Online Risk-Based Security Assessment

N. M. Ni, J. D. McCalley, V. Vittal, T. Tayyib

Research output: Contribution to journalReview articlepeer-review

17 Scopus citations


The work was motivated by a perceived increase in the frequency at which power system operators are encountering high stress in bulk transmission systems and the corresponding need to improve security monitoring of these networks. Online risk-based security assessment provides rapid online quantification of the security level associated with an existing or forecasted operating condition. One major advantage of this approach over deterministic online security assessment is that it condenses contingency likelihood and severity into indices that reflect probabilistic risk. Use of these indices in control room decision-making leads to increased understanding of potential network problems, including overload, cascading overload, low voltages, and voltage instability, resulting in improved security related decision-making. Test results on large-scale transmission models retrieved from the energy management system of a U.S. utility company are described.

Original languageEnglish (US)
Pages (from-to)59
Number of pages1
JournalIEEE Power Engineering Review
Issue number11
StatePublished - 2002
Externally publishedYes


  • Security assessment
  • cascading
  • control center
  • decision-making
  • operations
  • overload
  • probabilistic risk
  • uncertainty
  • voltage instability

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


Dive into the research topics of 'Online Risk-Based Security Assessment'. Together they form a unique fingerprint.

Cite this