Interaction Mechanism Analysis of Rainstorm‑Induced Disruptive Incidents in Power and Transportation Systems

Electric vehicles (EVs) intricately link distribution systems (DS) and transportation systems (TS) into coupled systems. Under extreme weather conditions (EWCs), especially rainstorm‑induced urban flooding, disruptive incidents such as power shortages, road blockages and traffic congestion induce complex interactions between two systems, amplifying negative impacts on EV users and system operations. However, the mechanisms underlying these interactions remain insufficiently comprehended. Therefore, this paper analyzes the complex interactions of disruptive incidents between systems, revealing the cascading effects within systems under EWCs. First, an improved power support capacity (PSC) calculation algorithm is developed to reveal how disruptive incidents in TS affect DS, by quantifying the impact of user behaviors on load distribution of DS, with the behaviors arising from user demands shaped by TS states and EWCs. Similarly, user decision-making mechanisms are proposed based on improved cumulative prospect theory and integrated into dynamic traffic equilibrium models, revealing how DS influence user decisions and, in turn, interact with TS under EWCs. Furthermore, the concept of “Disruption Containment Threshold” and the associated “Disruption Mitigation Gap” are proposed to quantify scenario-dependent capacity limits against cross-system disruptions. Finally, simulations show that the rainstorm-induced flooding scenario intensifies these interactions, causing large‑scale traffic congestion and insufficient PSC.