A transient equivalent circuit model of lithium-ion batteries for the external short circuit fault in BESS

The external short circuit (ESC) fault can cause large current within a short period of time, potentially resulting in serious accidents in battery energy storage stations (BESS). However, the transient behavior of BESS under ESC faults remain insufficiently understood, which hinders the development of precise protection strategies. To accurately estimate transient behavior of BESS during ESC, this work proposes a transient equivalent circuit model of lithium iron phosphate (LFP) batteries. Experimental tests are conducted under various state of charge (SOC), capacities, and external short-circuit resistances to investigate the ESC fault characteristics. A novel equivalent circuit model of LFP battery is then developed to capture the transient electrical behavior of LFP batteries during ESC faults. The performance of the proposed model is validated through experimental tests and data obtained from an actual BESS. The proposed model demonstrates high capability in simulating ESC characteristic and offers insight into fuse configuration and protection design for BESS.