Advanced Flywheel Energy Storage for Pulsed Power Applications

Existing battery based energy storage systems are not suited for short duration, high cycle life, deep discharge, and small required size applications. Ultra/super capacitors (UC) are limited by some of the same issues as batteries, i.e. cycle life limitations, disposal, and continue to remain at a much higher cost than batteries. Flywheels can cost effectively fill the short duration, high cycle life applications that batteries and UC's cannot, specifically as products that are cost competitive with existing battery based systems for specific applications where flywheels out perform and offer benefits. Adequate energy is present in conventional flywheel storage systems to provide more power for a shorter duration. A flywheel designed for 125kw for 16 seconds stores enough energy to provide 2MW for 1 second. To provide high discharge for very short durations, the generator and power electronics must be configured such that the power from the stored energy can be realized. Higher speed flywheels allow the generator to be much smaller, minimizing its size and cost. This Phase I will focus on developing a conceptual design for a pulsed power flywheel system. The focus of this effort will be on the motor/generator design and the power electronics design.