On Wednesday, October 30, 2013, at 4 pm, Prof. Christopher L. DeMarco of the Department of Electrical and Computer Engineering at the University of Wisconsin - Madison will present a lecture titled "Cascading Failure Dynamics in Power Grids, with Analogies in Computational Chemistry" as part of the Grainger Lecture Series. This lecture will take place in B02 Coordinated Science Laboratory.
The last decade has seen extensive effort devoted to analysis of power grid cascading failure, in which initial outage of a small number of network elements subsequently overloads other components, forcing their removal from service, in turn overloading additional components, potentially expanding to a large largescale blackout. These methods have been largely restricted to steady state models, while experience in outage events indicates that transient power swings often dominate the final stages of cascading failure, suggesting the need to represent dynamics.
Work here develops a dynamic model for cascading grid failure, augmenting "swing dynamics" with specially structured, smoothed representations of protective relays that disconnect transmission lines, generators, and loads. This construction offers a nearly Hamiltonian structure, with the gradient of a scalar "potential-like" function playing a key role. Any partially degraded network configuration yields an equilibrium point, locally stable if that configuration is operable. Cascading failure is then a sequence of transitions between these degraded network equilibria, with vulnerability to transition characterized by the potential barrier to be overcome along a transition path. Exploiting analogous problems in computational chemistry, this talk will describe adaptation of Nudged Elastic Band and String methods to transition path calculation in the power context.
Christopher DeMarco holds the Grainger Professorship in Power Engineering at the University of Wisconsin-Madison, where he been a member of the faculty of Electrical and Computer Engineering (ECE) since 1985. He has served as ECE Department chair (2002-2005), and is UW-Madison site director for the National Science Foundation IUCRC Power Systems Engineering Research Center (2004-present). He was recipient of the UW-Madison Chancellor's Distinguished Teaching Award in 2000. Dr. DeMarco received his PhD degree at the University of California, Berkeley in 1985, and his B.S. degree from the Massachusetts Institute of Technology in 1980, both in electrical engineering and computer sciences. His research and teaching interests center on dynamics, control and optimization of electrical energy systems.