This dissertation studied new transmission line fault diagnosis approaches using
new technologies and proposed a scheme to apply those techniques in preventing and
mitigating cascading blackouts. The new fault diagnosis approaches are based on two
time-domain techniques: neural network based, and synchronized sampling based.
For a neural network based fault diagnosis approach, a specially designed fuzzy
Adaptive Resonance Theory (ART) neural network algorithm was used. Several ap-
plication issues were solved by coordinating multiple neural networks and improving
the feature extraction method. A new boundary protection scheme was designed by
using a wavelet transform and fuzzy ART neural network. By extracting the fault gen-
erated high frequency signal, the new scheme can solve the difficulty of the traditional
method to differentiate the internal faults from the external using one end transmis-
sion line data only. The fault diagnosis based on synchronized sampling utilizes the
Global Positioning System of satellites to synchronize data samples from the two ends
of the transmission line. The effort has been made to extend the fault location scheme
to a complete fault detection, classification and location scheme. Without an extra
data requirement, the new approach enhances the functions of fault diagnosis and
improves the performance.
Two fault diagnosis techniques using neural network and synchronized sampling
are combined as an integrated real time fault analysis tool to be used as a reference of traditional protective relay. They work with an event analysis tool based on event tree
analysis (ETA) in a proposed local relay monitoring tool. An interactive monitoring
and control scheme for preventing and mitigating cascading blackouts is proposed.
The local relay monitoring tool was coordinated with the system-wide monitoring
and control tool to enable a better understanding of the system disturbances. Case
studies were presented to demonstrate the proposed scheme.
An improved simulation software using MATLAB and EMTP/ATP was devel-
oped to study the proposed fault diagnosis techniques. Comprehensive performance
studies were implemented and the test results validated the enhanced performance
of the proposed approaches over the traditional fault diagnosis performed by the
transmission line distance relay
