Thesis
Ratatoskr: wide-area actuator RPC over gridstat with timeliness, redundancy, and safety
Washington State University
Master of Science (MS), Washington State University
12/2007
DOI:
https://doi.org/10.7273/000005743
Abstract
The development of the communication infrastructure for the north-American electrical power
grid has failed to fully incorporate important developments in the field of computer science,
affecting the stability and efficiency of the power grid as a whole. The current power-grid
communication standard, SCADA, utilizes protocols specialized for centralized communication,
hampering communication between field sites key for envisioned improvements of power grid
safety and efficiency. Further, a number of different proprietary communication protocols are in
use, making communication between power utility companies very difficult.
GridStat is a communication infrastructure designed for a power grid environment that solves
many of the problems with the current situation. GridStat uses a specialization of the
publish-subscribe middleware paradigm, status dissemination, that takes advantage of the
semantics of status data to provide flexible acquisition of power-grid data with multiple
dimensions of QoS semantics. The middleware approach enables communication between
utilities independent of proprietary network protocols, and allows enhanced network features such as forwarding data through multiple redundant paths. While GridStat provides excellent support for data acquisition, the publish-subscribe architecture supports only one-way communication and provides syntax and semantics unsuitable for control communications.
This thesis presents Ratatoskr, a novel scheme for control of actuators using GridStat communication. It constructs a two-way communication channel on top of GridStat
publish/subscribe paths, and utilizes the QoS semantics and middleware properties GridStat
provides. For control communication Ratatoskr uses remote procedure call (RPC), providing
programmer friendliness and familiarity. The QoS semantics of GridStat are drawn upon to
provide the timeliness required for power-grid operation. Reliability concerns are addressed by
providing three redundancy schemes, ACK/resend, transmitting multiple copies of a single
packet, and spatial redundancy through GridStat’s redundant routing paths feature. Additionally,
pre- and post-condition expressions over GridStat status variables are built into call semantics.
The architecture and design of Ratatoskr is presented, along with results from an evaluation of a
prototype implementation.
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Details
- Title
- Ratatoskr
- Creators
- Erlend Smørgrav Viddal
- Contributors
- DAVID EDWARD BAKKEN (Chair) - Washington State University, School of Electrical Engineering and Computer ScienceCarl H Hauser (Committee Member) - Washington State University, School of Electrical Engineering and Computer ScienceMin Sik Kim (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of Electrical Engineering and Computer Science
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 85
- Identifiers
- 99901054757601842
- Language
- English
- Resource Type
- Thesis