T08.5 - Enhancement of Hybrid Energy Storage Dynamics Assisted by Battery Current Management

One way to increase the power rating of an energy storage system is to combine different sources or strings of cells, where one is optimized for power delivery, and the other for high-energy capacity. These strings are typically connected in parallel, and current distribution strongly depends on system parameters. As a result, the battery string may be exposed to currents that exceed its maximum rating. To prevent irreversible battery damage, the common practice is to disconnect it from the bus, which significantly reduces the power available to the load. This study explores an architecture where battery current is actively managed during high-current transient events, ensuring protection from overcurrent while maintaining power contribution to the load. A transportation-oriented case study demonstrates that this architecture can double the maximum power of a hybrid energy storage system at a cost of about 30% reduction in total energy content. A proof-of-concept 24 V hybrid energy storage prototype. incorporating a battery current limiter was built and tested in the laboratory. The limiter, rated at 750 W, enables the system to deliver 1.5 kW without exceeding the battery rating.