Research on Grid-Forming Energy Storage Configuration for Distributed Photovoltaic Consumption and Reliability Improvement of Distribution Network

[Objective] High-penetration distributed photovoltaic（PV）grid integration leads to insufficient power absorption capacity in distribution networks. Meanwhile，the development of new distribution systems imposes higher reliability requirements. Grid-forming energy storage，with its flexible power synchronization control capabilities，possesses the ability to both promote distributed PV consumption and enhance reliability in new distribution networks. This paper proposes an optimal configuration model for grid-forming energy storage that considers both distributed PV consumption and reliability improvement in distribution networks. [Methods] First，a bi-level optimization model for the siting and sizing of grid-forming energy storage is established. The upper-level model considers fault conditions and load importance to establish an energy storage siting model for improving distribution network reliability. The lower-level model considers the uncertainty of distributed PV systems to establish an energy storage sizing model for enhancing PV consumption. Specifically，the confidence set for the probability distribution of PV uncertainty is constrained by 1-norm and ∞-norm constraints，and is solved using the column and constraint ceneration（CCG）algorithm based on the distributionally robust optimization. Second，a comprehensive evaluation index system incorporating reliability，distributed PV consumption，and economic performance is established. The optimal configuration scheme is obtained using an improved Technique for Order Preference by Similarity to Ideal Solution（TOPSIS）method. [Conclusions] The proposed algorithm is validated through a modified 33-node test system. The results show that compared with traditional energy storage schemes，the proposed model improves the reliability index by more than 10%，and reduces the distributed PV curtailment rate by 7.44%. The optimal effect is achieved by configuring grid-forming energy storage at four key nodes. [Conclusions] The proposed grid-forming energy storage optimization configuration method significantly improves the distributed photovoltaic capacity and reliability of distribution network，providing reference for planning and investment in distribution networks with high-penetration distributed PV integration.