Influence Graph-Based Method for Sustainable Energy Systems

To reduce carbon emissions from fossil fuel generators in sustainable energy systems, an option is increasing the integration of gas-fired generators into the power system. The increasing reliance on natural gas for electricity generation has strengthened the interdependence between the electric power network and the natural gas infrastructure within the Integrated Power and Gas System (IPGS). This strengthened interdependence increases the risk that disruptions originating in one system may propagate to the other, potentially leading to extensive cascading failures throughout the IPGS. Ensuring the reliability of critical energy infrastructure is vital for sustainable development. This paper proposes a vulnerability assessment method for the IPGS using an influence graph, which can be formulated based on fault chain theory to capture the interactions among failed components in the IPGS. With the influence graph, eigenvector centrality is used to pinpoint the critical components in the IPGS. The proposed methodology is validated using 39-bus 29-node IPGS through the Scenario Analysis Interface for Energy Systems (SAInt) software version 3.5.17.7. Results show that the proposed method has effectively identified the most critical branches in the IPGS, which play a key role in initiating cascading failures. These insights contribute to enhancing the resilience and sustainability of interconnected energy systems.