Assessing Power System State Estimation Accuracy with GPS-Spoofed PMU Measurements

Power grids have evolved into cyber-networks equipped with high speed communications and advanced sensors. While this evolution has been monumental, the risk of cyber-attacks is growing. In grids, phasor measurement units (PMU) -equipped with GPS receivers-are now ubiquitously installed in widespread locations, while providing real time grid-visibility. Cooperatively, limited number of PMUs can enable state estimation (SE) routines. However, PMU measurements can be notably altered via a GPS spoofing attack and consequently causing a misleading depiction of the physical status of the system. Here, we evaluate the impact of a GPS time-synchronization attack on the grid's SE routines. Statistical information regarding the attacked estimates are derived with relevance to the actual state of the system. We also investigate bounds on the estimation bias introduced by the aforementioned attacks. Numerical examples are included to support the developed methods.