Balanced discharging of power bank with buck-boost battery power modules

The operation of a battery power bank with the buck-boost type battery power modules (BPMs) is studied. All BPMs in the power bank are collaboratively to cope with the load requirements but substantially are operated individually. They can be scheduled to discharge currents from batteries in accordance with their state-of-charges (SOCs) and the operating modes of the converters. The operations of BPMs are analyzed to derive the current distribution equations and then to figure out the discharging strategy accordingly. Experimental results demonstrate that excellent performance on charge equalization can be achieved during the discharging processes. In addition, a fault-tolerance function can be included to isolate those with completely exhausted or damaged batteries. These features are helpful to maintenance and management of a battery power system.