A Resilience Enhancement Method for Distribution Networks Under Extreme-Event Scenarios Considering Flexible Interconnection via Energy Routers

An energy router (ER), featuring flexible multi-port access, bidirectional power regulation, and cross-regional energy exchange, provides versatile control capabilities for fault isolation, critical-load supply, and post-disaster restoration in distribution networks under extreme-event scenarios. However, existing studies have not fully exploited the dynamic relocation and flexible power-transfer capabilities of ER ports when post-disaster network fragmentation and multiple islands coexist; moreover, existing distribution-network resilience optimization methods depend on assumptions about the extent of extreme-event damage. To address these issues, this paper proposes a coordinated pre-event defense and post-event restoration method for enhancing distribution network resilience under extreme-event scenarios while accounting for ER flexible interconnection capabilities. First, a virtual node-based equivalent model of a multi-port ER-integrated distribution network is established; it preserves radial operation while representing ER port capacities and internal power balance. Second, an information-gap decision theory (IGDT)-inspired scenario formulation is introduced in the pre-event defense stage, where cumulative damaged-line resistance serves as a simplified damage-severity proxy for the test system; a coordinated line hardening and ER defense model is then developed, and the defense resource allocation under a given annualized pre-event investment limit (the defense budget) is determined through siting enumeration and a sequential search over the conservativeness coefficient β. For the post-event restoration stage, a multi-period model coordinating sequential line repair and dynamic ER port relocation is formulated, and a superset topology transforms time-varying network reconfiguration into the sequential switching of virtual-branch connection states in a static expanded network. Case-study results demonstrate that the proposed method improves the ability of a distribution network to withstand extreme-event scenarios under a limited budget, reduces the total weighted energy not supplied over the restoration horizon, and improves both critical-load restoration efficiency and distributed generation utilization. Relative to fixed ER ports, dynamic relocation primarily improves critical-load prioritization rather than the total energy supplied. The proposed coordinated pre-event defense and post-event restoration framework provides a theoretical basis for resilience planning and the post-disaster dynamic restoration of ER-integrated distribution networks.