| The security control of power cyber-physical system(CPS)has been an important and popular research topic.Through the communication network,the power cyber-physical system connects the power equipment with the condition monitoring unit and the predictive control unit to form an integrated power network,which can realize the overall dispatching control of the power system.In recent years,switching systems have attracted attention due to their excellent modeling capabilities and have been widely applied in the modeling of many practical systems.This article cleverly applies the semi-Markov switching process to the modeling process of power cyber-physical systems under network attacks.Compared with the traditional Markov switching system,the dwell time of semi-Markov switching system obeys non exponential distribution,which relaxes the limitation of probability distribution and has a wider application space.At the same time,modern power cyber-physics systems transmit data through communication networks,and random network attacks have become an important factor affecting their safe and stable operation.At the same time,the random network attacks has become an important factor affecting its safe and stable operation.Network attacks such as denial of service attacks will block data transmission or cause waste of communication resources.Therefore,considering the random network attacks that occur during the operation of power cyber-physical systems has great research value.Based on this situation,this paper considers the security control of power cyber-physical switching system under network attacks.The main contents are as follows:1)The adaptive event-triggered control problem of power cyber-physical switching system with random denial-of-service(Do S)attacks is studied.Assuming that the attacker maliciously attacks the power communication network in the form of probability,the semi-Markov random switching process is introduced to model the power cyber-physical system.The transfer rate of semi-Markov switching model is time-varying and is related to the dwell time.Compared with the Markov switching system,it is less limited and more widely used.Firstly,an adaptive dynamic event-triggered control strategy is proposed for the power cyber-physical switching system under random denial-of-service attack,which can better meet the real-time requirements of the control system.Secondly,by selecting the appropriate Lyapunov function,the sufficient conditions for the stochastic stability of the system are given.Applying the adaptive event-triggered strategy,the power system can still maintain stability and security operation under random denial-of-service attack.Finally,the feasibility and superiority of the adaptive event-triggered control strategy are verified by the simulation experiment of the power system model.2)The load frequency control of multi-area interconnected power cyber-physical switching system under hybrid network attacks is studied.In this part,based on the single-area power system model,the multi-area interconnected power system is further studied.The multi-area interconnected power system needs to take the transmission power and frequency deviation of the interconnection lines in each area into account,so it needs to control the load frequency of the system.The load frequency control(LFC)takes the area control error(ACE)as the control signal to adjust the frequency,which plays a vital role in the research of power system.At the same time,on the basis of the first part of the study of the random denial-of-service attack on the power system,the situation of the system suffering from the random hybrid network attacks is discussed.First of all,a control strategy based on dynamic event-triggered mechanism is designed through area control error signal to eliminate the unstable factors brought to the interconnected power system by hybrid network attacks.Then,a sufficient condition for exponential mean square stability of power system is given by selecting appropriate Lyapunov function.Finally,the effectiveness of the load frequency control strategy is verified by the simulation experiment of the three-area interconnected power cyber-physical switching system model. |
