADI-FDTD
(Universidade Federal do Pará, 2013-07-15) GOMES, Kellen Diane de Carvalho; DMITRIEV, Victor Alexandrovich; http://lattes.cnpq.br/0684541646225359
In this work it is analyzed the behavior of the electrical current density in OPGW cables when they are subjected to lightning. For this analysis, two models of current were applied, since lightning has two main components that usually cause more damages in the cable: the impulsive component and the direct-current component. The numerical method used for computer simulations is the method ADI-FDTD (Finite Difference Time Domain of Alternating Directions Implicit), which is truncated by CPML technique (Convolutional Perfectly Matched Layers). Based on the behavior of current in the cable, it is done an evaluation to determine which lightning component can cause more damages to the OPGW cable.
Acesso aberto (Open Access)
Análise de tensões induzidas em linhas de distribuição de baixa tensão frente a uma descarga atmosférica
(Universidade Federal do Pará, 2009-09-15) CHAMIÉ FILHO, Ricardo Hachem Thomé; SOUZA SOBRINHO, Carlos Leônidas da Silva; http://lattes.cnpq.br/1450994881555781
Numerical full-wave solutions of induced voltages on low-voltage energy lines due to atmospheric discharges on cell phone radio base stations (RBS), installed at the proximities of such lines, are presented for the first time in this work. Structures, such as towers and buildings, which present high structural complexity, have been modeled in order to obtain realistic results. In particular, this paper shows the importance of considering the effects related to real electrical conductivity and permittivity of the soil (in technical literature, PECs have been used to represent the soil in similar problems). For this purpose, a software has been developed in which Maxwell’s equations are numerically solved by using a parallel implementation of the Finite-Difference Time-Domain Method (FDTD), producing full wave solutions for the problem. The thin wire formulation has been implemented for representing thin cylindrical electric conductors and transmission lines.
Acesso aberto (Open Access)
Estimação do local de incidência da descarga atmosférica utilizando o método TOA e tempos artificiais de detecção dos sensores
(Universidade Federal do Pará, 2016-03-22) MIRANDA, Bruno Nazareno Prazeres de; MACEDO, Valquiria Gusmão; http://lattes.cnpq.br/4288739747304808; ROCHA, Brigida Ramati Pereira da; http://lattes.cnpq.br/9943372249006341
Over the years, lightning were the central point of researches in various scientific communities around the world, no doubt for its aggressive and devastating nature, but mostly for damage caused in the electricity sector, so it is necessary to clarify what is and what it is for a Lightning Location System (LLS). This work proposes to demonstrate the operation of the algorithm utilized in LLS that is used to locate in geographical terms, lightning, using the arrival times of electromagnetic signals in the sensors. In order to prepare this paper it was used the data format generated by LPATS IV sensors belonging to Amazon Protection System (SIPAM). These data were generated in an artificial way for use in the algorithm tests. The lightning location will be based on a finite sequence rules that use the intersection of hyperbolas, resulting from the difference of arrival times at each sensor. The algorithm is able to identify the lightning location incidence using a system with three sensors. Each pair of sensors defines two hyperbole forming a total of six, because each hyperbole has a bright side and a negative side, so there will be two intersections of three hyperboles. For analysis of the results is considered the nearest crossing point to the sensor that identified the electromagnetic disturbance faster. Studies about atmospheric electricity, lightning types, electromagnetic radiation during storms, types of electromagnetic sensors and lightning detection networks have given the knowledge to develop the algorithm.
Acesso aberto (Open Access)
Estudo dos efeitos das descargas atmosféricas nos índices de desempenho da Subestação de Vila do Conde
(Universidade Federal do Pará, 2014-09-11) PEREIRA, Jorge Luiz Moreira; ROCHA, Brigida Ramati Pereira da; http://lattes.cnpq.br/9943372249006341
This work aims to present the effects of lightning performance indexes in VDC (substation of Vila do Conde), located in the northern region, in the State of Pará, in the period from 2005 to 2013, establishing the relationship between the weather information provided by the SIPAM and data provided by the center of operations for Eletronorte in order to perform and determine the harmful effects of atmospheric discharges, which are responsible for the intensification of interruptions in the supply of electricity.The analysis is restricted to the area of expertise of Eletronorte (substation of Vila do Conde) which has much of its power transmission Lines installed in northern Brazil. The results show that the incidence of lightning can cause direct and indirect surges in transmission lines and substations of high power. In this context justifies the study of efficient forms of prevention, being one of the purposes of this work, which aims to provide general information concerning the effects produced by the action of atmospheric discharges in substations of the power sector as the quality of energy, in particular in the VDC – Eletrobrás System-Eletronorte.
Acesso aberto (Open Access)
Estudos dos efeitos das descargas atmosféricas nos índices de desempenho da subestação de Vila do Conde e subestação de Marabá
(Universidade Federal do Pará, 2016-05-10) SANTOS, Luciano Silva dos; PROTAZIO, João dos Santos; http://lattes.cnpq.br/4210442535067685; ROCHA, Brigida Ramati Pereira da; http://lattes.cnpq.br/9943372249006341
This paper aims to present the effects of lightning in the performance indices in Vila do Conde substation (SE VDC) and Maraba (SE MB), which are situated in the north, in the state of Pará, integrating the North System - Eletronorte Transmission northeast, being connected to the Tucuruí Hydroelectric Power Plants (HPP Tucuruí). They were studied, establishing relations between the weather information provided by the SIPAM and data provided by central Eletronorte's operations in the period 2005-2013 in order to determine the harmful effects of lightning, which are responsible for the intensification of supply interruptions electricity. The analysis restricted to the area of operation of Eletronorte SE and SE VDC MB. The study developed evidence disconnections by lightning on transmission line VDC / CASTANHAL 230 KV and 500 KV breaker VCDJ7-08 and transmission line MB / Empress of 500 KV. The results demonstrate that a lightning strike may cause direct and indirect surges in transmission lines and high power substations. In this context it justifies the study of efficient forms of prevention, one of the purposes of this work.