2016-08-292016-03-29SILVA, Bárbara Pereira. Modelagens e solução de aterramentos sujeitos a surtos de corrente: respostas nos domínios da frequência e do tempo. 2016. 126 f. Dissertação (Mestrado em Engenharia Elétrica) - Universidade Federal de Goiás, Goiânia, 2016.http://repositorio.bc.ufg.br/tede/handle/tede/6018In the grounding systems analysis, the investigation of the effects caused by lightning discharge is a crucial task, since it is the main electromagnetic phenomena responsible for electricity outages which can be the cause of severe mechanical and thermal stresses on electric installations. This dissertation presents a study of transient behavior for various grounding configurations subject to impulsive currents originated from incident discharges. The model is named hybrid electromagnetic model, because it is based on electromagnetic equations and it is used concepts of electrical circuit analysis. The modeling is performed in frequency domain considering the effects of electromagnetic propagation on the metal electrode and into surrounding soil. In the numerical solution of model is used the method of moments for the discretization of the electrodes and calculus of the impedances. This methodology also considers the variation of electric soil parameters when frequency varies. The modeling comprised the effects of propagation and electromagnetic couplings between the grounding electrodes. Results were obtained for simple electrodes (wire horizontally buried in the soil or a vertical rod) and grounding grid in square format from the computational implementation of the mathematical model. This tool and the results obtained lend itself to the determination of the grounding systems response subjected to an injection of a typical current of lightning discharge. The validation of the tool which resulted from this work is made by comparing the obtained results with results of similar cases reported in the technical literature.application/pdfAcesso AbertoAnálise transitóriaAterramentoModelo eletromagnético híbridoMétodo dos momentosTransient analysisGroundingMoments methodHybrid electromagnetic modelENGENHARIA ELETRICA::CIRCUITOS ELETRICOS, MAGNETICOS E ELETRONICOSDissertação