This dissertation has focused on automated power system fault analysis. New
contributions to fault section estimation, protection system performance evaluation
and power system/protection system interactive simulation have been achieved. Intelligent techniques including expert systems, fuzzy logic and Petri-nets, as well as
data from remote terminal units (RTUs) of supervisory control and data acquisition
(SCADA) systems, and digital protective relays have been explored and utilized to
fufill the objectives.
The task of fault section estimation is difficult when multiple faults, failures
of protection devices, and false data are involved. A Fuzzy Reasoning Petri-nets
approach has been proposed to tackle the complexities. In this approach, the fuzzy
reasoning starting from protection system status data and ending with estimation of
faulted power system section is formulated by Petri-nets. The reasoning process is
implemented by matrix operations. Data from RTUs of SCADA systems and digital
protective relays are used as inputs. Experiential tests have shown that the proposed
approach is able to perform accurate fault section estimation under complex scenarios.
The evaluation of protection system performance involves issues of data acquisition, prediction of expected operations, identification of unexpected operations and
diagnosis of the reasons for unexpected operations. An automated protection system performance evaluation application has been developed to accomplish all the tasks. The application automatically retrieves relay files, processes relay file data,
and performs rule-based analysis. Forward chaining reasoning is used for prediction
of expected protection operation while backward chaining reasoning is used for diagnosis of unexpected protection operations. Lab tests have shown that the developed
application has successfully performed relay performance analysis.
The challenge of power system/protection system interactive simulation lies in
modeling of sophisticated protection systems and interfacing the protection system
model and power system network model seamlessly. An approach which utilizes the
"compiled foreign model" mechanism of ATP MODELS language is proposed to model
multifunctional digital protective relays in C++ language and seamlessly interface
them to the power system network model. The developed simulation environment
has been successfully used for the studies of fault section estimation and protection
system performance evaluation.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/5797 |
| Date | 17 September 2007 |
| Creators | Luo, Xu |
| Contributors | Kezunovic, Mladen |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 2090121 bytes, electronic, application/pdf, born digital |
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