Research On Double Hidden Cascading Failure Model In Cyber Physical Power Grid

The modern power grid is closely integrating with sensing,communication and processing platforms,which is gradually becoming a complex cyber physical power grid(CPPG).The CPPG can timely obtain complete details of the entire system with large-scale sensory measurement systems and complex information networks.However,the communication networks also brings new uncertainties that unexpected malfunctions in the networks may result in the loss of visibility and controllability of the physical power grid,thus making the entire coupling network face great risks.Therefore,it’s of major therotical value to conduct coupling modeling and vulnerability analysis on the cyber physical power grid and propose corresponding protection strategies.The main research on the cyber physical power grid is as follows:Based on the complex network theory,considering the hidden faults of the physical power network and hidden faults of the cyber network,a dual-hidden cascading failure model of the cyber physical power grid is established.This model considers the hidden faults and islanding problems in the cyber network,and optimize the physical power network with the minimum load shedding.The critical interval(0.15-0.25)of the hidden failure rate of the cyber network nodes is obtained by the simulation of the model under the random attack of nodes.If the hidden failure rate is lower than the critical interval,the grid and the cyber network adopt the cyber network coupled mode with the scale-free structure,otherwise the cyber network coupled mode with the small world structure,which can improve the robustness of the cyber physical power grid,and reduce the risk of blackouts.In this paper,a dual-hidden cascading failure model of the cyber physical power grid based on the hidden failure probability prediction with Markov Model is proposed.The physical power network and the cyber network should adopt the coupling networking forms with different cyber network structures under different critical failure intervals of the cyber network nodes that is verified by the simulation of cascading failure of the coupling network.The vulnerability indexs of physical power network with the consideration of dual-hidden failure of the cyber physical power grid are proposed.Based on the proposed index,the simulation results show that the connectivity and load loss of the power grid coupling with cyber network with the small world structure are better than those of the power grid coupling with cyber network with the scale-free structure under targeted attack.The critical lines in the coupling network is different from the critical lines identified in a single network.Therefore,it is necessary to conduct the further research on the identification of critical lines in the coupling network,which can provide reference for the planning and protection of the power grid.