Four-level framework for enhancing active distribution network resilience to wind storms

Traditional distribution system planning often overlooks resilience enhancement measures despite the increasing frequency and severity of extreme weather events. This paper presents a four-level resilience enhancement framework to address these challenges, focusing on replacing aging distribution lines, a major contributor to prolonged outages. The framework utilizes fragility curves to assess the impact of wind speed on poles, conductors, and wind turbines, with failure states evaluated through Monte Carlo Simulation (MCS). It introduces a resilience enhancement criterion incorporating repair costs, Distributed Generators (DGs) generation costs, and end-user interruption costs, estimated via a time-based penalty mechanism tailored for extreme weather events. The study also explores the role of local DGs in supporting critical loads through islanding after extreme events. The line hardening planning problem is formulated as a knapsack optimization problem and solved using Particle Swarm Optimization (PSO). The case study demonstrates that hardening lines connecting the distribution system to the upstream grid offers the greatest resilience benefits. Simulation results show that a coordinated line hardening strategy, combined with effective DG operation, can enhance system resilience by up to 80 %, underscoring the importance of integrating resilience planning into distribution system operation for better weather event preparedness and recovery.