Vulnerability Identification and Evaluation of Interdependent Natural Gas-Electricity Systems

The intensified interdependency of natural gas and electricity systems poses urgent needs and new challenges in identifying vulnerable components of the interdependent system, which could be significantly different from those of individual systems because of the interdependency. This paper proposes a method to identify and rank vulnerable components of interdependent natural gas-electricity systems. Specially, a topological model and the vulnerability index for the interdependent system are constructed, and vulnerable component identification method is put forward to select and rank components by simultaneously considering topological and functional vulnerabilities. The proposed vulnerable component identification method is quantitatively assessed via a security evaluation approach, which calculates electricity and gas supply-demand imbalance when the vulnerable components are out of service. Numerical results of a 6-bus electricity/7-node gas system and a modified IEEE 118-bus electricity/20-node gas system illustrate effectiveness of the proposed method.