Nodal Reliability Evaluation of Interdependent Gas and Power Systems Considering Cascading Effects

The ever-increasing utilization of natural gas has strengthened the interdependence between power system and natural gas system (NGS). Due to the bidirectional interactions between the two systems, the disturbances in one system may spread tothe other one, triggering a disruptive avalanche of subsequent failures. When considering the cascading effects, the failure of a very small fraction of components can lead to catastrophic outages in the interdependent gas and power systems (IGPSs). This paper proposes an approach for the reliability evaluation of IGPSs considering the interdependence-induced cascading effects. Firstly, a dynamic cascaded analysis model is developed to describe the temporal and spatial process of cascading effects considering different dynamic behaviors between power system and NGS. By taking the gas velocity and line pack into consideration, the re-dispatch model of NGS is set up to characterize the dynamic variation of gas pressures and flow rates between two time periods. Then, the framework for the reliability evaluation of IGPSs considering cascading effects is proposed by combining the dynamic cascaded analysis model and Monte Carlo simulation (MCS) techniques. Furthermore, nodal reliability indices for both NGS and power system are proposed to quantify the impacts of cascading effects on the reliabilities of IGPSs. The proposed methods are validated using an integrated gas and power testing system.