CALAZANS, Adolpho Eugenio de Andrade Lima; http://lattes.cnpq.br/7133946268765182
Resumo:
Nowadays the Static VAr Compensators is a equipment
essentially important for the electric power system. The rapid
development technologic has offered the Static VAr Compensators
(SVC) as solution to a number of problems encountered in electric
power system. However, research in degradation of semiconductors
applied in SVC is still developing.
The objective of this dissertation is to introduce a
methodology for diagnosing semiconductors degradation, applied in
SVC type Thyristor Switched Capacitor (TSC) and Thyristor
Controlled Reactor (TCR), resulting in the improvement of
operational performance of SCV. It also presents the results of tests
carried out in semiconductors during different stages of degradation,
and how the junction temperature affects the semiconductor blocking
capability.
In Chapter 1, general comments are made on the importance
of the SVC in electric power systems and the research development
on semiconductors degradation, especially in the context of actual
Brazilian Electric Model.
In Chapter 2, there are some comments about the benefices of
SVC´s application. Following this, in Chapter 3, the main types of
SVC are presented, and the basic configuration of the SVC
researched.
Avaliação da Degradação de Semicondutores de Potência Com o Uso Contínuo em Compensadores Estáticos
Universidade ederal de Itajubá x
Next, in Chapter 4, a performance analysis of SVC in service
in national grid of Brazil is done, emphasizing failure rates of
semiconductors e availability rates of SVC.
In Chapter 5, a brief review of semiconductors theory is
provided, considering the electrical characteristics of thyristors and
diodes. It Chapter 6, the failures of semiconductors are analyzed and
classified according to the characteristics of damage.
Following this, in Chapter 7, the concept of various levels of
degradation (normal, defect and failure) is introduced. It is presented
which parameters of semiconductors shall be analyzed to determinate
the level of degradation.
In Chapter 8, the results of tests carried out in
semiconductors during different stages of degradation are discussed,
highlighting the analysis of voltage-current characteristics, and the
behavior of the leaking current when the maximum ratings of
repetitive peak off-state voltage and repetitive peak reverse voltage
are applied. The manner in which junction temperature affects the
semiconductor blocking capability is also presented.
Finally, in Chapter 9, conclusions are drawn. Some
recommendations are given, including proposals for developing of
new research projects.