Distributed Power Processing based Cell-level Battery Energy Storage System

This paper proposes a Distributed Power Processing based Battery Energy Storage System (DPP-BESS) for improving the performance and reliability of the battery storage system. One dedicated Dual Active Bridge Converter (DABC) is connected to each cell of the battery pack, and all outputs of DABC are connected in a series-parallel combination as per the requirement for dc-link voltage, and power rating of the DPP-BESS. The main features of the system are: to determine the charging/discharging characteristics of different types of battery cells, to avoid the unnecessary discharging/charging phenomena in the battery within one cycle time, providing isolation between cells and the central inverter, and to improve the optimal power flow to/from each battery cell. Operating principle, design optimization, small signal modeling, and control scheme of the system are presented. The performance of the proposed system is validated through simulations in MATLAB®, SIMULINK®.