Uninterruptible power supply using a high speed cylinder flywheel

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder with length greater than diameter and hardness of the steel in the flywheel at the centerline throughout the axial length of the large diameter portion is hardened to a hardness greater than 229 Brinnell.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on a passive radial with active axial magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said passive radial magnetic bearings located on the upper and lower ends of the flywheel generate passive axial forces that are in opposite directions.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said passive radial magnetic bearings are comprised of rotating bearing portions located on the axial faces of the flywheel that cooperate with upper and lower stationary bearing portions.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy and a discharge cycle counter system is used to limit the number of discharges the flywheel can experience.

A process for manufacture of a steel cylinder flywheel for a flywheel uninterruptible power supply wherein the steel is hardened in the form of a multiple flywheel log prior to being cut and machined into individual flywheels.

A process for manufacture of a steel cylinder flywheel for a flywheel uninterruptible power supply wherein the flywheel is ultrasonically scanned for flaws after quenching and tempering.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder with length greater than diameter and during normal operation stores more than 4 watt-hours per pound of flywheel weight.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system, said flywheel has an attached motor/generator for accelerating and decelerating said flywheel for storage and retrieval of energy wherein the uninterruptible power supply is used to provide back up power lasting more than one hour for telecommunications applications.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder that spins at a speed in normal operation that would cause a fracture failure in less than one hundred thousand cycles between normal operating speed and ten percent of normal operating speed.

A flywheel uninterruptible power supply, comprising:

• a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder with a diameter that is less than the ideal critical diameter for the steel used to make the flywheel.

A flywheel uninterruptible power supply, comprising:

• a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder that is hardened to centerline structure throughout the axial thickness of the large diameter portion that is greater than 40% martensite.

A flywheel uninterruptible power supply, comprising:

• a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system;
• a motor/generator attached to said flywheel for accelerating an decelerating said flywheel for storage and retrieval of energy;
• wherein said passive radial magnetic bearings are constructed of axially magnetized rare earth permanent magnet rings on said flywheel, said rings are assembled from multiple individual pieces around the circumference and are contained inside a reinforcing portion at each end of the flywheel that cooperates with axially magnetized magnet rings on the stationary portions to provide radial centering force and axial attraction forces.

A flywheel uninterruptible power supply comprised of a solid steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy wherein said flywheel has a cylinder length that is greater than the diameter but the length equal to L meters, diameter equal to D meters and normal rotational speed equal to w radians per second are defined by L<113 (D/w){circumflex over ( )}1/2.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is constructed from steel with both an ultimate strength greater 110 ksi and a toughness greater than 50 ksi (in){circumflex over ( )}1/2.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy wherein said flywheel steel is an alloy containing chromium, nickel and molybdenum.

A flywheel uninterruptible power supply, comprising

• a steel flywheel that spins inside a low pressure housing, and an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy;
• a bearing system for suspending said flywheel for high speed rotation about a substantially vertical axis in said housing, said bearing system having passive radial bearings and an active axial bearing,
• wherein the radial stiffness of the passive radial magnetic bearing closest to the motor/generator is equal to or greater than twice the negative axial stiffness generated by the motor/generator when said flywheel is levitated in normal operating position.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy wherein the flywheel inertia section operates with a maximum stress of greater than 60% of the material tensile yield strength when spinning at normal operating speed.

A flywheel uninterruptible power supply comprised of a steel flywheel that spins inside a low pressure housing and is supported for rotation on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel spins with a tip speed greater than 250 meters per second and the steel in the flywheel has been vacuum arc remelted or electroslag remelted.

A flywheel uninterruptible power supply comprised of a solid steel flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on passive radial with active axial bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy wherein said flywheel has a cylinder length that is greater than the diameter but the length equal to L meters, diameter equal to D meters and normal tip speed equal to v meters per second are defined by L<80 D (1/v){circumflex over ( )}1/2 and L>R (3){circumflex over ( )}1/2.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on full levitation magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a solid steel cylinder with length greater than diameter and during normal operation stores more than 66 kWhs per cubic meter of flywheel outside volume.

A flywheel uninterruptible power supply, comprising:

• a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy;
• said flywheel is made primarily of steel and spins at a speed in normal operation that is calculated to cause a net section failure by use of the NASGROW equation wherein the net section stress is greater than the yield strength for an embedded crack using the width, w, equal to the flywheel length and the thickness, t, equal to the flywheel diameter in under 100,000 cycles from normal fall speed to 10% speed.

A flywheel uninterruptible power supply comprised of a flywheel that spins inside a low pressure housing and is supported for rotation about a substantially vertical axis on magnetic bearing system, said flywheel has an attached motor/generator for accelerating an decelerating said flywheel for storage and retrieval of energy, said flywheel is a comprised of steel and spins at a speed in normal operation that is calculated to cause a failure by the stress intensity criterion in less than 100,0000 cycles from normal full speed to 10% speed wherein the stress intensity exceeds the plain strain fracture toughness assuming the stress and plain strain fracture toughness values at the center of the flywheel.