Vulnerability assessment of interdependent road-power networks with probability-based coupling strategies

The road network and power grid are vital components of urban infrastructures, but their interdependence significantly amplifies vulnerability. Thus, this paper studies the vulnerability of the interdependent road-power network constructed by a probability-based coupling strategies. First, the road network and the power grid are abstracted as two single networks, respectively, where user equilibrium and the Kirchhoff’s law are used to construct the cascading failure model. Then, to establish an effective interdependent relationship between them, we propose ranking proportion reflecting the ranking of a node in the single network and construct the interdependent link between networks through the probability determined by the difference of ranking proportion, thereby developing a probability-based framework for generating coupling strategies. This can produce coupling strategies with a specific assortativity coefficient based on various kinds of metrics. Finally, we use the real-world Shanghai road network and the IEEE 118-node power grid to conduct a case study on the vulnerability of the interdependent network with sixteen assortative and disassortative coupling strategies obtained by the proposed framework with four topological and functional metrics. Experimental results show that under intentional attacks, the interdependent network with disassortative coupling strategies regarding fluctuations of power loads exhibits slight vulnerability; under random failures, disassortative coupling strategies regarding the power load mitigate its vulnerability. In addition, there is little difference in the vulnerability of the interdependent network with assortative coupling strategies regardless of attack strategies. Besides, its vulnerability is more significant while adopting coupling strategies regarding classic topological metrics.