Research On Power-communication Coupled Network Model And Vulnerability

With the continuous improvement of power grid intelligence and the highspeed evolution of information and communication technology,smart grid has gradually developed into a power-communication coupled network with deep coupling by power grid and power communication network.The communication network provides efficient and reliable information acquisition and control capability for the power grid.However,its faults may also affect the power system through the coupling relationship,and even trigger cascading failures in the coupled network.Therefore,the study of power-communication coupled network cascade failures model,critical nodes identification and its protection strategy can effectively improve the coupled network cascade failures risk and reduce the network vulnerability,which is important for the safe and stable operation of smart grid.The primary research works of this thesis are as follows:Firstly,based on the characteristics and interaction mechanism of power communication network depending on power network construction,a powercommunication coupled network model is constructed;and based on the coupled network model,a power-communication coupled network cascading failure model is constructed by considering the change of controllability of its coupled power nodes due to the failure of communication nodes and simulating the N-1 failure of grid nodes.Then,the importance of power nodes is calculated based on the power transfer distribution factor.and the importance of power services carried by their coupled communication nodes is weighted,and then a critical communication nodes identification algorithm considering power services distribution and communication network topology is proposed.Using the IEEE 39-bus system and its coupled communication network as an example.the effectiveness of the algorithm is verified using load loss and service loss metrics.Finally.based on the critical communication nodes identification results.an attack and defense game model of the coupled power-communication network is constructed.and then a coupled network nodes protection strategy is proposed.The model quantifies the game process between the attacker and the protector with the goal of maximizing their own revenue under the situation that the attack target is unpredictable and the protection resources are relatively limited.And for the game process between the two players.the optimal protection policy of communication nodes is obtained by the improved firefly algorithm.Simulation experiments prove that the optimal protection strategy generated by the used method can reasonably allocate protection resources,reduce the vulnerability of the coupled network to malicious attacks,and maximize the safe and stable operation of the power-communication coupled network.