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Title: Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems

Abstract

Based on prior work at the Lawrence Livermore National Laboratory ambient-temperature passive magnetic bearings are being adapted for use in high-power flywheel energy storage systems developed at the Trinity Flywheel Power company. En route to this goal specialized test stands have been built and computer codes have been written to aid in the development of the component parts of these bearing systems. The Livermore passive magnetic bearing system involves three types of elements, as follows: (1) Axially symmetric levitation elements, energized by permanent magnets., (2) electrodynamic ''stabilizers'' employing axially symmetric arrays of permanent magnet bars (''Halbach arrays'') on the rotating system, interacting with specially wound electrically shorted stator circuits, and, (3) eddy-current-type vibration dampers, employing axially symmetric rotating pole assemblies interacting with stationary metallic discs. The theory of the Livermore passive magnetic bearing concept describes specific quantitative stability criteria. The satisfaction of these criteria will insure that, when rotating above a low critical speed, a bearing system made up of the three elements described above will be dynamically stable. That is, it will not only be stable for small displacements from equilibrium (''Earnshaw-stable''), but will also be stable against whirl-type instabilities of the types that can arise from displacement-dependent dragmore » forces, or from mechanical-hysteritic losses that may occur in the rotor. Our design problem thus becomes one of calculating and/or measuring the relevant stiffnesses and drag coefficients of the various elements and comparing our results with the theory so as to assure that the cited stability criteria are satisfied.« less

Authors:
;
Publication Date:
Research Org.:
Lawrence Livermore National Lab., CA (US)
Sponsoring Org.:
USDOE Office of Defense Programs (DP) (US)
OSTI Identifier:
792729
Report Number(s):
UCRL-JC-137411
TRN: US200223%%885
DOE Contract Number:  
W-7405-Eng-48
Resource Type:
Conference
Resource Relation:
Conference: Seventh International Symposium on Magnetic Bearings, Zurich (CH), 08/23/2000--08/25/2000; Other Information: PBD: 26 May 2000
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; AMBIENT TEMPERATURE; BEARINGS; COMPUTER CODES; ELECTRODYNAMICS; FLYWHEEL ENERGY STORAGE; FLYWHEELS; LAWRENCE LIVERMORE NATIONAL LABORATORY; MAGNETIC BEARINGS; PERMANENT MAGNETS

Citation Formats

Bender, D, and Post, R. Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems. United States: N. p., 2000. Web.
Bender, D, & Post, R. Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems. United States.
Bender, D, and Post, R. Fri . "Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems". United States. https://www.osti.gov/servlets/purl/792729.
@article{osti_792729,
title = {Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems},
author = {Bender, D and Post, R},
abstractNote = {Based on prior work at the Lawrence Livermore National Laboratory ambient-temperature passive magnetic bearings are being adapted for use in high-power flywheel energy storage systems developed at the Trinity Flywheel Power company. En route to this goal specialized test stands have been built and computer codes have been written to aid in the development of the component parts of these bearing systems. The Livermore passive magnetic bearing system involves three types of elements, as follows: (1) Axially symmetric levitation elements, energized by permanent magnets., (2) electrodynamic ''stabilizers'' employing axially symmetric arrays of permanent magnet bars (''Halbach arrays'') on the rotating system, interacting with specially wound electrically shorted stator circuits, and, (3) eddy-current-type vibration dampers, employing axially symmetric rotating pole assemblies interacting with stationary metallic discs. The theory of the Livermore passive magnetic bearing concept describes specific quantitative stability criteria. The satisfaction of these criteria will insure that, when rotating above a low critical speed, a bearing system made up of the three elements described above will be dynamically stable. That is, it will not only be stable for small displacements from equilibrium (''Earnshaw-stable''), but will also be stable against whirl-type instabilities of the types that can arise from displacement-dependent drag forces, or from mechanical-hysteritic losses that may occur in the rotor. Our design problem thus becomes one of calculating and/or measuring the relevant stiffnesses and drag coefficients of the various elements and comparing our results with the theory so as to assure that the cited stability criteria are satisfied.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {5}
}

Conference:
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