الفهرس 
PROTECTION FOR FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS: BASIC CONCEPTS AND LITERATUREOnly 14 pages are availabe for public view
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Abstract
FACTS is a new technology using power electronics for controlling the
parameters and structures of power systems for improving the power
transfer capability of the system.
Thyristor-Controlled Series Capacitor (TCSC) is a senes FACTS
device which allows rapid and continuous changes of the transmission
line impedance. However, this in turn introduces problems in
conventional distance protection.
The Static Synchronous Compensator (ST ATCOM) is introduced as a
powerful FACTS tool for reactive power compensation. The measured
impedance by distance relay at the relaying point in the presence of a
STATCOM on the transmission line depends on the controlling
parameters of STATCOM and on its installation location. The
conventional distance relay characteristics are greatly SUbjected to maloperation
in the form of over-reaching or under-reaching the fault point.
This thesis proposes an approach based on Artificial Neural Networks
(ANN) using the Total Least Square-Estimation of Signal Parameters via
Rotational lnvariance Technique (TLS-ESPRlT) for fault type
classification and faulted phase selection to be used in the protection of
series compensated (TCSC) transmission lines and also for the protection
of a transmission line employing STATCOM. The required features for
the proposed algorithm are extracted from transient currents and voltages
waveforms measured at the substation using TLS-ESPRlT. Since these
transient waveforms are considered as a summation of damped sinusoids,
TLS-ESPRlT is used to estimate different signal parameters mainly
damping factors and frequencies of different modes contained in the
signal. Those features can then be employed for fault type classification
and faulted phase selection.Two different learning algorithms are used for training the neural
network: Back propagation (BP) and Particle Swarm Optimization
techniques (PSO).
System simulation and results which are presented and analyzed in this
thesis indicate the feasibility of using neural networks with TLS-ESPRIT
in the protection of series compensated (TCSC) transmission lines and for
the transmission lines which using STATCOM.