Flywheel Energy Storage System and Their Applications

The use of flywheels to store energy is a technology centuries old. The confluence of several modern technologies has resulted in flywheels becoming a viable solution for the needs of the transportation, electric utility, and aerospace industries. Advancements in power electronics and high performance composite materials plus the development of reliable magnetic bearings have enhanced the energy storage density and the power delivery capability of flywheel systems, enabling them to serve many new applications. This paper discusses several flywheel energy storage applications and explores in some detail the flywheel systems for the Federal Railroad Administration program, >Advanced Locomotive Propulsion System> (ALPS), and a flywheel system providing energy storage for a hybrid electric bus. The unique motor designs required for these systems are also discussed.