Reliability impacts from cyber attack on electric power systems

Abstract

The level of risk from cyber attack against control systems used in the electrical grid is uncertain. At various times, the likelihood of attack, the availability of opportunity in the form of cyber vulnerabilities, the impact to the power system, and the consequences have all been debated at length. This research addresses the issue of grid impacts from cyber attack. (The remaining issues are not considered; as such, intent and opportunity are assumed.) One significant part of the analysis is the development of a Cyber-to-Physical (C2P) bridge, which links cyber attack vectors to resulting events in the Electric Power Grid (EPG); for example, a successful cyber penetration of a protective relay in a substation may result in an unplanned breaker trip. The analysis approach calculates an estimate of the grid performance degradation of cyber attacks, as they affect system reliability. The work models cyber attack in terms of unexpected outages to grid equipment; this way, for a given probability of cyber attack, the additional degradation to system reliability that results may be quantitatively determined. After simulation, the difference in reliability (with or without cyber attack) is the average grid impact for a given attack probability. This report includes tests for the algorithm to show its efficacy and versatility for analysis of various cyber impacts. With refinement, the proposed approach could be used as an important tool for control system risk analysis.