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Measurement enhancement for state estimation

After the deregulation of the power industry, power systems are required to be
operated efficiently and economically in today’s strongly competitive environment. In
order to achieve these objectives, it is crucial for power system control centers to
accurately monitor the system operating state. State estimation is an essential tool in an
energy management system (EMS). It is responsible for providing an accurate and
correct estimate for the system operating state based on the available measurements in
the power system. A robust state estimation should have the capability of keeping the
system observable during different contingencies, as well as detecting and identifying
the gross errors in measurement set and network topology. However, this capability
relies directly on the system network configuration and measurement locations. In other
words, a reliable and redundant measurement system is the primary condition for a
robust state estimation.
This dissertation is focused on the possible benefits to state estimation of using
synchronized phasor measurements to improve the measurement system. The benefits
are investigated with respect to the measurement redundancy, bad data and topology error processing functions in state estimation. This dissertation studies how to utilize the
phasor measurements in the traditional state estimation. The optimal placement of
measurement to realize the maximum benefit is also considered and practical algorithms
are designed. It is shown that strategic placement of a few phasor measurement units
(PMU) in the system can significantly increase measurement redundancy, which in turn
can improve the capability of state estimation to detect and identify bad data, even
during loss of measurements. Meanwhile, strategic placement of traditional and phasor
measurements can also improve the state estimation’s topology error detection and
identification capability, as well as its robustness against branch outages. The proposed
procedures and algorithms are illustrated and demonstrated with different sizes of test
systems. And numerical simulations verify the gained benefits of state estimation in bad
data processing and topology error processing.

Identiferoai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2717
Date15 May 2009
CreatorsChen, Jian
ContributorsAbur, Ali
Source SetsTexas A and M University
Languageen_US
Detected LanguageEnglish
TypeBook, Thesis, Electronic Dissertation, text
Formatelectronic, application/pdf, born digital

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