Cooperative Control of Distributed Energy Storage Systems in a Microgrid

TLDR

Energy storage systems support microgrid frequency control, but their charging‑discharging efficiency depends on rate and state‑of‑charge, requiring coordinated operation to balance supply and demand amid renewable intermittency. The study proposes a distributed cooperative control strategy to coordinate ESSs for supply‑demand balance while minimizing charging‑discharging power loss. The method coordinates ESSs in a distributed manner, optimizing their charging and discharging schedules to reduce power loss. Simulation results validate the effectiveness of the proposed approach.

Abstract

Energy storage systems (ESSs) are often proposed to support the frequency control in microgrid systems. Due to the intermittency of the renewable generation and constantly changing load demand, the charging/discharging of various ESSs in an autonomous microgrid needs to be properly coordinated to ensure the supply-demand balance. Recent research has discovered that the charging/discharging efficiency of ESSs has remarkable dependence on the charging/discharging rate and state-of-charge of the ESS. This paper proposes a distributed cooperative control strategy for coordinating the ESSs to maintain the supply-demand balance and minimize the total power loss associated with charging/discharging inefficiency. The effectiveness of the proposed approach is validated by simulation results.