Pulsed-Current Operation of Smart Batteries Through Warm Redundancy

Batteries are increasingly present in residential, commercial, and industrial applications. The battery energy storage systems (BESS) are based on the series/parallel association of batteries with the same technology and similar operating time. The current technology that employs constant dc current during the charging process is not compatible with second-life batteries, since they may have different capacities. Moreover, conventional BESS are not fault-tolerant. Therefore, this work investigates a more flexible and reliable BESS architecture, integrating a half-bridge converter to the batteries, together with a simple control algorithm based on pulsed-current charge/discharge. This work implements a warm redundancy where there is always one battery bypassed, which can extend the battery lifetime and improve BESS fault tolerance. The results of this work are based on PLECS simulations of a bank of eleven batteries using the algorithm and experiments with three smart batteries.