Supply resilience assessment of natural gas pipeline network systems

Resilience is one of the important components of system safety evaluation and optimization, the research of which for natural gas pipeline network system (NGPNS) is still in initial stage, especially for the resilience indexes and process description. To evaluate the resilience of NGPNS more synthetically and practically, considering different types of disturbances, an integrated framework is proposed for evaluating the supply resilience of NGPNS, involving the topology and operating conditions. The characteristics of both deterministic and probabilistic disturbances are analyzed. The innovations and corresponding methodology are that global resilience, temporal resilience and threshold resilience are proposed as the resilience evaluation indicators; the maximum flow method and shortest path method are integrated with operation and structural parameters to calculate the amounts and routes of gas supply, before and after disturbance; based on complex networks theory and graph theory, the traditional view point is changed from whole system to the affected area. The results can contribute to the guidance of NGPNS topological designing and the building of prewarning scheme, including spare gas sources and gas routes optimization, and the strategy of pipeline maintenance, also can help the rapid analysis of disturbance consequences and the enhancement of evaluating accuracy in NGPS resilience.