Magnetic Materials Enabling Electrified Aircraft Propulsion
Transcript of Magnetic Materials Enabling Electrified Aircraft Propulsion
1Advanced Air Transport Technology Project
Advanced Air Vehicles Program
National Aeronautics and Space Administration
www.nasa.gov
Dr. Cheryl Bowman, Hybrid Gas Electric Propulsion Technical Lead
NASA John H. Glenn Research Center
Energy Tech 2017
October 31, 2017
Cleveland, OH
Magnetic Materials Enabling Electrified Aircraft Propulsion
Research Team:
Drs. Alex Leary, Ron Noebe and Randy Bowman
Vladimir Keylin and Grant Feichter
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Outline
• How materials research enables electrified aircraft propulsion
• Definition of magnetic materials
• How magnetic materials are used in electric machines and electronics
• Hard/Permanent Magnetic Materials
• Soft Magnetic Material
• Application potential for new soft alloy class
• Manufacturing status and component demonstration status
Electrified Propulsion Requires Increase in Performance
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Power Electronic
Higher Operating Frequencies
Lower loss Filtering
Higher Efficiency
Motor/Generator
Magnets for Power Density
Thermal Management
Adv. Manufacturing
Insulation
Batteries/Energy Storage
Cell Chem for Power Density
Pack Eng. for Safety
Materials Research Enables Electrified Propulsion
Vehicle Concepts Informing Materials R&D: • STARC-ABL aircraft concept closes with net fuel burn benefit IF advanced power
components can be developed and implemented
• Other electrified aircraft concepts will require similar improvements
BLI Fans
Distortion Tolerant
Power Architecture
Insulation for HiVolt
Better EMI Protection
Adv. Conductors
Flight Controls and
Mission Profiles
HEIST studies
Concept NRAs
Advancement in Component Materials is Required
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Coercivity (A/m)
10-1 100 101 102 103 104 105 106 107
Sa
tura
tio
n M
agn
etiza
tio
n (
T)
0.0
0.5
1.0
1.5
2.0
2.5
FeCo
REPM
Steels
FeNi
Alnico
Definition of Magnetic Materials
All materials have magnetism; Ferromagnetic materials are useful
• Soft magnets—easy domain wall movement with minimal energy—tight loop
• Hard/Permanent magnets—more energy required to magnetize and demagnetize but
maintain their magnetic alignment
Magnetic Materials are High Performance Alloys
Br
Hcmi
BS Mag Saturation, strength
External Field Strength, H
To
tal F
ield
,
B
Hc Coercivity,
resistance to de-mag
mi Permeability,
ease of magnetization
• Chemistry, Grain Size, Domain Size,
Crystallographic Orientation are key
features
• Properties can vary with product form
• Handling can affect properties
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Magnetic Materials in Electrical Machines
Hard Magnets Provide Constant Magnetic Field
• Rare Earth Permanent Magnets (REPM) are the highest coercivity magnets, so have
the highest resistance to demagnetizing fields
• NdFe class has highest magnetic strength
• SmCo class has highest temperature resistance
• FeCo (Hiperco) soft magnetic alloys have the highest saturation strength and are
used in applications where mass is critical
• Other soft magnetic alloys can yield lower losses, especially at high frequency
• Hard magnets provide constant
magnetic field which can greatly
improve motor specific power
• Soft magnets provide magnetic field
shaping
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Soft Magnetic Materials in Electrical Components
• Soft magnetic materials are the building block of chokes, filter inductors,
transformers and EMI shields
Soft Magnets Enable Power Conversion/Conditioning
• Thin laminations reduce eddy current losses
• Reduced coercivity decreases hysteresis losses
• Desirable permeability is component dependent;
e.g. low permeability for inductors, high
permeability for transformers
Core Flux
Leakage
Flux
• Wide band-gap semi-conductors enable
higher power and higher frequency
applications
• Soft magnetic materials must be chosen to
compliment the particular power component
application
Transformer
Most devices/components benefit from higher
operating frequencies, which results in higher power
densities (higher output and lower volume)
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Nanocomposite Alloys Fill Void in Electronics Design
Nanocomposite alloys have higher saturation & temperature capability than
amorphous alloys and tailorable permeability
New Alloy Class with Good Design Characteristics
Classes of
Materials
Relevant
Frequency
Range
Max
Saturation
(T)
DC
Permeability
Resistivity
(Ω-cm)
Useful
Temperature
Range (°C)
Bulk Alloys DC – 1 kHz 2.5 102 - 105 0.5 x 10-6 <500
Powder Core 10 – 500 kHz 1.6 20 – 500 1 <200
Ferrites 10 kHz – 100
MHz
0.5 100 – 5000 102 - 108 <300
Amorphous Alloys DC – 100 kHz 1.5 105 130 x 10-6 <200
Nanocomposites DC – 100 kHz 1.9 100 - 105 110 x 10-6 <400
Saturation—2nd
only to bulk
alloys
Frequency—up
to 100 kHz
Resistivity
higher than
bulk alloy
Temperature—
2nd only to bulk
alloys
Tunable Permeability—controlled
by strain or field annealing
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Amorphous and Nanocomposite Alloy Production
Substantial Soft Magnetic Alloy Development Potential
• Melt Spinning Fe-base, Co-base or Fe-Ni alloy with “glass former” creates amorphous
alloys that are naturally thin with lower losses at high frequency
• Selective nanocrystallization of magnetic
phases makes a nanocomposite that is still
naturally thin with low losses at high
frequency as well as
• Better temperature stability
• Crystallization in magnetic or strain field
allows selective permeability
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Nanocomposite Alloy Development
Substantial Soft Magnetic Alloy Development Potential
Finemet is a first generation Fe-based nanocomposite which is commercially available
Next generation Fe-based nanocomposite will offer
• Improved electrical stability such as a more square B-H curve, which allows constant
inductance over a wider field
• Stable permeability also improves performance over a wider range
of DC bias conditions
• Higher temperature stability
Co-based nanocomposite alloys have better
mechanical properties
• Alloying and processing studies are striving
to maximize magnetic properties
Fe-Ni alloys are being explored to potentially produce
lower cost alloys
Hc
BS
H
B
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Nanocomposite Alloys Transitioning to Components
Transitioning Alloys from Lab-scale to Components
• NASA Glenn operating a medium scale spin-
caster producing 3 kg of ribbon up to 50 cm wide
• Producing Fe- and Co-based alloys in quantities
and sizes sufficient for relevant-sized
components
• Completed 50-kg delivery of Co-based alloy
ribbon for DOE inductor program
Casting Co alloy
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Ready to Design, Build, and Test for Specific Applications
Substantial Component Development Potential
Example Nanocomposite has lower losses
than a powder core in comparable application
Working practical fabrication
issues associated with
manufacturer-ability
Designed a prototype to replace
a ferrite core inductor in a 20
kHz NASA controller—bench
testing shows 40 times lower
losses per inductor
COTS
powder core:
50 Hz
100 Hz
200 Hz
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Ongoing Partnerships
Transitioning Alloys from Lab-scale to Components
• Advanced Inductor for DOE Motor Program- Partners included NETL (DOE), Eaton, and Carnegie
Mellon
- Started in Sept 2017
- Developing a 3 MW-motor for gas industry applications
- Delivered 50 kg of a custom alloy.
- Producing test data to support inductor design.
• Ohio Federal Research Network- Ohio partners include Case Western and Youngstown
State
- Developing high-temperature magnetic materials
• Colorado School of Mines (CSM)- NSF-funded 1st principle modeling of
magnetic materials
- Hosted a CSM summer student at GRC
• Interagency Advanced Power Group
(IAPG)- Coordinates research activities across
multiple federal agencies
- Established an “Electrical Materials”
panel in 2016 under the Electrical
Systems Working Group
• Fort Wayne Metals- Establishing industrial production capabilities for
commercialization of these new materials
• SunShot National Laboratory Multiyear
Partnership (SuNLaMP)- Partners included NETL (DOE), NC State, and Carnegie
Mellon
- Started in March 2016
- The SunShot program is targeting solar PV cost reduction and
new technology development, both of which are required to
achieve dramatically increased penetration of solar energy
by the year 2020.
• NASA EPSCoR- University of Alabama
- Atomistic and micro-magnetic models to
guide alloy development efforts
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Take Away Points
• Materials Development is important for continued component
improvements
• There is significant development potential remaining in soft
magnetic materials which correspond to the significant
development potential remaining in power electronics in general
• Component designers should not limit themselves to “off the
shelf” passive component designs when planning for future power
electronic components or systems
Electrified Propulsion Requires Increase in Performance
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