A novel cyber resilience method for frequency control in power systems considering nonlinearities and practical challenges

Contemporary power systems are threatened by cyberattacks as a result of their interactions with information and communication technologies (ICT). Load frequency control (LFC) system is a fundamental power system application whose role is to maintain the power balance of the grid by sensing frequency deviations and properly regulating the output of the generators. Due to its dependence on ICT, the LFC is directly exposed to digital threats. This paper introduces a novel method for the estimation and mitigation of False Data Injection Attacks (FDIAs) to address cyber threats against LFC. The proposed method utilizes an innovative sliding mode technique to approximate the launched FDIAs against the LFC. Then, the estimated attack vector is added to the control loop to eliminate the cyberattack impact on LFC, forming an attack-resilient control strategy. This approach is robust against external system disturbances as it is designed to be completely decoupled from them. For experimental validation, several real-world power system features are implemented, including nonlinearities, network delays, diverse types of tie-lines and multiple topologies, and a Hardware-in-the-Loop testbed is developed for real-time testing. The results confirm the effectiveness, the feasibility and the scalability of the proposed defense method along with its superiority compared to other similar techniques.