Model-Based Secure Load Frequency Control of Smart Grids Against Data Integrity Attack

In this paper, a cyber-physical digital signature creation method and a resilient load frequency control approach are proposed to improve the security of the existing SCADA protocols used in the load frequency control of interconnected power systems. In specific, the dynamic model of the power system is used to predict the future states of the system and the statistics of a number of future states are calculated and used as the dynamic hash to determine the integrity of the data communicated between remote telemetry units and the power system SCADA control center. The proposed algorithm has inherently the cyber-physical characteristics and enhanced robustness to collisions without adding a larger overhead to the message frame of the packets in current SCADA protocols. To compensate for the possible performance degradation and instability of the power system caused by corrupted data, a model-based resilient load frequency controller is designed for the smart grid. The maximum interval between two consecutive feedback updates in the model-based control scheme is obtained for securing the stability of the power system. The investigation of three types of integrity attacks on a two-area power system shows that the proposed model-based digital signature attack detection scheme is able to detect even a little inconsistency of the communicated data. By using the designed resilient load frequency controller, the stability and dynamic performance of the smart grid are guaranteed.