Effects of STATCOM, SSSC and UPFC on Voltage Stability
R. Natesan
Department of Electrical and Computer Engineering
Tennessee Technological University
Cookeville, Tennessee, USA
email: rnatesan2 1 @,tntech.edu
G. Radman, Member, IEEE
Department of Electrical and Computer Engineering
Tennessee Technological University
Cookeville, Tennessee, USA
email: gradman@tntech.edu
Keywords: STATCOM, SSSC, UPFC, Maximum Loadability, Bifurcations, Voltage Collapse.
Abstract-The
purpose of this paper is to study the
effects of three FACTS controllers: STATCOM, SSSC
and UPFC on voltage stability in power systems.
Continuation power flow, with accurate model of these
controllers, is used for this study. Applying saddle
node bifurcation theory with the use of Power System
Analysis Toolbox (PSAT), the optimal location of these
controllers are determined. Using a 6-bus test system
the effects of these controllers on voltage stability are
examined. It
is
found that these controllers
significantly increase the loadability margin of power
systems.
I. INTRODUCTION
Voltage collapse phenomena in power systems
have become one of the important concerns in the power
industry over the last two decades, as this has been the
major reason for several major blackouts that have
occurred throughout the world including the recent
Northeast Power outage in North America in August
2003. Point of collapse method and continuation method
are used for voltage collapse studies [l]. Of these two
techniques continuation power flow method is used for
voltage analysis. These
techniques
involve
the
identification of the system equilibrium points or voltage
collapse points where the related power flow Jacobian
becomes singular [2, 31.
The voltage collapse occurs when a system is
loaded beyond its maximum loadability point. Voltage
collapse studies are carried out with the aim to maximize
the loading capability of a particular transmission line.
Traditionally shunt and series compensation is used to
maximize the tr