Application of a compact electrochemical energy storage to pulsed power systems

The Pulsed Power Physics Branch at the U.S. Naval Research Laboratory (NRL) is developing a battery-powered, rep-rate charger for a 60 kJ capacitor bank. The goal is to charge a 4800 μF capacitor to 5 kV in four seconds for a fifty shot burst. A bank of LiFePO₄ batteries is used with a full H-bridge converter, a transformer, and a rectifier to transform ≈ 650 V battery voltage to a 5 kV secondary voltage. The LLC topology has been selected for the DC-DC converter, as it offers some advantages in minimizing converter weight and volume. Additionally, the LLC design enables resonant operation to switch at 50 kHz. The work to date has been focused on the design and construction of stable battery modules, and the converter design has been limited to basic circuit simulations and paper studies. Thermal management of the battery modules during operation is essential, as high temperatures will damage the cells. This work will discuss the design and testing of various cooling schemes, with results from experiments.