A compact and efficient flywheel energy storage system with integrated magnetic bearings

There is demand for high-speed but light-weight flywheel system for energy and momentum storage. The applications range from replacements for batteries, uninterruptible power supplies and even in space satellites. This paper proposes a new design of a mechanically contactless flywheel system which should be both compact and energy efficient. The flywheel acts as the rotor of the drive system and is sandwiched between two disk-type stators. A combination of active and passive magnet bearings allows the rotor-flywheel to spin and remains in magnetic levitation. The design principles, mathematical model, control theory and simulation results are presented in this paper.