Research Papers: Gas Turbines: Structures and Dynamics

Design and Analysis of a Unique Energy Storage Flywheel System—An Integrated Flywheel, Motor/Generator, and Magnetic Bearing Configuration

[+] Author and Article Information
Arunvel Kailasan

Gardner Denver, Inc.,
100 Gardner Park,
Peachtree City, GA 30269
e-mail: Arunvel.Kailasan@gardnerdenver.com

Tim Dimond

Rotor Bearing Solutions International, LLC,
3277 Arbor Trace,
Charlottesville, VA 22911-7580
e-mail: tim.dimond@rotorsolution.com

Paul Allaire

Fellow ASME
Rotor Bearing Solutions International, LLC,
3277 Arbor Trace,
Charlottesville, VA 22911-7580
e-mail: paul.allaire@rotorsolution.com

David Sheffler

Department or Mechanical and
Aerospace Engineering,
University of Virginia,
122 Engineer’s Way,
Charlottesville, VA 22904
e-mail: das2jt@virginia.edu

1Corresponding author.

Contributed by the Structures and Dynamics Committee of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received July 10, 2014; final manuscript received August 26, 2014; published online November 11, 2014. Editor: David Wisler.

J. Eng. Gas Turbines Power 137(4), 042505 (Apr 01, 2015) (9 pages) Paper No: GTP-14-1365; doi: 10.1115/1.4028575 History: Received July 10, 2014; Revised August 26, 2014; Online November 11, 2014

Energy storage is becoming increasingly important with the rising need to accommodate the energy needs of a greater population. Energy storage is especially important with intermittent sources such as solar and wind. Flywheel energy storage systems store kinetic energy by constantly spinning a compact rotor in a low-friction environment. When short-term back-up power is required as a result of utility power loss or fluctuations, the rotor’s inertia allows it to continue spinning and the resulting kinetic energy is converted to electricity. Unlike fossil-fuel power plants and batteries, the flywheel based energy storage systems do not emit any harmful byproducts during their operation and have attracted interest recently. A typical flywheel system is comprised of an energy storage rotor, a motor-generator system, bearings, power electronics, controls, and a containment housing. Conventional outer flywheel designs have a large diameter energy storage rotor attached to a smaller diameter section which is used as a motor/generator. The cost to build and maintain such a system can be substantial. This paper presents a unique concept design for a 1 kW-h inside-out integrated flywheel energy storage system. The flywheel operates at a nominal speed of 40,000 rpm. This design can potentially scale up for higher energy storage capacity. It uses a single composite rotor to perform the functions of energy storage. The flywheel design incorporates a five-axis active magnetic bearing system. The flywheel is also encased in a double layered housing to ensure safe operation. Insulated-gate bipolar transistor (IBGT) based power electronics are adopted as well. The design targets cost savings from reduced material and manufacturing costs. This paper focuses on the rotor design, the active magnetic bearing design, the associated rotordynamics, and a preliminary closed-loop controller.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.


Asif, M., and Muneer, T., 2007, “Energy Supply, Its Demand and Security Issues for Developed and Emerging Economies,” Renewable Sustainable Energy Rev., 11(7), pp. 1388–1413. [CrossRef]
Omer, A. M., 2008, “Energy, Environment and Sustainable Development,” Renewable Sustainable Energy Rev., 12(9), pp. 2265–2300. [CrossRef]
Lior, N., 2010, “Sustainable Energy Development: The Present (2009) Situation and Possible Paths to the Future,” Energy, 35(10), pp. 3976–3994. [CrossRef]
Ebrahim, T., and Zhang, B., 2008, “CleanTX Analysis on Energy Storage,” Cleanenergy Incubator, University of Texas at Austin, Austin, TX.
Bitterly, J. G., 1998, “Flywheel Technology: Past, Present, and 21st Century Projections,” IEEE Aerosp. Electron. Syst. Mag., 13(8), pp. 13–16. [CrossRef]
Hebner, R., Beno, J., and Walls, A., 2002, “Flywheel Batteries Come Around Again,” IEEE Spectr., 39(4), pp. 46–51. [CrossRef]
Hawkins, L., McMullen, P., and Larsonneur, R., 2005, “Development of an AMB Energy Storage Flywheel for Commercial Application,” 8th International Symposium on Magnetic Suspension Technology (ISMST-8), Dresden, Germany, Sept. 26–28, pp. 26–28.
Ahrens, M., Kucera, L., and Larsonneur, R., 1996, “Performance of a Magnetically Suspended Flywheel Energy Storage Device,” IEEE Trans. Control Syst. Technol., 4(5), pp. 494–502. [CrossRef]
Thelen, R., Herbst, J., and Caprio, M., 2003, “A 2 MW Flywheel for Hybrid Locomotive Power,” IEEE 58th Vehicular Technology Conference (VTC 2003), Orlando, FL, Oct. 6–9, Vol. 5, pp. 3231–3235. [CrossRef]
Herbst, J. D., Caprio, M. T., and Thelen, R. F., 2003, “Advanced Locomotive Propulsion System (ALPS) Project Status 2003,” ASME Paper No. IMECE2003-55082. [CrossRef]
Kailasan, A., 2013, “Preliminary Design and Analysis of an Energy Storage Flywheel,” Ph.D. thesis, University of Virginia, Charlottesville, VA.
Reis, P. N. B., Ferreira, J. A. M., Costa, J. D. M., and Richardson, M. O. W., 2009, “Fatigue Life Evaluation for Carbon/Epoxy Laminate Composites Under Constant and Variable Block Loading,” Compos. Sci. Technol., 69(2), pp. 154–160. [CrossRef]
Nehl, T. W., Fouad, F. A., and Demerdash, N. A., 1982, “Determination of Saturated Values of Rotating Machinery Incremental and Apparent Inductances by an Energy Perturbation Method,” IEEE Trans. Power Appar. Syst., 101(12), pp. 4441–4451. [CrossRef]
Hawkins, L., and McMullen, P., 2008, “An AMB Energy Storage Flywheel for Industrial Applications,” J. Japan Soc. Appl. Electromagn., 16(4), pp. 287–293. http://ci.nii.ac.jp/naid/110007132039/en/
Chaudhry, J., 2008, “Rotor Dynamic Analysis in MATLAB Framework,” M.S. thesis, University of Virginia, Charlottesville, VA.
Larsonneur, R., 2009, “Control of the Rigid Rotor in AMBs,” Magnetic Bearings—Theory, Design, Application to Rotating Machinery, G.Schweitzer and E.Maslen, eds., Springer-Verlag, Berlin, pp. 191–228.
Polajžer, B., Ritonja, J., Štumberger, G., Dolinar, D., and Lecointe, J.-P., 2006, “Decentralized PI/PD Position Control for Active Magnetic Bearings,” Electr. Eng., 89(1), pp. 53–59. [CrossRef]


Grahic Jump Location
Fig. 4

Flywheel rotor finite element model

Grahic Jump Location
Fig. 3

Total rotor model, including composite energy storage

Grahic Jump Location
Fig. 2

Inner and outer steel spline ring model

Grahic Jump Location
Fig. 1

Schematic of proposed flywheel design

Grahic Jump Location
Fig. 5

Rotor composite stresses

Grahic Jump Location
Fig. 10

Radial AMB finite element analysis

Grahic Jump Location
Fig. 11

Rotor finite element model

Grahic Jump Location
Fig. 6

Peak stresses over operating speed range compared to failure

Grahic Jump Location
Fig. 8

Thrust AMB finite element analysis

Grahic Jump Location
Fig. 9

Radial AMB inverted design

Grahic Jump Location
Fig. 12

Critical speed map

Grahic Jump Location
Fig. 13

Undamped mode shapes

Grahic Jump Location
Fig. 14

Campbell diagram, rotor with support stiffness

Grahic Jump Location
Fig. 15

Rotor predicted unbalance response

Grahic Jump Location
Fig. 16

Flywheel controller schematic

Grahic Jump Location
Fig. 17

Root locus analysis, radial bearings



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In