Coordinated Capacity and Siting of ESSs in Multi-Level Microgrid Clusters

With the large-scale integration of distributed PV, wind power, small hydropower, ESSs, and flexible loads, microgrid clusters exhibit stronger coupling across multiple voltage levels and more complex dynamic interactions. Existing ESS allocation methods mainly focus on economy or total capacity, but insufficiently distinguish the stability support functions of ESSs at the station, feeder, and distribution transformer area levels. To address this issue, this paper proposes a coordinated capacity and siting allocation method for ESSs in multi-voltage level microgrid clusters. The proposed method quantifies the effects of transformers, feeder switches, and power electronic interfaces on disturbance propagation, optimizes station-level and feeder-level ESS capacities, and determines distribution transformer area-level ESS siting according to voltage sensitivity, recovery capability, and stability margin. Simulation results under PV fluctuation, load disturbance, external grid disturbance, and local islanding verify that the proposed method improves voltage recovery, power support, and operational stability while supporting renewable energy utilization, storage resource efficiency, and resilient clean power supply.