Centralized control of large capacity parallel connected power conditioning system for battery energy storage system in microgrid

This paper presents a centralized control scheme that coordinates parallel operations of large capacity power conditioning system (PCS) for battery energy storage system (BESS) in Micro-grid (MG). The theoretical analysis of the different operation modes are studied, including grid-connected mode, islanded mode and transfer mode. To improve the power sharing accuracy during the islanded operation, a parallel control strategy based on communication network is applied in large-capacity system. Moreover, a novel seamless transfer method is proposed to implement three-phase PCS transition between grid-connected mode and islanded mode. Simulation and experimental results are provided to validate the feasibility of the proposed control strategy.