Resumo:
This work describes the phenomenon of the power system voltage stability, which has become an
interesting point over the last decades. Economical and environmental constraints are causing
stressful operating conditions on many power systems and incidents around the world due to
voltage instability.
Voltage stability is a dynamic problem. However, the phenomenon may be studied by
static tools, using a power flow model, enabling one to calculate the system load margin and
identify the critical area.
Dynamic system model is necessary if the time domain simulation is required. In this
simulation, many power systems components, controls, protection and disturbances may be
considered, enabling one to capture the trend of the system.
When voltage stability problems were first described in the literature, many methodologies
were proposed, but engineers had no effective computational programs that could be used.
Because there is a wide range of programs available nowadays, the aim of this work is to
carry out a comparative analysis of some methodologies with the help of the results obtained with
the Brazilian power system.
In this sense, this work aims to contribute to the understanding of the problem, and since no
methodology is favored, the similarities and differences among the methods are discussed. For this
purpose, the state of the art is provided and the potentialities of each method are highlighted.
It is expected that the engineers involved in this area of work and research may obtain
some important pieces of information about the interpretation of the results from each approach
adressed in this work.
