Overview of Technical Specifications for Grid-Connected Microgrid Battery Energy Storage Systems

Increasing distributed topology design implementations, uncertainties due to solar photovoltaic systems generation intermittencies, and decreasing battery costs, have shifted the direction towards integration of battery energy storage systems (BESSs) with photovoltaic systems to form renewable microgrids (MGs). Specific benefits include, but are not limited to, seamless switching and islanding operations during outages and ancillary grid services. The evolution of battery chemistries and other components has also further enhanced practicality; however, developing these multifaceted MGs involves complexity in the design process. Consequently, stakeholders rely on connection standards and operational requirements to guarantee reliable and safe grid-connected operations. This paper presents a technical overview of battery system architecture variations, benchmark requirements, integration challenges, guidelines for BESS design and interconnection, grid codes and standards, power conversion topologies, and operational grid services. In addition, a comprehensive review of the control strategies for battery equalization, energy management systems, communication, control of multiple BESSs, as well as a discussion on protection blinding and intentional islanding using BESSs is also provided. Finally, a discussion of the islanded and black start operation results for time-based analysis and standard validation of a 3MW/9MWh BESS in a grid-connected MG at the Florida International University (FIU) Engineering Campus is presented.