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Center for Nonlinear Studies |
In this talk we concentrate on data integrity attacks to power grid data. Real power injections at loads and generators, and real power flows on selected lines in a transmission network are monitored, transmitted over a SCADA network to the system operator, and used in state estimation algorithms to make dispatch, re-balance and other energy management system [EMS] decisions. Coordinated cyberattacks of power meter readings can be arranged to be undetectable by any bad data detection algorithm. These unobservable attacks present a serious threat to grid operations. Of particular interest are sparse attacks that involve the compromise of a modest number of meter readings. The contribution of our work are the following. In the special circumstance where all lines are metered, we derive canonical forms for 3, 4, and 5-sparse unobservable attacks in terms of the graph of the power network. And, given a power network, we offer an algorithm to find them. We next consider the problem of using known-secure PMUs to thwart an arbitrary collection of cyberattacks. We offer a characterization of buses at which these PMUs must be placed to mitigate the collection of attacks. Finding the minimum number of necessary PMUs is NP-hard. We show that it is sufficient to place p+1 PMUs at carefully chosen buses to neutralize a collection of p cyberattacks.
Host: Kipton Barros, T-4 and CNLS