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Title: Elastic magnetic composites for energy storage flywheels

Abstract

The bearings used in energy storage flywheels dissipate a significant amount of energy and can fail catastrophically. Magnetic bearings would both reduce energy dissipation and increase flywheel reliability. The component of magnetic bearing that creates lift is a magnetically soft material embedded into a rebate cut into top of the inner annulus of the flywheel. Because the flywheels stretch about 1% as they spin up, this magnetic material must also stretch and be more compliant than the flywheel itself, so it does not part from the flywheel during spin up. At the same time, the material needs to be sufficiently stiff that it does not significantly deform in the rebate and must have a sufficiently large magnetic permeability and saturation magnetization to provide the required lift. It must also have high electrical resistivity to prevent heating due to eddy currents. In this paper we investigate whether adequately magnetic, mechanically stiff composites that have the tensile elasticity, high electrical resistivity, permeability and saturation magnetism required for flywheel lift magnet applications can be fabricated. Lastly, we find the best composites are those comprised of bidisperse Fe particles in the resin G/Flex 650. The primary limiting factor of such materials is the fatiguemore » resistance to tensile strain.« less

Authors:
 [1];  [1];  [2]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Oersted Tech., Sandy, OR (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE Office of Electricity Delivery and Energy Reliability (OE)
OSTI Identifier:
1333929
Alternate Identifier(s):
OSTI ID: 1326442
Report Number(s):
SAND-2015-5397J
Journal ID: ISSN 1359-8368; PII: S1359836816301974
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Accepted Manuscript
Journal Name:
Composites. Part B, Engineering
Additional Journal Information:
Journal Volume: 97; Journal Issue: C; Journal ID: ISSN 1359-8368
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; particle-reinforcement; polymer-matrix composites (PMCs); elasticity; electrical properties; magnetic properties

Citation Formats

Martin, James E., Rohwer, Lauren E. S., and Stupak, Jr., Joseph. Elastic magnetic composites for energy storage flywheels. United States: N. p., 2016. Web. doi:10.1016/j.compositesb.2016.03.096.
Martin, James E., Rohwer, Lauren E. S., & Stupak, Jr., Joseph. Elastic magnetic composites for energy storage flywheels. United States. doi:10.1016/j.compositesb.2016.03.096.
Martin, James E., Rohwer, Lauren E. S., and Stupak, Jr., Joseph. Thu . "Elastic magnetic composites for energy storage flywheels". United States. doi:10.1016/j.compositesb.2016.03.096. https://www.osti.gov/servlets/purl/1333929.
@article{osti_1333929,
title = {Elastic magnetic composites for energy storage flywheels},
author = {Martin, James E. and Rohwer, Lauren E. S. and Stupak, Jr., Joseph},
abstractNote = {The bearings used in energy storage flywheels dissipate a significant amount of energy and can fail catastrophically. Magnetic bearings would both reduce energy dissipation and increase flywheel reliability. The component of magnetic bearing that creates lift is a magnetically soft material embedded into a rebate cut into top of the inner annulus of the flywheel. Because the flywheels stretch about 1% as they spin up, this magnetic material must also stretch and be more compliant than the flywheel itself, so it does not part from the flywheel during spin up. At the same time, the material needs to be sufficiently stiff that it does not significantly deform in the rebate and must have a sufficiently large magnetic permeability and saturation magnetization to provide the required lift. It must also have high electrical resistivity to prevent heating due to eddy currents. In this paper we investigate whether adequately magnetic, mechanically stiff composites that have the tensile elasticity, high electrical resistivity, permeability and saturation magnetism required for flywheel lift magnet applications can be fabricated. Lastly, we find the best composites are those comprised of bidisperse Fe particles in the resin G/Flex 650. The primary limiting factor of such materials is the fatigue resistance to tensile strain.},
doi = {10.1016/j.compositesb.2016.03.096},
journal = {Composites. Part B, Engineering},
number = C,
volume = 97,
place = {United States},
year = {2016},
month = {5}
}