Cyber security study for power systems under denial of service attacks

An open communication infrastructure is used to support data transmission in a modern deregulated power system, it makes communication channels vulnerable to cyber-attacks and the reliability of the power system is affected. This paper studies the load frequency control of a one area power system under denial-of-service attacks. First, the state model of the closed-loop power system for one area is formulated, where the time delay of the communication channels is taken into account. Secondly, an event-triggering control mechanism is integrated with the load frequency control scheme of the power system; it can effectively improve the utilization of communication channels for an area control error transmission. Then, by utilizing the average dwell time design approach, the exponential stability criteria and the good stability effect can be obtained for a one area power system with an event-triggered load frequency control scheme under denial-of-service attacks, if an appropriate rate is chosen for the allowable denial-of-service attacks duration when the entire system running, and if the time delay margin can be acquired for these criteria. Finally, an example shows that the dynamics of a one area power system are compared with different denial-of-service attacks scenarios.