PMUs provide time-synchronized measurements at select, remote points on the grid. These time-synchronized measurements provide utilities with much better situational awareness of the grid’s current state—offering grid operators a means for better decision making and enabling new automated control strategies. Essentially, PMUs are moving the power industry from grid state estimation to real-time state measurement. PMUs not only promise better control and increased reliability in real-time applications but can provide supplemental information as inputs to static state-estimation tools to increase their accuracy and reliability.
On the other hand, PMUs can also offer adversaries more avenues of attack. Using PMUs for automated control, for example, enables fast, real-time corrective actions to occur, but these control schemes rely on very accurate timing—and GPS time sources have proven subvertable, which could result in inappropriate control actions. Additionally, real-time state measurement of the grid might provide valuable information for adversaries to better time attacks during periods of poor grid health, increasing the probability of success or possibly increasing an attack’s consequences (e.g., more customers without power).