Description:

Say No to Blackouts: Identifying the Black Sheep in the Power Grid

Wednesdays@NICO Seminar | 12:00 - 1:00 PM, March 4, 2015 | Chambers Hall, Lower Level

Yang Yang, PhD Candidate, Physics & Astronomy, Weinberg College of Arts & Sciences

Abstract
Large-scale power outages, such as the 2003 Northeast Blackout, can inflict billions of dollars in economic damage to society. Such outages are caused by cascading failures, in which a relatively small local disturbance triggers a sequence of component failures and cause global power flow rearrangements that disconnect parts of the network. Despite much effort on analyzing the origins, failure sequences, and probabilities of individual events, the dynamics of such cascading failures are still poorly understood. In this talk I will introduce a realistic model for the propagation of line failures in power grids based on the physics of power flow distribution and the temperature response of overloaded transmission lines. Focusing on the North American power grid, I will show that the failures in all simulated cascades are constrained to a surprisingly small subset of the power lines and that the failures are strongly correlated. By capturing this correlation, we can predict the probability distribution of cascades sizes using a simple statistical model. Aside from their implications for the understanding of failure propagation in real systems, these results may help improve design strategies aimed to strengthen the power grid and prevent large blackouts.

Bio
Yang is a Ph.D. candidate in the Department of Physics and Astronomy at Northwestern University. Her research focuses on the theory of complex networks and its applications to power grids. It combines methods from statistical physics and dynamical systems with computer simulations and empirical analyses. She has a bachelor’s degree in mathematics and physics from Tsinghua University.