新型储能材料

Department of Physics & Astronomy
Wind Turbines
This futuristic design also incorporates the magnetic levitation of vertical blades. The first "MagLev" wind turbine is allegedly now been built in China.
Department of Physics & Astronomy
Modern Permanent Magnets
A high performance permanent magnet must have: a high remanence to produce a large magnetic induction a high Hc (Hc ≥ Mr/2) to avoid easy demagnetization a high TC to resist thermal demagnetization. Modern high-performance magnets
University of Delaware ENERGY INSTITUTE SYMPOSIUM March 17, 2008 Newark, DE
Novel Materials for High Energy and Power Density
George C. Hadjipanayis and John Q. Xiao
The superconducting magnetic bearing (SMB) suppresses the vibrations of the flywheel
rotor, whereas the permanent magnet bearing controls the rotor position.
must be of a nanoscale.
Department of Physics & Astronomy
Historical Development of Nanostructured Nd-Fe-B Magnets
100 100 (BH)max (MGOe) (MGOe) (BH)max 80 80 60 60 40 40 20 20 0 0
The signal amplitude from the precessing hydrogen
nuclei is a measure of the total hydrogen content, or porosity, of the formation.
Department of Physics & Astronomy
The predicted (BH)max of the hard-soft composites exceeds 100 MGOe (59 MGOe is
the present record for sintered Nd-Fe-B).
Because the exchange interaction has very short range, the composite material
Energy Generation
• Permanent Magnets • Soft Magnets
• Supercapacitors
Energy Storage
Novel Materials with High Energy & Power Density
George Hadjipanayis John Xiao
Our Challenge
Single Phase Isotropic Decoupled Mr/Ms = 0.5 (BH)max = 12 MGOe
Single Phase Isotropic Exchange -Coupled Mr/Ms > 0.5 (BH)max = 20 MGOe
Nanocomposites Isotropic Coupled Mr/Ms > 0.5 (BH)max > 20 MGOe
New-Generation Magnets: Hard/Soft Nanocomposites
Magnetic exchange coupling allows us to combine the magnetic hardness of rare-
earth compounds with the high magnetization of soft magnetic materials.
Magnetic bearings operate
without friction, require no lubricants, wear-free and virtually maintenance-free.
Waukesha Bearings Research Centre Jülich
Turbomolecular pump with permanent magnetic bearings
1952 1735 1985 Department of Physics & Astronomy
Progress in Permanent MagnetsFra Baidu bibliotek
In the last 100 years, the strength of the magnets [(BH)max and Hc] increased by a factor of 100.
Permanent magnet bearing
Department of Physics & Astronomy
MRI Logging
Magnetic Resonance Imaging Logging uses large
permanent magnets to create a strong static magnetic polarizing field inside the formation.
Energy-Efficient Automotive Applications
Electric Power Steering Motor Hybrid Electric Vehicle Motor
Y. Matsuura. J. Magn. Magn. Mater. 303 (2006).
Department of Physics & Astronomy
are based on Fe- or Co-rich rareearth alloys: Sm-Co, Nd-Fe-B
Fe
and Co provide the high magnetization and high Curie temperature Rare earth metals, such as Sm, Nd, Pr, provide the high anisotropy and coercivity.
Department of Physics & Astronomy
Energy Storage Systems
The energy storage flywheel system proposed by K. Murakami et al. [Cryogenics 47
(2007) 272] employs both permanent magnet and superconducting magnetic bearings.
Y. Matsuura. J. Magn. Magn. Mater. 303 (2006).
In an air-conditioner compressor motor
Department of Physics & Astronomy
Energy-Saving Bearings and Suspensions
This 2.5 MW wind turbine from General Electric
employs a permanent magnet generator, enabling higher efficiency at low wind speeds.
GE product brochure
Energy Efficient Magnetocaloric Materials
• Refrigerants
10000
TM R= 258.4%
High Efficiency Electronic Devices
• Spintronics*
8000
R (Ohm)
6000
4000
2000 -200 -100 0 100 200
Department of Physics & Astronomy, University of Delaware, U.S.A. hadji@udel.edu jqx@udel.edu
Department of Physics & Astronomy
Magnets for Energy-Related Applications
Department of Physics & Astronomy
Applications of Permanent Magnets
In a typical modern car permanent magnets are used in more than 30 places!
Department of Physics & Astronomy
M agnetic Field (Oe)
Department of Physics & Astronomy
Energy Stored by a Permanent Magnet: Energy Product BH
For a given airgap, Vm is inversely
proportional to BH
Department of Physics & Astronomy
Magnetic Levitation Train
Magnetic levitation systems based on permanent
magnets (like "Inductrack", the electrodynamic permanent magnet system) are the most energy efficient and fail safe. Such systems, however, are still under development.
More Efficient Rotors for Electric Motors
Surface Permanent Magnet Interior Permanent Magnet
High-performance
Nd-Fe-B sintered magnets are playing an increasingly important role in automobile and electric appliances driven by the issues of energy saving and efficiency. Inserted permanent magnet rotor has better efficiency than a surface mounted rotor.
Department of Physics & Astronomy
Wind Turbines
Permanent magnets can replace the excitation
winding of synchronous machines and eliminate the need for a mechanical gearbox, coupling the wind turbine to the generator (to adopt a varying wind speed and the constant grid frequency).