Arc-flash in large battery energy storage systems - Hazard calculation and mitigation

This paper deals with the arc-flash haz ard calculation in battery energy storage systems (BESSs). The lack of international harmonized standards, coupled with a foreseeable increasing use of BESSs, makes this subject very interesting, especially due to the practical involvements related to arc-flash hazard associated with BESS maintenance operation. A Li-ion battery circuit model, based on experimental short-circuit tests conducted by TERNA (the Italian transmission system operator) and a non-linear arc resistance model are used to assess the incident energy related to arc-flash. Efficient and cost-effective solutions, able to reduce incident energy below the safe value 8 cal/cm 2 and based on the installation of fast-acting fuses, are then proposed and discussed.