Research On Resilient Load Frequency Control Of Power Cyber Physics System

Smart grids use advanced communication and control technologies to achieve a deep integration of power physical space and cyber space,and to achieve a secure,reliable,economic,and environmentally friendly power grid.With the increasing dependence of the power system on advanced communication technologies,the power system has gradually developed into a cyber physical system.However,while the use of advanced communication networks brings convenience to the monitoring and regulation of the power system,its highly open and interconnected features make the system certain security loopholes in data collection,communication,and authentication.At the same time,widely distributed intelligent terminals will generate massive monitoring data,which will cause greater bandwidth pressure on the information communication network.These factors have brought great hidden dangers to the safe and stable operation of the power grid,ranging from power grid instability and equipment damage in the worst case to a large-scale collapse of the power grid.Based on the above background,this paper focuses on issues such as the modeling of load frequency control(LFC)systems under common cyber attack modes,cyber attacks,and event-triggered communication mechanisms,stability criterion derivation,and resilient controller design.The main works of the paper are as follows:(1)Consider the problem that a multi-area LFC system is subject to a periodic denial-of-service(Do S)attack and the communication channel data transmission process is blocked.Firstly,the periodic Do S attack mode and its possible impact on the system are analyzed,and then the LFC system model taking into account the Do S attack is constructed,the system stability criteria is deduced by using the Lyapunov theory and linear matrix inequalities.Moreover,the resilient controller is designed based on the stability criteria.Finally,the effectiveness of the designed controller is verified by a numerical example,and the dynamic performance of the system under different Do S attack strengths is compared.(2)Consider the problem of resilient load frequency control under the hybrid cyber attack mode of denial of service attack and deception attack on multi-region LFC system.First of all,the possible impact of a hybrid cyber attack on the generation side of the power system on the grid frequency is analyzed.Then,a multi-area load frequency control switching system model considering hybrid cyber attacks is constructed.Then,using the Lyapunov theory and linear matrix inequality technology,the exponential mean square stability of the switching system is analyzed.Further,based on the stability criterion,the design of the resilient controller is carried out.Finally,a two-area power system simulation was selected to verify the effectiveness of the controller and the robustness to uncertain parameters.(3)Consider the limited bandwidth of the communication network of the multi-area interconnected LFC system and the periodic Do S attacks,the joint design problem of the resilient event-triggered mechanism and the load frequency controller under the denial of service attack is studied.First,the Do S attack parameters are known.In this case,a Resilient Event-Triggered Communication(RETC)mechanism is proposed,which can alleviate the pressure of communication bandwidth and eliminate the influence of denial of service attacks.Then,a delay switching system model of load frequency control based on RETC mechanism and Do S attack is constructed.Then,the switching system stability criteria is deduced by using the Lyapunov theory,and a co-design method for triggered parameter and controller is designed.Finally,a two-area interconnected power system simulation validates the effectiveness of the proposed method.