Mitigation of Cyber-Attacks on Wide-Area Under-Frequency Load-Shedding Schemes

Abstract

This paper investigates the problem of cyber-attacks on WAUFLS, as these schemes are critical to maintaining power systems stability. First, we perform a detailed analysis on existing WAUFLS schemes and show that an adversary can launch a FDI cyberattack by manipulating the frequency measurements or Power Flow Measurements (PFMs), which may lead to system losses, unnecessary shedding of important loads, and system-wide blackout. Second, to address this vulnerability, we propose a novel UF-RMMS scheme to protect against FDI cyber-attacks. The disturbance calculation and load shedding process in UF-RMMS are based on reliable system states, obtained using a proposed data-classification method on the PFMs that secures the state estimation operation. These reliable states are then used to perform the power flow in order to calculate the power mismatch. The calculated magnitude of disturbance, as well as the obtained system states, are used to decide on the amount and locations of the load-shedding. We validate the effectiveness and accuracy of UF-RMMS by conducting extensive simulation on the IEEE-39 bus New England system using PSCAD/EMTDC. The results confirm the proposed scheme’s capabilities in evaluating system disturbance and performing load-shedding, thus protecting the system during under-frequency conditions, and demonstrate its robustness against FDI attacks.