Banca de DEFESA: FELIPE MENDES DE VASCONCELLOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : FELIPE MENDES DE VASCONCELLOS
DATA : 16/12/2020
HORA: 14:00
LOCAL: Videoconferência
TÍTULO:

Development of a Time-Frequency Hybrid Model for the Evaluation of the Lightning Performance of Transmission Lines Using EMTP-Type Platforms

PALAVRAS-CHAVES:

Lightning, Lightning Performance of Transmission Lines, Transmission Lines, Electromagnectic Transients in Power Systems, Grounding Systems, Surge Arresters, Frequency-Dependent Effects, Non-Linear Time-Dependent Elements.

PÁGINAS: 104
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Sistemas Elétricos de Potência
ESPECIALIDADE: Transmissão da Energia Elétrica, Distribuição da Energia Elétrica
RESUMO:

This thesis is dedicated to the study of the lightning performance of transmission lines. It proposes to include both frequency-dependent and non-linear time-dependent characteristics of the elements typically involved in this type of study, to establish consistent protection strategies and reduce the outage rates. A new model for the grounding system is proposed, based on transmission line theory, but not disregarding the electromagnetic coupling between the counterpoise cables arranged in parallel, as most works do. The model is validated comparing the results with those of the Hybrid Electromagnetic Model (HEM), based directly on Maxwell's Equations, widely used and recognized for its accuracy. The results obtained accuracy in the order of 100% to 96.1%, in concern to HEM, for typical configurations of transmission line grounding. From the systematic realization of hybrid time-frequency simulations using the proposed model, it is also characterized, in a general way, the influence of the dependence of the frequency of the soil electrical parameters in the performance of transmission lines against atmospheric discharges. It is concluded that disregarding this effect would lead to rough estimates of the actual performance of the line, which, when taken as true, would cause consequent errors in the protections applied to these electrical systems. Finally, it is proposed to evaluate the efficiency of the technique of partial protection of transmission lines by lightning devices through an innovative approach, by calculating the number of disconnections per line length per year with consideration or not of the variation of the electrical parameters of the ground with the frequency. Based on the results found, the efficiency of the technique of partial protection of transmission lines in maintaining the performance of these lines within the minimum requirements established by the regulatory agencies is proven, and again the importance of considering the frequency-dependent effect of the soil parameters in evaluating the lightning performance of transmission lines, with the risk of incurring technically inefficient and economically costly solutions.

MEMBROS DA BANCA:
Presidente - 1484412 - FERNANDO AUGUSTO MOREIRA
Interno - 1666309 - FABIANO FRAGOSO COSTA
Interno - 288126 - KLEBER FREIRE DA SILVA
Externo à Instituição - ANTÔNIO CARLOS SIQUEIRA DE LIMA - UFRJ
Externo à Instituição - MARCO AURELIO DE OLIVEIRA SCHROEDER - UFSJ
Externo à Instituição - RAFAEL SILVA ALÍPIO - CEFETE-MG