Banca de QUALIFICAÇÃO: JULIANA OLIVEIRA DE MEDEIROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JULIANA OLIVEIRA DE MEDEIROS
DATE: 15/12/2021
TIME: 15:00
LOCAL: Sala virtual Google Meet
TITLE:

A new algorithm for solving the fault equation in transmission lines with unknown electrical parameters

KEY WORDS:

Fault location, synchronization of oscillographic records, non-linear complex equations

PAGES: 20
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Sistemas Elétricos de Potência
SPECIALTY: Medição, Controle, Correção e Proteção de Sistemas Elétricos de Potência
SUMMARY:

The Brazilian electrical system composed by numerous transmission lines (LTs). These lines have large extensions, and are at all times exposed to natural weather and extreme conditions imposed by nature, being, therefore, the elements of the system most vulnerable to failures. In this sense, it is extremely important that the electrical system is monitored, controlled and easy and quick to maintain. Many works in the literature have developped tools with the objective of precisely determining the location of faults in transmission lines. However, before the fault location step, there must be a data processing step, which in [1] is composed of methods capable of synchronizing the records, estimating the electrical parameters of the line from voltage phasors and pre-fault current, identify the instant when the fault occurs, and estimate the post-fault voltage and current phasors.
After synchronizing the records and estimating the electrical parameters of the line, it is necessary to obtain the post-fault voltage and current phasors that will feed the localization methodologies. Thus, it is necessary to use a method to identify the sample in which the fault occurs, from which the phasors will be extracted. The method used in this work to identify the fault onset instant or sample was based on the comparison of two consecutive cycles of the sampled signal.

In the reference article [1], two proposals for the solution of the fault equation were presented, whose coefficients are dependent on the knowledge of the electrical parameters of the transmission line. In the reference work [2], the demonstration of a new fault equation was presented, which does not depend on the knowledge of these parameters. This equation resulted from an improvement of the methodology proposed in reference [3]. The result is a quadratic equation, with complex coefficients. This equation produces four solutions, from which you need to choose the most feasible one. This requires an additional algorithm to choose from.

The objective of the work is to propose a new algorithm for solving the fault equation proposed in [2], obtained after the synchronization of the phasors proposed in the same reference. Several simulations will be performed, assuming different values for errors in voltage and current phasors, to compare the performance of the different methodologies studied.

[1] OLIVEIRA NETO, M. H.; DA CRUZ, M. C. S.; MEDEIROS, J. O.; MEDEIROS JUNIOR, M. F. Duas Propostas para Solução de Equações de Localização de Faltas no Contexto de Dados Não Sincronizados Originados de Dois Terminais de Linhas de Transmissão. CBQEE, 2021.
[2] MONTEIRO, R. D. S.; DA CRUZ, M. C. S.; LOPES, F. V.; MEDEIROS, J. O.; MEDEIROS JUNIOR, M. F. Parameters-Free Non-Iterative Two-Terminal Measurements Synchronization Algorithm. IJEPES, 2021.
[3] APOSTOLOPOULOS, C. A.; KORRES, G. N. A Novel Algorithm for Locating Faults on Transposed/Untransposed Transmission Lines without Utilizing Line Parameters. IEEE Transactions on Power Delivery, vol. 25, n. 4, p. 2328-2338, Out. 2010.

BANKING MEMBERS:
Presidente - 346287 - MANOEL FIRMINO DE MEDEIROS JUNIOR
Externo ao Programa - 346989 - JOSE TAVARES DE OLIVEIRA
Externa à Instituição - MELINDA CESIANARA SILVA DA CRUZ - UFERSA