Consensus-based multi-converter power allocation strategy in battery energy storage system

Abstract

Battery energy storage system (BESS) commonly consists of multiple power conversion systems (PCSs) under parallel operation, which are controlled by a centralized controller to realize power allocation. As the number of PCSs increases, the topology and communication structure of the BESS become more complex, reducing the ability of centralized controller to respond quickly and flexibly. An effective approach to address this problem is to develop a distributed power allocation strategy. Consensus theory, as an advanced distributed algorithm, is based on partial information interaction to achieve the state consistency of multiple agents. This paper presents a consensus-based strategy to realize efficient power allocation under distributed framework. The system convergence is analyzed under communication failure to demonstrate the robustness of the consensus-based control strategy. Considering state-of-charge (SOC) equalization, operation efficiency and battery life loss, the consensus factor of the consensus-based power allocation model is switched according to specific battery states and application scenarios. Finally, the effectiveness of the proposed strategy is validated by simulation and real-world experiment in peak shaving and mitigating wind farm fluctuation scenarios.