Proactive Microgrid Formation Strategy for Resilience Enhancement of Distribution Systems in Extreme Conditions

Microgrid formation (MF) is a promising solution to enhance the resilience of distribution systems in extreme conditions. The traditional MF methods follow the post-outage recovery criteria, which divide the on-outage areas into multiple microgrids after the faults occur. However, such passive methods spend much time restoring the large-scale outage area, reducing the abilities of distribution systems in resisting and rapidly recovering from an extreme event. To further enhance the resilience of distribution systems in extreme conditions, this paper proposes a proactive MF method to sectionalize the distribution system into several microgrids (MGs) prior to the extreme events and ensure the power supply to critical loads when the faults occur. Specifically, an ambiguity set is constructed to describe the line failure probability distribution. And a distributionally robust optimization (DRO) model is proposed to minimize the expected amount of load shedding with regard to the worst-case distribution within the ambiguity set. Moreover, the proposed DRO model is recast to facilitate the solution with column-and-constraint generation (C&CG) algorithm. By proactively partitioning the system into multiple MGs, the resilience of the distribution system in extreme conditions is enhanced. The effectiveness of proposed method is validated by numerical simulations with the modified IEEE 37 bus system.