Power Grid State Estimation under General Cyber-Physical Attacks

TL;DR

This paper addresses the challenge of accurately estimating the state of power grids under complex cyber-physical attacks, including grid partitioning, by proposing a linear programming approach that improves link failure detection.

Contribution

It extends existing methods to handle grid disconnections and introduces a new LP-based algorithm for link recovery without prior knowledge of post-attack power injections.

Findings

High accuracy in localizing failed links with known phase angles

The proposed method works under grid partition scenarios

Algorithm performs well on the Polish power grid model

Abstract

Effective defense against cyber-physical attacks in power grid requires the capability of accurate damage assessment within the attacked area. While some solutions have been proposed to recover the phase angles and the link status (i.e., breaker status) within the attacked area, existing solutions made the limiting assumption that the grid stays connected after the attack. To fill this gap, we study the problem of recovering the phase angles and the link status under a general cyber-physical attack that may partition the grid into islands. To this end, we (i) show that the existing solutions and recovery conditions still hold if the post-attack power injections in the attacked area are known, and (ii) propose a linear programming-based algorithm that can perfectly recover the link status under certain conditions even if the post-attack power injections are unknown. Our numerical evaluations based on the Polish power grid demonstrate that the proposed algorithm is highly accurate in localizing failed links once the phase angles are known.