Vulnerability Assessment for Coupled Network Consisting of Power Grid and EV Traffic Network

With the rapid development of EV in the transportation system, its increasing influence on the power system has attracted more and more attention in recent years. Under such a background, a virtual EV energy network (VEEN) in traffic level coupled with the corresponding power grid is formed in this paper, considering the energy carried by EVs in a specified area as a virtual node. To further identify the vulnerable components in the coupled energy network, a hybrid approach based on a complex network (CN) is presented. A hybrid power transfer distribution factor (HPTDF) is proposed for the coupled energy network considering the variation of VEENs over time. Then, the line betweenness and the modified time-varying coupling net-ability are designed to evaluate the vulnerability of the coupled network. Furthermore, to demonstrate the applicability of the proposed models, three case studies are performed on the 39-bus IEEE power network coupled with a 19-node VEEN. The simulation result verifies the effectiveness of the method in terms of identifying the critical lines in a coupled energy network, and a vulnerability assessment progress by designing a slow-fast dynamic cascade failure simulator in this paper verifies that a VEEN layer coupling defense strategy can decrease the vulnerability of a power grid layer under random attacks.