The Research On Intrusion Detection And Risk Assessment Of False Data In Power CPS

Smart Grid(SG)is a Cyber-Physical System(CPS)which integrates sensing,communication,computing,decision-making and control based on traditional power grids.Because of its open communication environment and complex Information-Physical coupling,network security has become an important factor affecting the safe and stable operation of smart grid.Among them,False Date Injection Attack(FDIA)is a typical network attack that destroys data integrity in smart grid.If FDIA fails to detect in time,it will interfere with control decisions by hijacking physical equipment or attacking network transmission lines,which may lead to power network failure,or even cascade failure.Therefore,it is of great significance to study the method of false data intrusion detection in smart grids and the risk assessment of cascade faults caused by FDIA.This paper studies the detection method of FDIA based on physical information in wide-area monitoring system and evaluates the risk that FDIA may cause cascade failure of power network system.The main work of this paper is as follows:Aiming at the problem of real-time effective detection of false data attacks in smart grid,this paper proposes an intrusion detection method for false data based on physical information.Node Voltage Stability Index(NVSI)is calculated by using synchronous phasor measurement unit to collect real-time measurement information.If there are abnonnal NVSI values in grid nodes,outlier-based detection algorithm is used to detect attacks that can break the stability of the loop system and detect the attacked nodes.If there are no abnormal NVSI values in grid nodes,vulnerable nodes are screened according to the difference of NVSI values of nodes in time,and then the attacked nodes are detected cooperatively by using physical rules for the screened nodes.Experiments show that the proposed method can detect the attacked nodes faster than other methods and improve the detection accuracy.In view of the risk that FDIA may cause cascading failure in power network,this paper proposes a cascade fault risk assessment method based on FDIA.This method analyses the risk of cascade faults in power network after network nodes in power CPS information network are attacked by false data from the attacker's point of view.Firstly,the network node risk assessment model based on cloud model is used to assess the network node risk and get the attacked risk value.Then,the coupling relationship between the information network and the physical network is considered.Finally,the risk value of cascade failure is calculated according to the probability of cascade failure of power network caused by the destruction of physical lines.Through this method,the risk assessment value of cascading faults of power network can be obtained when false data attack information network nodes.