The electric power grid is operated with exceptionally high levels of reliability, yet recent large-scale outages have highlighted areas for improvement in operation, control, and planning of power systems. Synchrophasor technology may be able to address these concerns, and Phasor Measurement Units (PMUs) are actively being deployed across the Western Interconnection and North America. Initiatives such as the Western Interconnection Synchrophasor Program (WISP) are making significant investments PMUs with the expectation that wide-area, synchronized, high-resolution measurements will improve operator situational awareness, enable advanced control strategies, and aid in planning the grid.
This research is multifaceted in that it focuses on improved operator awareness and alarming as well as innovative remedial controls utilizing synchrophasors. It integrates existing tools, controls, and infrastructure with new technology to propose applications and schemes that can be implemented for any utility. This work presents solutions to problems relevant to the industry today, emphasizing utility design and implementation. The Bonneville Power Administration (BPA) and Western Electricity Coordinating Council (WECC) transmission systems are used as the testing environment, and the work performed here is being explored for implementation at BPA. However, this work is general in nature such that it can be implemented in myriad networks and control centers.
A Phase Angle Alarming methodology is proposed for improving operator situational awareness. The methodology is used for setting phase angle limits for a two-tiered angle alarming application. PMUs are clustered using an adapted disturbance-based probabilistic rms-coherency analysis. While the lower tier angle limits are determined using static security assessment between the PMU clusters, the higher tier limits are based on pre-contingency operating conditions that signify poorly damped post-contingency oscillation ringdown. Data mining tools, specifically decision trees, are employed to determine critical indicators and their respective thresholds. An application is presented as a prototype; however, the methodology may be implemented in online tools as well as offline studies.
System response to disturbances is not only dependent on pre-contingency conditions but also highly dependent on post-contingency controls. Pre-defined controls such as Special Protection Schemes (SPSs) or Remedial Action Schemes (RAS) have a substantial impact on the stability of the system. However, existing RAS controls are generally event-driven, meaning they respond to predetermined events on the system. This research expands an existing event-driven voltage stability RAS to a response-based scheme using synchrophasor measurements. A rate-of-change algorithm is used to detect substantial events that may put the WECC system at risk of instability. Pickup of this algorithm triggers a RAS that provides high-speed wide-area reactive support in the BPA area. The controls have proved effective for varying system conditions and topologies, and maintain stability for low probability, high consequence contingencies generally dismissed in today's deterministic planning studies.
With investments being made in synchrophasor technology, the path of innovation has been laid; it's a matter of where it goes. The goal of this research is to present simple, yet highly effective solutions to problems. Doing so, the momentum behind synchrophasors can continue to build upon itself as it matures industry-wide. / Ph. D.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/50576 |
| Date | 25 April 2013 |
| Creators | Quint, Ryan David |
| Contributors | Electrical and Computer Engineering, Centeno, Virgilio A., Thorp, James S., Van Aken, Eileen M., Shukla, Sandeep K., De La Ree, Jaime |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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