GPS Spoofing Effect on Phase Angle Monitoring and Control in an RTDS-based Hardware-InThe-Loop Environment

In recent years, Cyber-Physical System (CPS) applications have been extensively utilized in the electric power grid to enable wide-area protection, control, and monitoring of power systems. Many of these applications in a smart grid CPS depend on reliable time synchronization. For example, synchrophasor data from geographically distributed Phasor Measurement Units (PMU) utilize Global Positioning System (GPS) for precise timing. However, these units are exposed to GPS time spoofing attacks that can lead to inaccurate monitoring and trigger unnecessary, and possibly destabilizing, remedial control actions. In this paper, we develop an end-to-end case study demonstrating the effect of GPS spoofing attacks on the phase angle monitoring and control functions of a PMU-based load shedding scheme. The evaluation of our attack strategy is performed in a Hardware-In-The-Loop Real Time Digital Simulator-enabled power system testbed.