An Improved Distributed Secondary Control Strategy for Battery Storage System in DC Shipboard Microgrid

In this article, an improved distributed secondary control strategy is proposed to achieve state of charge (SoC) balance, accurate load current sharing, and bus voltage recovery for battery storage system in dc shipboard microgrid. First, each battery storage unit (BSU) is regarded as a multiagent, and a neighbor-to-neighbor communication network is constructed to reduce the system communication burden. Each BSU is based on distributed consensus protocol, and global consensus can be achieved only by communication between adjacent BSUs. On this basis, a novel consensus-based SoC balancing algorithm is proposed to achieve accurate load current sharing, and a dc bus voltage controller is designed to achieve secondary regulation of the bus voltage. Furthermore, the SoC convergence characteristics, systems stability analysis, global dynamic model, and steady-state analysis of the proposed control strategy are studied. Finally, the simulation and StarSim HIL experimental results show that the proposed control strategy can achieve SoC dynamic balance, accurate load current sharing, and average bus voltage recovery under various complex conditions, and has a faster SoC convergence speed than advanced methods.