Bi-Level Optimal Allocation Method of Distributed Energy Resources in Medium and Low Voltage Distribution System Considering Source-Load-Storage Coordination

Large-scale distributed energy resource access brings opportunities and challenges to the flexibility of distribution systems. Currently, multiple voltage levels coexist in distribution systems, research on optimal allocation for the flexibility improvement of distribution systems mainly focus on single voltage level systems, and the collaborative optimization potential of flexibility resources across voltage levels is not fully exploded. Therefore, a two-level optimal allocation method of distributed energy resources for the medium and low voltage distribution system considering source-load-storage coordination is proposed in this paper. First, the influence of distributed renewable energy acceptance is analyzed from the perspectives of flexibility, voltage distribution and topology of different voltage levels. Secondly, a two-level optimal allocation model of distributed energy resources in medium and low-voltage distribution system is formed, the multi-objective model is solved by the non-dominated sorting genetic algorithm II. Finally, an improved medium and low voltage distribution system is used for simulation verification. Results show that the proposed method can reduce voltage deviation and network operating loss, and improve the system economy and flexibility.