Magnetic bearing system including a control system for a flywheel and

Abstract

A bearing system for positioning and supporting a rotor having a vertical shaft coincident with a main rotation axis included in a flywheel used for energy storage and high surge power in vehicular applications includes first and second radial force generators disposed in a first plane perpendicular to the rotation axis of the rotor, the first and second force generators including only electromagnets, third and fourth radial force generators disposed in a second plane perpendicular to the rotation axis of the rotor, the third and fourth force generators including only electromagnets, and upper and lower axial force generators each containing an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the force generators includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a desired bearing stiffness. The bearing system also includes upper and lower touchdown ball bearings which are engaged only when the first through fourth radial force generators are unable to maintain the rotor in a predetermined cylindrical volume within the flywheel. A method for controlling the bearing system is also described.