Untitled - Programa de Engenharia Elétrica - UFRJ

Abstract of Thesis presented to COPPE/UFRJ as a partial fulfillment of the
requirements for the degree of Doctor of Science (D.Sc.)
STATE ESTIMATION UTILIZING NON-QUADRATIC AND CONTINUOS
OBJECTIVE FUNCTIONS
Luiz Antonio Cordeiro Pereira
November/2007
Advisor: Djalma Mosqueira Falcão
Department: Electrical Engineering
This work presents an alternative approach to the state estimation function,
which aims at the improvement of the algorithm related with the detection and
identification of bad data.
The methodology developed includes the evaluation and utilization of
non-quadratic objective functions that should be continuous and differentiable. These
functions should have a quadratic profile for small values of the estimation residual,
and a linear or constant profile for great values of the estimation residual. The
utilization of these functions aims to mitigate the effect of bad data spread, which
occurs in the standard minimum least square method. The methodology also aims at
the identification of bad data during the calculation of system state. The main
contribution of this work is the modeling of the state estimation problem through
non-quadratic, continuous and differentiable objective functions.
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