Preventing Time-Synchronization Attacks on Synchrophasor Measurements of Wide-Area Damping Controllers

The advent of system-wide synchrophasor measurement technologies has empowered modern power grids to deal with large-scale stability issues through the development of wide-area damping controllers (WADCs). The performance of WADCs, however, hugely depends on the accuracy and authenticity of time-synchronization mechanisms, which can be compromised by time-synchronization attacks (TSAs). Aiming to counter such attacks, this article first develops a TSA model that leverages the susceptibility in the time-alignment strategies employed by phasor data concentrators (PDCs) to collect and process the set of phasor measurement unit (PMU) data. From the attacker’s perspective, targeted PMUs and manipulation of their associated timestamps are obtained using a stochastic mixed-integer linear (MIL) model. The presented attack model hinders WADCs from observing dominant low-damping oscillation (DLO) modes by launching an optimal TSA on PMUs. Afterward, to counter the developed TSA, this article proposes a preventive countermeasure by co-optimizing the PMU-PDC data forwarding tree and PDC buffer waiting time. In this countermeasure, the operator’s defense decision variables, that is, the PMU-PDC data forwarding tree and PDC buffer waiting time, are co-optimized to maximize WADC’s modal observability under TSA, while satisfying the latency requirements. The attacker–operator interaction is modeled as a new min-max robust optimization model and solved using a column and constraint generation (C&CG) approach. The impacts of the presented attack and the effectiveness of the prevention countermeasure are evaluated on Two-area Kundur and New England 39-Bus test systems.