Contribuições ao estudo dos aterramentos de sistemas monofilares com retorno pelo terra

• Autor(a) principal: Bertollo, Humberto Calil
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3526
• topic: Eletrificação rural; Energização; Aterramentos; Rural electrification; Energy; Grounding; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENERGIZACAO RURAL

This work presents a discussion on the possibility to reduce costs in rural electrification systems using a Single Wire Earth Return (SWER) system. It is presented a grounding project for a SWER system in low frequency applications, through the use of the image method, a simplification of the constant potential method and a state variable model in the Laplace domain for a grounding electrode for high frequency applications with changes in soil resistivity and in the length of the electrode, such models makes possible the analysis of the response of the grounding system to lightning discharges. For low frequency applications, the responses of three different grounding configurations were simulated: electrodes in triangular placement, electrodes placed in the corners of a square and nine electrodes placed in the corners of a grid with four squares. With the mentioned simulation it was possible to calculate the ground resistance and the surface voltage of each configuration. Obtained results were compared with values published by ELETROBRAS Centrais Elétricas Brasileiras S.A. for the minimum grounding resistance that keeps the surface voltage in safe levels for human beings and animals. Results showed that it is possible to use simpler and cheaper grounding configurations due to the fact that the surface voltages were kept in safe levels.