Towards a realistic topological and functional modeling for vulnerability analysis of interdependent railway and power networks
Résumé
Railway systems and power grids are recognized as two of the most important critical infrastructures. The majority of European railway networks are electrified, and power transmission networks represent usually the main power supplier. Railway and power networks share thus a unidirectional interdependency, as the railway network functionality depends on the power network. Due to this interdependency, failures in power networks have the potential of causing vast disruption in the dependent railway networks. Despite this, the issue of modeling interdependent railway and power networks has not been addressed sufficiently carefully in the existing literature. Furthermore, the treatment of cascading failures in power networks and their consequences in railway networks is limited and approximative. In this work, we propose a modeling framework which accounts for more realistic assumptions on the interconnections topology and the cascading failures dynamics. Firstly, we model the interconnections between the railway and external power network by introducing the traction power network, which acts as a bridge between the external power grid and the railway network. Secondly, we model cascading failures in the external and traction power networks with an approach based on the DC power flow model. Thirdly, we suggest a simple approach to estimate the negative consequences on the railway network due to load shedding in the traction power network. Vulnerability analysis is performed to estimate the negative consequences in the railway network due to different failure scenarios in the external power network. Sensitivity analysis on the initial assumptions is also performe