Metrics and quantification of power-line and pipeline resiliency in integrated gas and power systems

Due to the increasing interactions between the natural gas system (NGS) and electric power system (EPS), the failures of power-lines or gas pipelines in one system may influence another system and consequently trigger widespread disruptions. Hence, identifying these critical components and protecting them from malfunctions are essential to prevent the collapse of integrated gas and power systems (IGPSs). Considering the effects of both network topologies and operational features on the resiliency evaluation, a novel assessment framework is proposed in this paper to screen out critical power-lines and gas pipelines. First, the framework of IGPSs is introduced and an optimal energy flow (OEF) model is constructed to quickly obtain the operation states under various disturbances. Furthermore, the resiliency metrics (RMs) are developed from structural and operational perspectives respectively. Specifically, structural RMs consider the coupling topologies to capture the structure-related resiliency, while operational RMs analyse the resiliency related to gas and power flow to capture physical operation characteristics. Finally, an assessment algorithm synthesizing all the metrics is proposed to quantify the comprehensive resiliency, based on which critical power-lines and pipelines (CPPs) can be detected. The effectiveness of the proposed approach is validated by an IGPS test system.