Resilience enhancement method for IEGS considering line pack and collaborative recovery of different sub-systems

The increasing interdependency between power distribution systems (PDS) and natural gas systems (NGS) imposes great challenges to the reliable and secure operation of integrated electricity-gas systems (IEGS) under extreme weather events. To minimize its impact, a multi-stage resilience enhancement method is proposed in this paper. The multi-stage defense and response process of IEGS under extreme disasters is modeled in detail, which is divided into four sequential stages, including the prevention stage (PRE), the degradation stage (DEG), the isolation stage (ISO), and the recovery stage (REC). Wherein, the two-way coupling relationship between PDS and NGS is established to reflect the process of two-way cascading failure propagation, and the line pack is leveraged in the multi-stage process to boost the resilience of IEGS against EWEs. The overall method is formulated as a mixed integer second-order cone programming (MISOCP) model, and the progressive hedging algorithm is used to reduce the computational burden caused by multiple scenarios. An IEGS, consisting of a 33-bus PDS and a 20-node NGS, is used to validate the proposed method, and the results reveal that the proposed method can significantly improve the resilience of IEGS.