On the Restoration of Active Distribution Networks Dominated With Inverter-Based Resources: Challenges, Potential Solutions, and a Roadmap

The growing occurrence and severity of natural disasters worldwide have heightened the likelihood of major blackouts for electricity customers, as these events significantly impact transmission and distribution systems. Therefore, equipping the distribution network with restoration capability becomes even more important as it can decrease the duration and intensity of the blackouts. In this regard, the rapid growth of grid-forming inverters (GFMI) along with battery energy storage systems (BESSs) creates new opportunities to enhance the distribution network’s ability to shorten blackout duration and intensity for the electricity customers. However, optimal utilization of this high number of GFMIs in the restoration process, considering grid and communication uncertainties caused by severe weather conditions, is a challenging task. This article examines the major challenges and presents a research roadmap to enable effective restoration of active distribution networks dominated by GFMIs. The complexities associated with various stages of the restoration process, the impact of uncertainties, and the dynamic challenges arising from the low-inertia nature of modern power systems are investigated through several case studies using a realistically modified IEEE 123-bus system.