Load frequency control (LFC) of modern power systems tends to employ open communication networks to transmit measurement/control signals, which makes the LFC scheme more vulnerable to random time delays and time-delay attacks (TDAs). In this article, a resilient and active time-delay-compensation-based LFC scheme is proposed to compensate the random time delays and TDAs. At first, a state observer is employed to estimate the state of the LFC system. Then, a networked predictive control method is used to predict the control signals of the system in future moments. Next, an evaluation and compensation scheme for random time delays and TDAs is constructed in the actuator side of the LFC scheme based on the updating period of the actuator and the timestamp technique. Due to the stochastic characteristics of the random time delays or TDAs, the stability condition of the proposed scheme is developed with the aid of the mean-square stability theory. Moreover, a dual-loop open communication is employed in the proposed scheme to improve the reliability and resilience. At last, simulation and experiment tests are undertaken to demonstrate the effectiveness of the proposed scheme.

Deception attacks that threaten communication networks will result in serious consequences ranging from the deterioration of damping performances to instability of power systems. To address this problem, this paper proposes a resilient wide-area damping control (RWADC) for inter-area oscillation based on a secure networked predictive control (SNPC), which is combined with information technology security system (ITSS) and the resilient control scheme based on networked predictive control (NPC). The ITSS including data encryption, data decryption and deception attack detection, is designed to guarantee data confidentiality, integrity, and authenticity. This security system is based on Data Encryption Standard (DES) and Message Digest Algorithm (MD5). The NPC part is used to provide optimal control sequences and compensate the impact of communication constraints and deception attacks, which includes modified generalized predictive control (MGPC), network delay compensator (NDC), and model identifier. Case studies are undertaken on the 16-machine 68-bus AC/DC hybrid power system. Simulation results show that the proposed RWADC can suppress inter-area oscillations, provide better damping performances than those of the conventional and robust WADC over different operating conditions and compensate adverse effects caused by deception attacks actively.

The wide-area damping controller (WADC) using the remote signals obtained from wide-area measurement system (WAMS) as input is an effective measure to suppress interarea oscillations. Once the input signal of WADC is threatened by false data injection attacks (FDIAs), its performance will be decreased dramatically. To address this problem, this article proposes a resilient adaptive wide-area damping control (RAWADC) framework combined with linear state estimator (LSE) and goal representation heuristic dynamic programming (GrHDP). The LSE is proposed and adopted as a preprocessor to detect and correct the attacked data. By detecting and correcting FDIA, the integrity of the WAMS measurement signal is guaranteed. The GrHDP algorithm is employed to design the WADC, which not only does not require a detailed mathematical model of the system but can also adapt to variations of the operating conditions. Simulation results of the 16-machine 68-bus system with voltage source converter based HVdc indicate that the RAWADC can suppress interarea oscillation effectively under a wide range of operating conditions, different FDIA types and measurement noise.

The growing risk of cyber attacks targeting wide-area damping control (WADC) has spawned much research on designing attack-resilient controllers recently. However, the issue of attack strength did not get enough attention so that most existing resilient WADCs may fail to defend strong attacks. To address this problem, this paper proposes a multiple-controller switching approach based resilient wide-area damping controller (MCS-RWADC) to suppress inter-area oscillations and mitigate strong attacks. It is inclusive of multiple secure networked prediction control based modules (SNPMs) and a switch-monitor module (MSM). The SNPM can detect attacks, differentiate attack strength and compensate for weak attacks. In terms of strong attacks, multiple SNPMs are implemented to work as backup and three operating states as well as the corresponding switching rules are designed to realize automatic switching among them. MSM is responsible for monitoring the states and directing the switching. Case studies are conducted on a 4-area 5-terminal voltage source converter-based multi-terminal high voltage direct current based offshore wind farm integration system. Simulation results verify MCS-RWADC cannot only suppress the inter-area oscillation but also handle the strong attacks under a wide range of operating conditions with various wind power output.