State-of-Charge Balancing Control Strategy Based on Discrete Consensus Algorithm for Battery Energy Storage in Islanded Microgrid

Abstract

This paper proposes state-of-charge (SOC) balancing control based on discrete consensus algorithm to improve the accuracy of power dispatch of the battery energy storage systems (BESS), reducing system cost and prolong the service life of the BESS in islanded microgrid. This has been achieved with hierarchical distributed secondary cooperative control based on discrete consensus algorithm, which modifies the BESS output power to reach a balanced SOC. The control structure has two layers. The cooperative control works as the secondary layer, obtaining equal SOC of the BESS of the grid through interchanges information of energy storage systems state of charge (SOC) with its neighbors. BESS control approach as the primary control layer, they are able to realize the output power sharing and the balancing discharge rate by regulating the virtual resistance. The simulation platform is built based on Matlab/Simulink software. The validity and feasibility of the proposed control strategy has been further verified by various simulation results.