SmartBattery: An Active-Battery Solution for Energy Storage System

The use of battery energy storage systems has gained wider attention in many sectors such as: power system, automotive, aircraft, oil and gas, among many others during the recent years. However, the association of batteries in a bank without the proper control may lead to problems to the batteries such as voltage imbalance, uneven degradation and incompletely use of the whole potential of the battery bank. This paper introduces a new concept of battery charger topology, named herein as SmartBattery, which is composed of a two-stage dc/dc converter integrated upon each battery pack. This solution allows each battery unit to be charged/discharged with different current profiles, even when they are series-connected. Then, this paper proposes a coordinated control strategy to balance the battery units in different stages of degradation and/or states of charge, without the need of bypassing any storage unit. Simulation results are performed to verify the equalization among batteries in a bank with different ages or states of charge during charging and discharging processes.