Distributed Stochastic Optimal Dispatching Strategy for the Energy Storage-Integrated Soft Open Points in Distribution Networks

In this study, we propose a distributed energy management strategy for multi-terminal energy storage integrated soft open points (ES-SOPs) to enable the flexible and coordinated operation of interconnected distribution networks (DNs) with high renewable penetration. We designed a bi-level distributed optimization framework to decompose the overall coordination problem into local DN operations and global ES-SOP management. The operational cost of each DN is minimized under relaxed reliability constraints using a distributionally robust chance-constrained (DRCC) formulation. The coordination layer minimizes the converter and battery losses and ensures a power balance between the battery and soft open points (SOPs). The DRCC approach addresses the PV and load forecast uncertainties without assuming specific distributions. The optimization problem is implemented using an analytical target cascading approach that ensures scalable convergence and preserves the DN independence. We conducted case studies to validate the effectiveness of the proposed method in balancing the operational cost of the DNs and power grid reliability by varying the key parameters in the DRCC framework (i.e., ambiguity set radius and risk parameters).