Research On Load Frequency Control Of Multi-area Interconnected Power System Under Denial-of-service Attacks

Load Frequency Control(LFC),as an important part of the power system,its main control goal is to ensure that the frequency of the whole power system is stable at the set value by keeping the balance between the power generated and the power consumed by the load.With the development of multi-region interconnected power system,when the information transmission layer is damaged,the system stability will be damaged.In various types of network attacks,denial-of-service(DoS)attacks,which prevent communication between information layers of a system,clog the communication network,disable control functions and eventually destabilize the power system.Therefore,it is very important to ensure the stable operation of power system under DoS attacks.This paper mainly studies the possible interference of load frequency control of multi-region interconnected power system,the increase of communication data volume caused by the continuous expansion of interconnected power system and the possible DoS attack.The main contents are as follows:(1)The mathematical model of load frequency control in multi-region interconnected power system is established,the model of single region frequency modulation unit is introduced,and the governor,prime mover,generator-load and contact line are briefly described.(2)A simple controller is designed to solve the network security problem of multi-area interconnected power systems under denial-of-service attacks of measurement channels and control channels.The frequency and duration of DoS attacks are given to maintain the input-state stability of the closed-loop system.In order to realize the stability of input state under controlled DoS attacks,a suitable sampling mechanism is determined.Achieve the balance between system performance and communication resources.(3)In order to solve the problem of unstable load frequency control of multiregion interconnected power system caused by DoS attack in measurement channel,a scheme of elastic event triggering mechanism and controller is applied.An observerbased periodic event triggering control framework is constructed to limit the influence of interference and noise.Then,the input-state stability of the closed-loop system is proved according to the maximum transmission time interval.The frequency and duration of DoS attacks are maximized without loss of system robustness.On this basis,an elastic LFC scheme for double-loop communication channel is proposed.Finally,the effectiveness of the LFC scheme against DoS attacks is verified by an example.In this paper,the load frequency of multi-area interconnected power system under DoS attack is controlled safely.Firstly,the measuring channel and control channel are considered to join DoS attack,and the controller and sampling mechanism are designed to maintain the stability of the system.Then,only DoS attacks are added into the measurement channel,event triggering mechanism and state observer are designed to reduce the influence brought by interference.When the attack signal cannot be successfully transmitted,the state value is predicted by the predictor,so that the system can achieve stability.