Research on the Planning Method of Energy Storage Resources Considering the Enhancement of the Carrying Capacity of the Distribution Network

With the ongoing transformation of China’s power system toward a new-type power system, distribution networks are evolving from traditional passive structures to active and flexible configurations capable of accommodating increasing levels of renewable energy. This transition is driven by the rapid development of distributed generation (DG) technologies such as wind and photovoltaic (PV), which impose significant challenges on the operational stability, power quality, and economic efficiency of distribution systems. To address these issues, it is crucial to establish a robust evaluation framework that can effectively assess and enhance the hosting capacity of distribution networks. In this study, a multi-level comprehensive hosting capacity assessment system is proposed, integrating power quality, economic performance, and supply capability as key evaluation dimensions. Based on the assessment outcomes, a bi-level optimization model is developed for the strategic planning of energy storage resources. The upper-level model is designed to minimize the total annual cost while maximizing renewable energy access and utilization, determining the optimal siting and sizing of wind, PV, and storage units. The lower-level model focuses on minimizing annual network loss and maximizing renewable energy consumption by optimizing real-time operational strategies. To validate the proposed methodology, simulations are conducted on an improved IEEE 33-bus distribution system. Results show that the approach not only significantly improves the hosting capacity of the distribution network, but also enhances its operational flexibility, reduces energy loss, and promotes the efficient integration of renewable energy. The proposed framework provides valuable guidance for planning active distribution networks and deploying energy storage systems under high renewable penetration scenarios.