Optimizing the robustness of electrical power systems against cascading failures
Abstract
Electrical power systems are one of the most important infrastructures that support our society. However, their vulnerabilities have raised great concern recently due to several largescale blackouts around the world. In this paper, we investigate the robustness of power systems against cascading failures initiated by a random attack. This is done under a simple yet useful model based on global and equal redistribution of load upon failures. We provide a comprehensive understanding of system robustness under this model by (i) deriving an expression for the final system size as a function of the size of initial attacks; (ii) deriving the critical attack size after which system breaks down completely; (iii) showing that complete system breakdown takes place through a firstorder (i.e., discontinuous) transition in terms of the attack size; and (iv) establishing the optimal loadcapacity distribution that maximizes robustness. In particular, we show that robustness is maximized when the difference between the capacity and initial load is the same for all lines; i.e., when all lines have the same redundant space regardless of their initial load. This is in contrast with the intuitive and commonly used setting where capacity of a line is a fixed factor of its initial load.
 Publication:

Scientific Reports
 Pub Date:
 June 2016
 DOI:
 10.1038/srep27625
 arXiv:
 arXiv:1602.07763
 Bibcode:
 2016NatSR...627625Z
 Keywords:

 Physics  Physics and Society;
 Computer Science  Social and Information Networks;
 Physics  Data Analysis;
 Statistics and Probability
 EPrint:
 18 pages including 2 pages of supplementary file, 5 figures