Distributed Coordinated Control Strategy for Grid-Forming-Type Hybrid Energy Storage Systems

Existing hybrid energy storage control methods typically allocate power between different energy storage types by controlling DC/DC converters on the DC bus. Due to its dependence on the DC bus, this method is typically limited to centralized energy storage and is challenging to apply in enhancing the operation of distributed energy storage. To address this issue, this paper proposes a distributed hybrid energy storage control strategy based on grid-forming converters. By flexibly utilizing Virtual Synchronous Generator (VSG) control and virtual impedance control, the power distribution capability of the grid-forming converter is enhanced to meet the needs of hybrid energy storage. At the same time, a strategy based on multi-agent theory is employed to enable multiple distributed energy storage sources to collaboratively achieve hybrid energy storage. This strategy can be directly applied to energy storage systems connected to the AC grid, facilitating more efficient utilization of renewable energy. It also enhances the reliability of distributed energy storage systems, contributing to sustainable development goals. Furthermore, leveraging multi-agent theory, it offers advantages such as low communication overhead and high flexibility. Hardware-in-the-loop (HIL) simulation experiments have validated the effectiveness of this strategy.