Research On The Robustness Of Cyber Physical Power System Under Cyber Attack

Driven by various factors such as energy transformation,environmental protection requirements and technological progress,the traditional power system is moving towards intelligent,distributed,renewable energy and other diversified directions,and gradually develops into a new type of power system-cyber physical power system(CPPS).Through advanced information and communication technology,CPPS has realized the intelligence,efficiency,security and reliability of the power system,but it has also brought a series of cyber security problems.Therefore,studying the robustness of CPPS under cyber attack is of great significance for defending and responding to existing,even new and unknown cyber attack,and maintaining the safe and stable operation of the system.Based on the above background,this paper takes CPPS as the research object,and carries out the research on modeling technology of CPPS,system robustness analysis and optimization under cyber attack.The main work and conclusions include the following three aspects:(1)Model analysis and establishment of CPPS.First,based on the basic structure of CPPS and its internal cyber-physical interaction mechanism,CPPS is simplified into a four-layer model framework,and the modeling process is divided into power physical layer,power cyber layer and CPPS integrated model.On this basis,considering the DC power flow distribution and networking characteristics of the system,two sub-network layer models are constructed respectively.Then,according to the actual interaction process of the system,the CPPS integrated mathematical model is constructed,and its internal correlation is described quantitatively.(2)Robustness analysis of CPPS under cyber attack.First of all,according to the cyber attack principle of CPPS,it is classified and divided into four attack schemes according to its impact on the system.Based on the cross-layer cascading failure process of the system under the cyber attack environment,taking four standard power node systems as examples,the multiindex fusion robustness evaluation method is adopted to simulate the robustness analysis of CPPS under cyber attack.After comparing the results,it is concluded that even a small cyber attack will seriously damage the robustness of CPPS.In addition,the cyber attack effects on the process of issuing control commands is particularly obvious.(3)Robustness optimization of CPPS under cyber attack.First,based on the qualitative and quantitative analysis of the robustness of CPPS from cyber attack in the previous article,a robust optimization strategy for identifying and protecting key nodes is proposed.Then,considering six different topological characteristic indexes and one improved functional index,a comprehensive evaluation index for key nodes is proposed.Then,from the perspective of equivalent deliberate cyber attack,verification and comparison simulations are carried out on IEEE 39 and IEEE 118 bus systems,and the key node sets in CPPS are obtained,which will provide a more specific and comprehensive robustness optimization strategy for the future reference.