Reliability assessment for modern distribution networks with grid-forming energy storage

With the increasing penetration of battery energy storage system (GFM-BESS) with grid-forming control in distribution network, power load could be continuously supplied during fault with its significantly dynamic support capacity, thereby preventing the tripping of distributed renewable sources (DRSs). The available power from the DRSs and GFM-BESSs will restore more affected power load, effectively enhancing reliability level of distribution network. In this paper, a novel reliability assessment framework is developed by integrating transient simulation with post-fault system recovery, and the fault consequence is analyzed by minimizing load shedding with a mixed-integer programming model. Case studies of an IEEE 33-bus system demonstrate that the ability of GFM-BESS in transient voltage and active power support can significantly enhance the reliability of distribution networks.