Research On Security Control For Power System Load Frequency Control Based On Event-Triggered Mechanism

At present,in the field of power system control analysis,in order to relieve the pressure of limited network bandwidth resources and improve data utilization,abundant analysis and research on the design of event-triggered control scheme have been done by scholars at home and abroad.However,considering the dual influence of communication delay and network security,the research on load frequency control of networked power systems based on such kinds of communication protocol needs to be further supplemented and enriched.Therefore,under the influence of multiple network constraints,this paper analyzes and synthesizes the load frequency control for power systems through different control methods,in the hope that the control strategy adopted can not only ensure the system stability under cyber-attacks,but also rationally utilize the limited network bandwidth resources.The specific research contents are described below:（1）Discuss the problem of designing the load frequency controller for one-area power system suffering from deception attacks on the basis of the event-based secure control scheme.Firstly,to alleviate the occurrence of congestion phenomenon in the bandwidth-limited communication network,an event-triggered control scheme is introduced into the sensor-to-controller channel.Subsequently,a mathematical model with regard to the event-triggered load frequency control is established where the Bernoulli distribution is utilized to describe the randomness of deception attacks.Then,in terms of Lyapunov-Krasovskii stability theory and an improved integral inequality technique,the stability conditions of the resulting system are deduced.Besides,the corresponding controller gain is gotten on the basis of appropriate matrix transformation techniques.Finally,the feasibility of our theoretical derivation is argued by the simulations of one-area load frequency control system.（2）Discuss the problem,for networked power systems suffering from energy-limited denial-of-service attacks,that a switching-like event-triggered load frequency control synthesizes a sliding mode control strategy.Considering the intermittent of the denial-of-service attacks with limited energy,a switching-like event-triggered control scheme is adopted so as to remedy the adverse effect of data losses brought by denial-of-service attacks.Furthermore,under the co-design of the switching-like event-triggered control scheme and sliding mode control strategy,the relevant sliding mode dynamics are established.Then,on the basis of the Lyapunov-Krasovskii stability theory,some stability criteria,ensuring that the resulting system can reach asymptotic stability together with L₂-L_∞performance,are deduced.Correspondingly,a switching-like event-triggered load frequency sliding mode control law,to achieve the ideal system performance while assuring the reachability of sliding surface,is designed by settling matrix convex optimization problems.Eventually,the applicability of the presented method is proven by the simulation of a two-area load frequency control system with corresponding simulation results.（3）Design a dynamic event-triggered H_∞load frequency controller for multi-area power systems affected by false data-injection and denial-of-service attacks.A dynamic event-triggered control scheme,whose threshold parameter varies with objective system states,is employed to make rational use of limited network bandwidth resources while improving the efficiency of the data utilization.Meanwhile,taking the impacts of the aforementioned hybrid cyber-attacks into consideration,a relevant system model is established.Whereafter,several sufficient conditions,which can guarantee the exponential mean-square stability with a preset H_∞performance indexγof the studied system,are obtained through utilizing Lyapunov-Krasovskii stability theory.Additionally,the desired controller is designed via handling matrix convex optimization problems.Finally,the practicability of the proposed method is demonstrated by the simulations of a three-area load frequency control system.