High Energy Density Power Sources for Unmanned Surface Vehicle (USV) Sensor Payloads

Unmanned Surface Vehicles (USVs) require a low signature power source for on-station operation of sensor payloads. The power source must have a high energy density, be reliable, require low maintenance, and be able to withstand salt spray and heavy seas for a two week mission duration. In addition, the payload duty cycle requires up to 25kW peak loads for ten seconds out of every minute, with constant loads of several kilowatts. For the proposed Phase I effort AeroVironment will investigate the feasibility of using the propulsion diesel engines in hybrid with a lithium battery pack and potentially other power sources. Strategically sizing the battery pack to handle the ten second peak loads and average continuous loads while on station allows the propulsion diesel engines to operate intermittently as an energy storage system charger. Under critical conditions, the battery pack or other power source would be the sole supply of sensor payload power, thus allowing USV silent operation. AeroVironment will overcome project technical challenges using our experience gained developing many hybrid electric vehicle systems. By demonstrating feasibility, we will assist the Navy to develop silent mode, low signature operation of its USV fleet for periods of two weeks.