Small signal analysis and dynamic modeling of a battery energy storage system in a DC microgrid

Abstract

This paper presents a comprehensive small signal analysis of two types of battery energy storage systems (BESSs), including a voltage-controlled BESS (V-BESS) and a current-controlled BESS (C-BESS). This study also introduces dynamic models for integrating these two BESS configurations within a DC microgrid context. Through small signal analysis and participation factor analysis, this study investigates the interplay between the BESS and the DC microgrid and the internal interactions within the BESS. Subsequently, pivotal modeling parameters are discerned, and their impacts on system dynamics due to variations are unveiled through a sensitivity analysis. These results were verified through real-time software-in-the-loop simulations using an OPAL-RT 5707XH. Furthermore, this paper proposes dynamic models for both V-BESS and C-BESS integrated with a DC microgrid that can capture the dominant behavior of BESSs in a DC microgrid with relatively low computation demands. Potential applications of this study not only include providing a reference for modeling BESSs in a DC microgrid but also providing a guideline during the design and operation stages of a BESS in a DC microgrid. Finally, due to their modularity and scalability, the proposed dynamic models can be easily applied to the design and testing of BESS controllers.