This work demonstrates a method of integrating and operating hybrid battery energy storage systems (BESSs) for grid applications. The developed method provides flexibility, modularity, safety and economic benefits to utility-scale storage integration. Here, a hardware testbed and a control software have been designed, where the former comprises commercial Lithium-iron-phosphate (LiFePO4) and Lead Acid (Pb-acid) cells, custom built Dual Active Bridge (DAB) DC-DC converters, and a commercial DC-AC conversion system. The control software implements hybrid charge/discharge protocols that are suitable for each battery technology for preventing degradation, and perform uninterrupted quality checks on selective battery packs.
