Strategic investments for enhancing power system resilience through zonal microgrids

The existing power distribution system is confronted with a myriad of challenges and encompassing issues such as aging infrastructure, dynamic shifts in energy demand patterns and disturbances induced by climate change. Given the pivotal role played by the power sector in contemporary society by providing essential services and supporting economic activities, ensuring the resilience of power distribution systems is a top priority for governments, utilities and other stakeholders like consumers. The extant power grid characterized by its aging components, requires a complete overhaul to enhance its resilience in the wake of increasing weather-induced power disruptions attributed to climate change. However, outright replacement of the existing grid is presently deemed economically impractical, entailing significant costs and negative social impacts. Instead, a more pragmatic strategy to augment the overall system resilience involves identifying and reinforcing critical sectors of the grid at a reasonable cost and with reasonable disruptions. This paper presents a novel resilience enhancement framework for power distribution systems based on N-1 Impact Analysis. Unlike traditional reliability studies, the proposed method prioritizes critical lines based on the unserved energy impact of their outages and partitions the network into resilience-driven zones. An Improved Grey Wolf Optimizer (IGWO) is used to size and allocate DERs within these zones, considering operational constraints and investment costs. The approach is validated on a real utility feeder modeled in OpenDSS and MATLAB, achieving significant reductions in unserved energy and demonstrating superior cost-effectiveness compared to existing approaches. The framework provides utilities with a practical, data-driven tool for targeted resilience planning.