Banca de QUALIFICAÇÃO: Laice Neves de Oliveira

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Laice Neves de Oliveira
DATE: 25/06/2024
TIME: 14:00
LOCAL: VIDEOCONFERÊNCIA
TITLE:

IMPACT OF PERTURBATION APPROACHES IN THE SOLUTION OF ILL-CONDITIONED LARGE-SCALE POWER FLOW PROBLEMS

KEY WORDS:

Power flow problem; Newton-Raphson method; ill-conditioned system; conditioning step; Heun-King-Werner; MATPOWER.

PAGES: 74
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUMMARY:

This PhD thesis proposal presents approaches to calculate the solution to the Power Flow
Problem (PFP) involving ill-conditioned and large systems. The strategy is based on applying
a conditioning step to the initial estimate used in iterative methods. This step consists of
modifying the initial estimate of the iterative method through a process that involves the Jacobian
matrix and the mismatch of the balance equations, both calculated for the initial estimate.
The Jacobian matrix is then used to form a linear system whose perturbed matrix results in a
better condition number. Another perturbation approach proposed in this work based on modal
analysis demonstrates that the primary cause of the ill-conditioning problem is associated
with the smallest magnitude eigenvalue of the Jacobian matrix’s first iteration. In addition,
it is proposed a procedure to circumvent this problem by shifting away from zero the smallest
magnitude eigenvalue of the Jacobian matrix. Finally, the last proposed approach is based on a
hybrid method to calculate the PFP solution that is composed of two steps. The first consists
of calculating a partial solution of the PFP based on an estimate flat start. Calculations are
performed using a homotopy technique. The states computed in this first step are used in the
second as estimates for an iterative method, which determines the precise and final solution of
the PFP. The proposed techniques were investigated considering the classical NR method, the
Heun-King-Werner (HKW) method and some variants. The performance of the proposed approaches
is evaluated for a variety of test systems, including a 70,000 bus system. The results
obtained demonstrated that the investigated methods were able to significantly improve the
convergence process of the iterative techniques used to solve large and ill-conditioned PFPs,
including the classical Newton-Raphson method.
Keywords:

COMMITTEE MEMBERS:
Externo à Instituição - ROBSON CELSO PIRES - UNIFEI - UNI
Interno - 1084535 - AMAURI GUTIERREZ MARTINS BRITTO
Interno - 3145900 - FERNANDO CARDOSO MELO
Presidente - 404862 - FRANCISCO DAMASCENO FREITAS
Externo à Instituição - RODRIGO ANDRADE RAMOS - USP