Research On The Security Defense Of Distribution Network Against False Data Injection

Distribution network plays a vital role between the users and the substation system.It's safe and stable operation can provide guarantee for the development of national economy,social stability and peoples living needs.At present,the rapid development of information technology,has been widely used in the distribution system,and the distribution network to constitute the cyber physical distribution system(CPDS),the network security problem is increasingly serious.false data attack(FDA)is a new type of network attack which is specially used to estimate the result of system state.Therefore,it is of far-reaching practical significance to study the FDA power distribution system security defense problem.Based on the above background,this paper mainly focuses on the distribution system as the research object,aiming at the serious threat caused by the FDA which belongs to integrity attack.By analyzing the action mechanism of FDA in the system,a detection method based on adaptive Kalman filter algorithm was proposed.At the same time,the defense strategy of distribution network based on game theory is designed and implemented,which provides reliable theoretical support for deeply integrated CPDS to avoid the threat of FDA and operate safely and stably.The specific research contents can be summarized as follows:Firstly,the current situation of FDA in distribution network is analyzed.FDA is through phasor measurement unit(PMU),remote terminal unit(RTU)communication links such as the invasion of success into the system,the main role in state estimation link of bad data detection and induced its estimate deviation from normal lead to staff to make the error control decisions.Through the network attack explains how its far-reaching influence on the system function.Second,according to the principle and action mechanism of FDA,a detection architecture of false data attack on power grid is constructed,and a non-negative definite adaptive Kalman filter algorithm for FDA detection is proposed.The filtering algorithm solves the problem of filtering divergence by estimating the state quantity of the system,so as to accurately detect the false data in the power system.Through the simulation of the detection algorithm proposed in this paper,the results verify that the algorithm not only guarantees the filter stability,but also improves the computation speed of attack detection.Third,after the successful detection of FDA in the power distribution system,the defense strategy of FDA was studied.In order to solve the optimal defense strategy of power distribution system after being invaded by FDA,this paper USES the idea of game theory to establish the two-layer model of multi-objective optimization,and obtains the Nash equilibrium of the game model through Pareto optimization.In this paper,it is assumed that only one branch and one information node are attacked,and from the standpoint of the defender,the minimum load loss and the best defense effect are obtained through layered calculation in this two-layer model.The feasibility and effectiveness of the game model are verified in the IEEE14 node distribution system.