Optimal Smart Switch Deployment With Tri-Layer Synergized Resilience Enhancement Considering Multiple Heterogeneous Faults

Smart switches such as remote-controlled switches (RCSs) and soft open points (SOPs) provide powerful fault isolation and reconfiguration ability for flexible distribution networks (FDNs) to enhance resilience. However, resilience-oriented optimal deployment of smart switches in FDNs encounters two major challenges: (1) Multiple heterogeneous faults can hardly be incorporated. (2) Lack of explicit modeling for the topological coupling relationship between pre-disaster operation strategies and post-disaster multi-phase fault management procedures. To address these challenges, an optimal smart switch deployment method is proposed by constructing a tri-layer synergized resilience enhancement model. This model addresses multiple heterogeneous faults, including line failures, substation transformer issues, and switch malfunctions. And the topological coupling relationship between RCSs and SOPs deployment, pre-disaster proactive islanding, post-disaster fault propagation, fault isolation, and service restoration is meticulously constructed. Subsequently, based on resilience metrics and fault topology metrics, a two-stage K-medoids clustering method is proposed to select critical scenarios, which balances computational feasibility and precision. Then, the proposed model is transformed into a scenario-based two-stage distributionally robust optimization formulation. Finally, case studies on 40-node and 126-node urban distribution networks validate the approach, highlighting the impact of heterogeneous faults and the effectiveness of proactive islanding and SOPs in enhancing FDN resilience.