Attack Detection and Mitigation Scheme of Load Frequency Control Systems Against False Data Injection Attacks

Load frequency control (LFC) of modern power systems depends on open communication networks to transmit measurement/control signals, which may make the LFC scheme vulnerable to cyberattacks. Therefore, it is necessary to ensure the resilience of LFC systems against cyberattacks so as to detect the attack and maintain the stable operation of the system during the attack. This article aims to investigate the attack detection and mitigation scheme of LFC systems against false data injection attacks. A model-based unknown input observer (UIO) is designed to simultaneously estimate the system state and attack signal based on load prediction, where the attack estimation is utilized to achieve real-time attack detection. Moreover, we present a sufficient and necessary condition for the existence of the UIO and a design method of the UIO based on linear matrix inequalities. Based on the attack estimation, a resilient LFC scheme is proposed to mitigate the attack impact and restore the frequency and tie-line power within an accepted range during the attack. Finally, case studies are undertaken by the IEEE 9- and 39-bus test systems to show the effectiveness of the proposed scheme.