ÇUKUROVA UNIVERSITY INSTITUTE OF NATURAL AND APPLIED ...

ABSTRACT
MSc THESIS
MODELING AND ANALYSIS OF MULTILEVEL INVERTER BASED
DYNAMIC VOLTAGE RESTORER WITH DC-DC CONVERTER
Mustafa İNCİ
ÇUKUROVA UNIVERSITY
INSTITUTE OF NATURAL AND APPLIED SCIENCES
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
Supervisor : Assoc. Prof. Dr. K. Çağatay BAYINDIR
Year : 2013, Pages 126
Jury : Assoc. Prof. Dr. K. Çağatay BAYINDIR
: Prof. Dr. Mehmet TÜMAY
: Assoc. Dr. Ramazan ÇOBAN
Voltage, current, frequency deviations and waveform distortions that causes
equipment failure, economical loss and several negative effects are known as power
quality problems. Among the power quality problems, voltage sags and swells are
the most significant disturbances. The dynamic voltage restorer (DVR) is the most
effective and economical custom power device applied to protect sensitive loads
from voltage sags and swells.
In this thesis, dynamic voltage restorer with dc-dc converter is modeled in
PSCAD/EMTDC. DC-DC converter is used to maintain and control the dc voltage of
the inverter during voltage sag. The developed topology permits to use in medium
power systems. Multilevel inverter is used to allow high power-handling than the
two-level inverter. EPLL, SRF and SOGI-PLL is used to detect and extract the
voltage sag and swell. SOGI-PLL is a new method to extract voltage magnitude and
phase angle simultaneously. The comparison results of EPLL, SRF and SOGI-PLL
are presented in thesis. The performance of DVR is evaluated through simulations
for compensation of balanced and unbalanced voltage sags.
The main purpose of this thesis is analyzing and modeling of DVR, which
protects a 1-MVA nonlinear load. The performance results of the proposed topology
are presented with different cases by PSCAD/EMTDC program.
Keywords: Dynamic Voltage Restorer, Voltage Sag and swell, Power Quality, DC-
DC Converter, Multilevel Inverter
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