Vulnerability Analysis of Smart Grids to GPS Spoofing

Abstract

Sensors such as phasor measurement units (PMUs) endowed with GPS receivers are ubiquitously installed providing real-time grid visibility. A number of PMUs can cooperatively enable state estimation routines. However, GPS spoofing attacks can notably alter the PMU measurements, mislead the network operator, and drastically impact subsequent corrective control actions. Leveraging a novel measurement model that explicitly accounts for the GPS spoofing attacks, this paper formulates an optimization problem to identify the most vulnerable PMUs in the network. A greedy algorithm is developed to solve the aforementioned problem. Furthermore, the paper develops a computationally efficient alternating minimization algorithm for joint state estimation and attack reconstruction. Numerical tests on IEEE benchmark networks validate the developed methods.

Attack Identification and Correction for PMU GPS Spoofing in Unbalanced Distribution Systems

“…The proposed method enables the correction of multiple GSAs in unbalanced distribution systems, while [11] - [13] are applied to transmission systems. As mentioned in Introduction, the existing studies on the cyber-attacks in transmission systems cannot be trivially extended to distribution systems.…”

“…Hence, the GSA on a PMU affects the three-phase voltage and currents measured by the attacked PMU with the same phase shift [13].…”

“…Such a probing signal leads to a larger measurement residual, and therefore, ∆ > 2 is required. , which is not difficult to achieve, since these phase shifts are usually significant [11], [13]. Typical spoofed phase angles such as 52°, 60° and 70° are reported in [5], [8], and [9].…”

“…Recent studies on GSAs mainly focus on two issues: (1) the impacts and analysis of GSAs (e.g., [5], [8], and [9]), and (2) detection and correction for GSAs in transmission systems (e.g., [10]- [13]). For example, a detection mechanism for multiple spoofing attacks is proposed from a physical perspective in [10].…”

Digital Electrical Substation Communications Based on Deterministic Time-Sensitive Networking Over Ethernet

“…In the context of Smart Grid, gPTP timing can provide synchronization on the order of tens of nanoseconds (experiment V-C1) for the substation equipment, far exceeding the ∼1 µs specification of IEC 61850 Part 5 [11]. As this reference will be distributed over Ethernet links, it is a safer alternative than the GPSbased systems that synchronize Phasor Measurement Units in some substations, adding protection against accidental or intentional GPS malfunction [12]. [16], [17], which disseminate these parameters throughout the system.…”