Dissertation
Voltage Stability Assessment and Control Based on Synchrophasor Measurements in Ambient Condition
Washington State University
Doctor of Philosophy (PhD), Washington State University
12/2019
DOI:
https://doi.org/10.7273/000005576
Abstract
Voltage stability assessment and control are among the top priority tasks for electric utilities and power system operators. Failure in performing these correctly, has resulted in some of the major blackouts over the past few decades. Continuous loading increase on system infrastructure, higher reliability and security requirements, as well as progressive renewable resource integration, incapable of guaranteeing sustained reactive support, have all made this function more complex, and yet more crucial.Traditionally, developed algorithms for calculating voltage stability margin and recommending the necessary control action, rely on complete and accurate system models, as well as extensive offline studies. Investigating previous incidents has proved this to be a challenging goal to achieve. At the same time, integration of high-sampling measurement devices such as synchrophasors, powerful processors, and fast communication have resulted in increased situational awareness and monitoring quality of the system behavior. As a result, there is high interest today, to develop measurement-based real-time tools for determining system status from stability point of view and deduce the optimal control actions in critical conditions.In this dissertation, accurate modeling of the power system ambient data, corresponding to its operation at quasi steady-state condition is discussed, and the difference between system's steady-state response and power flow solutions is investigated. Based on this clarification, a new distributed model-free algorithm is proposed for voltage stability assessment and control of a power system, based on steady-state Q-V sensitivity of system buses. This is realized through subspace system identification from input-output response based on ambient measurements. Once the sensitivities are known, system proximity to voltage instability can be determined using the minimum sensitivity, rank system buses according to their stability margin and the need for corrective control actions, and determine the optimal set of actions needed to bring system operation point back to a secure state. To pursue the latter, two optimization approaches with different objectives based on various operating policies are introduced towards finding the best local control action within a substation. Finally, an index is introduced to determine vulnerability of the system to voltage instability caused by limitation on a generator's reactive power.
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Details
- Title
- Voltage Stability Assessment and Control Based on Synchrophasor Measurements in Ambient Condition
- Creators
- Sayed Mohammad Amelian
- Contributors
- Mani Vaithianathan Venkatasubramanian (Chair)Anjan Bose (Committee Member) - Washington State University, Electrical Engineering and Computer Science, School ofKrishnamoorthy Sivakumar (Committee Member) - Washington State University, Voiland College of Engineering and Architecture
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 86
- Identifiers
- 99901054232601842
- Language
- English
- Resource Type
- Dissertation