الفهرس 
Flexible AC Transmission systems (FACTS)Only 14 pages are availabe for public view
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Abstract
The rapid development of power electronics technology provides
opportunitie to develop new power equipment to improve the performance
of electric power systems. During the last decade, a number of control
devices called Flex ible AC Transmission Systems (FACTS) have been
proposed and implemented. FACTS devices can be used to fulfil many
objectives, such as power flow control, loop-flow control or combination of
both. The converters used in the most dominant FACTS devices, such as the
static synchronous compensator (STATCOM), the static synchronous series
compensator (SSSC) and, by the combination of both, the Unified power
Flow controller (UPFC), are of the voltage-source types.
The Static Phase shifter (SPS) and the unified power flow controller (UPFC)
are the most commonly used devices in power systems for controlling power
flow, with the ability to simultaneously control the voltage at transmission
line ends, line impedance, and phase angle. The development of fast high
power semiconductor devices enables the UPFC to be the most powerful
FACTS device in power flow control. FACTS devices ensure their
capability in improving power system performance and the development of
AI based-controllers facilitates the application of these devices under system
varying conditions and to get the best system performance under di fferent
operating conditions.
The work done in this thesis ensured the effectiveness of using the Static
Phase Shifter (SPS) and the Unified Power Flow Controller (UPFC) in
steady state power flow control with special emphasis on improving the voltage profile. enhancing power system security and reducing power system
tran smission losses. The principles and the control characteristics of the SPS
and UPFC have been investigated. In addition, power injection models of
these devices have been developed and successfully incorporated into a
standard load now program to control the power flow and achieve other
operation objectives of the study systems. The use of FACTS devices in
one circuit and in both circuits of a double circuit line has been studied. The
developed technique has been applied to two IEEE test systems (a 6-bus
system and a 25- bus system). The simulation results obtained ensured that
the research technique is acceptable and successfully applicable to control
the steady state power flow in the systems under normal and abnormal
conditions.
A novel ANN-based control concept for the UPFC has been developed.
UPFCs with A]\TN- based controllers has been successfully applied to fix the
power flow in the associated lines at pre-specified values in a wide range of
system load variation.