Advanced Flywheel Energy Storage for Pulsed Power Applications

During the NAVY STTR Phase II Calnetix will further develop its concept of advanced flywheel system proposed in Phase I and will demonstrate the validity of the underlying principles through building and testing a system prototype. This prototype will be a fully functional system capable of supporting up to 2MW of pulse power with the ability of producing 500kW (30 seconds) loads in high-duty-cycle operation. The need for this system has been identified in both NAVY and commercial applications. The proposed design will feature several novel technical solutions resulting in a very compact and reliable high-performance system. These include unique magnetic suspension based around patented Calnetix homopolar PM-biased magnetic bearings, further improved to increase system efficiency and meet high dynamic load requirements encountered in NAVY applications; power electronic vector controls, which allows for boosting power output of PM machines by several times for short periods of time; as well as several technical solutions addressing thermal issues of operating a PM motor/generator in both high-duty-cycle and pulse-power flywheel applications. All of these innovations are rather fundamental in nature, and once proven, could be transferred to other flywheel systems varying in powers and amounts of stored energy. In particular, a concept of a flywheel system to provide sufficient energy and power to launch and aircraft in EMALS has been proposed during the Phase I study.