Moving-Target Defense for Detecting Coordinated Cyber-Physical Attacks in Power Grids via a Modified Sensor Measurements Expression

Abstract

This paper proposes a modified sensor measurement expression for moving target defense (MTD) method to detect coordinated cyber-physical attacks(CCPAs). As a new type of attack, CCPAs are considerably harmful. Through elaborately designing a coordinated cyber-attack, the negative effects of a physical attack on sensor measurements are masked and can bypass bad data detector(BDD). MTD strategy can actively perturb transmission lines’ reactances, which makes the knowledge of a power grid grasped by attackers invalid. In the paper, first, based on undetectable CCPAs production principle before MTD activation, the undetectable CCPAs’ production mechanism is analyzed after MTD activation; and then a modified sensor measurement expression for detecting CCPAs is provided after MTD activation. Extensive simulations implemented on IEEE 14-bus, IEEE 30-bus and IEEE 118-bus systems verify the simplicity and efficiency of the approach.