Coordinated Optimization Strategy for Hybrid Energy Storage toward High-PV-Penetration Distribution Networks

Addressing voltage violations and renewable energy absorption bottlenecks arising from high-penetration photovoltaic (PV) integration, this paper proposes a hierarchical optimisation architecture for a Hybrid Energy Storage System (HESS) based on microgrid-distribution network coordination to enhance collaborative regulation of energy storage across multiple microgrids. The methodology comprises a PV hosting capacity assessment model and an HESS operation model that accounts for power supply reliability, forming a two-layer planning framework that integrates distributed decision-making with centralized coordination. At the microgrid level, HESS capacity is determined to minimise the local comprehensive cost, while the allocation ratio between lithium-based and hydrogen-based energy storage is optimised to maximise renewable energy utilization. At the distribution network level, a global collaborative dispatch of multi-microgrid energy storage is performed to minimise total system cost and voltage deviation, thereby achieving cross-regional power balance and voltage support. Simulation verification is conducted using actual distribution network data from Zhejiang Province and a 33-node test system. The results indicate that the proposed coordinated operation strategy can effectively improve voltage quality, enhance the PV absorption rate, and increase economic benefits.