Ranking Power System States based on Vulnerability to False Data Injection

Wide area applications in modern day power systems use global measurements transmitted over communication channels. Possibility of data corruption at sensor level or in the communication network renders these applications vulnerable to cyber attacks. This paper provides a metric to the vulnerability of power system state estimation to false data injection. Vulnerability index of a state has been quantified as the minimum number of measurements that an adversary would need to corrupt to ensure manipulation of its estimate without being detected. A methodology for computing this vulnerability is presented in the paper. The paper classifies the states depending on their relative vulnerability and proposes an order of ranking. Ranking of these states is useful to the system operator if one decides to selectively protect few states in a resource limited condition. The proposed methodology is simulated on the IEEE 14 bus test system and also on 765 kV and 400 kV subsystems of the Western Region of Indian Grid and the results are presented.