Cascading failure in coupled networks of transportation and power grid

The large-scale application of electric vehicles (EVs) makes the power grid and transportation network deeply coupled, resulting in the propagation of random disturbances and failures between the two systems. This paper proposes an analysis method of cascading failure in the coupled networks of transportation networks and power grids. The cascading failure model of a power grid with large-scale EV charging loads is established by using a direct current power flow based on the frequency response (DFR). The behavior characteristics of EVs and transportation states under failure conditions are analyzed by combining the travel decisions of users with the traffic network equilibrium. Considering the coupling relationship between the power grid and transportation networks at charging station nodes, the load–capacity model is adopted to describe the propagation of failures between the two networks. Finally, the propagation characteristics of failures considering the primary frequency modulation and rationality degree of EVs are simulated and analyzed. The simulation results show that the application of EVs makes the power grid and transportation mutually dependent, and the primary frequency modulation characteristic and bounded rationality of EVs can weaken the effect of cascading failure in the coupled networks.