PI-Based Security Control Against Joint Sensor and Controller Attacks and Applications in Load Frequency Control

This article addresses the proportional-integral (PI)-based security control issue of large-scale systems subject to randomly occurring joint attacks. Specifically, the considered cyber-attacks could happen in both sensor-to-observer and controller-to-actuator, and only partial data of sensors and controllers are randomly tampered with by malicious attacks due to energy limits. For the addressed problem, an observer-based PI controller is constructed by resorting to the compensation of randomly occurring joint attacks, which are modeled by two diagonal matrices combined with a set of stochastic variables. A sufficient condition only dependent on the local system dynamics as well as the local interconnected matrices is derived in the framework of the input-to-state stability (ISS) theory, and the desired gains of both the controller and the observer are obtained by the cone complementarity linearization (CCL) algorithm. Benefiting from the element matrix inequality, the developed design scheme satisfies the scalability requirement. In the end, the simulation test based on IEEE 39-bus power systems is seriously used to demonstrate the validity of the proposed control scheme.