The advanced electric power grid is a cyber-physical system comprised of physical components, such as transmission lines and generators, and a network of embedded systems deployed for their cyber control. The objective of this paper is to qualitatively and quantitatively analyze the reliability of this cyber-physical system. The original contribution of the approach lies in the scope of failures analyzed, which crosses the cyber-physical boundary by investigating physical manifestations of failures in cyber control. As an example of power electronics deployed to enhance and control the operation of the grid, we study Flexible AC Transmission System (FACTS) devices, which are used to alter the flow of power on specific transmission lines. Through prudent fault injection, we enumerate the failure modes of FACTS devices, as triggered by their embedded software, and evaluate their effect on the reliability of the device and the reliability of the power grid on which they are deployed. The IEEE118 bus system is used as our case study, where the physical infrastructure is supplemented with seven FACTS devices to prevent the occurrence of four previously documented potential cascading failures.

Meeting Name

28th International Conference on Computer Safety, Reliability, and Security (2009: Sep. 15-18, Hamburg, Germany)


Electrical and Computer Engineering

Second Department

Computer Science


This is a post-peer-review, pre-copyedit version of an article published in Lecture Notes in Computer Science: Computer Safety, Reliability, and Security. The final authenticated version is available online.

Keywords and Phrases

Bus Systems; Cascading Failures; Cyber-Physical; Cyber-Physical Systems; Electric Power Grids; FACTS Devices; Failure Propagation; Fault Injection; Flexible AC Transmission System; Physical Components; Power Grid; Power Grids; Transmission Line; Electric Impedance; Electric Lines; Electric Power Measurement; Electric Power Transmission; Electric Power Transmission Networks; Embedded Software; Embedded Systems; Failure Analysis; Power Converters; Power Electronics; Power Generation; Quality Assurance; Software Reliability; Software Testing; Transmission Line Theory; Reliability Analysis

International Standard Book Number (ISBN)

9783642044670; 9783642044687

International Standard Serial Number (ISSN)

0302-9743; 1611-3349

Document Type

Article - Conference proceedings

Document Version

Accepted Manuscript

File Type





© 2009 Springer Verlag, All rights reserved.

Publication Date

01 Sep 2009