Superconductivity UK

1
Superconductivity UK
Commercial superconductorsfor motors and
generators
Dr. Philip Sargent, Diboride Conductors Ltd.
2
Commercial Wire Tape

• Commercial production
• Niobium alloys (NbTi, Nb3Sn etc)
• B2223 / silver tape - 1st Generation HTS
• Pre-commercial
• MgB2
• Industrial laboratory
• YBCO 2nd Generation HTS coated conductor

3
Superconductors
Tl, Hg(138K)
Transition temperature (K)
Leigh Jarvis
4
More superconductors
YPd2B2C HoMo6S8 (Chevrel) ErRh4B4 CeRu2 heavy
fermion 1991 - K3C60 Fullerene 1994 - Sr2RuO4
2001 MgB2 2001- C nanotubes 2002 - PuCoGa5
(18K)
1980- (TMTSF)2PF6
Nature 6 Mar.2003 - Na0.35CoO21.3H2O
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HTS complex copper oxides
B2223 - Bi2Sr2Ca2Cu3O
YBCO - YBa2Cu3O7
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HTS perovskite ceramics
YBCO - YBa2Cu3O7
B2223 - Bi2Sr2Ca2Cu3O
7
Engineering Implications

• Requires near single-crystal microstructure by
  complex processing,
• Oxide requires furnace treatment in controlled
  oxygen atmosphere, in silver,
• Highly anisotropic resulting tape
• Along and across tape,
• Sensitive to magnetic field direction!

8
B2223 multifilamentary tape -1

• Fill silver tube with precursor powders.
• Reduce by extrusion, swaging, drawing and rolling
  to a mono-filament aligned-crystal wire.
• Restack bundle in another silver tube.

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B2223 multifilamentary tape -2

• Draw multifilament
• Draw to align crystals
• Roll to tape
• Furnace heat treat

10
AMSC Sumitomo

• AMSC Sumitomo have a reciprocal licensing
  agreement

American Superconductor 55 filament (B2223) tape
Sumitomo (B2223) tape
11
AMSC B2223 Manufacturing Plant

• Larger billets, Process automation, Longer
  strands, Multi-dies, Faster line-speed,
  Combination of process steps
• Began volume production in early 2003
• Full capacity could be 20,000 km/year, now 900
  km/year

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(B2223) Critical Currents 2001-02 Manufacturing
variability
32
Manufacturing Campaign for Detroit Edison
gt 150 m lengths
30
Manufacturing Campaign for Customer X (2002)
28
26
24
22
20
18
Frequency
16
14
12
10
8
6
4
2
0
100
103
105
108
110
113
115
118
120
123
125
128
130
133
135
138
140
143
145
148
150
End to End Critical Current, Amps
170 A also demonstrated in short lengths
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B2223 Wire Improvement
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Measured at AMSC UW University of Wisconsin
Measured at AMSC and University of Wisconsin
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19
18
17
Jc (A/cm2, 77 K, 0.1T, //c)
16
15
14
13
12
1994
1995
1996
1997
1998
1999
2000
2001
2002

• Jc of 19.8kA/cm2 (77K, 0.1T, //c) a new level
  of performance for wire with production
  architecture
• Measurement in 0.1 T field avoids self-field
  current suppression

14
Current Distributions in B2223
180 kA/cm2 Regions Observed in AMSC Monocore
Tapes Headroom for Further Current Density
Progress (U. Wisconsin/AMSC)
15
AMSC B2223 Plant History

• Development started in summer 1988
• 10 years (1998)
• AMSC produces 20 km in 200 m lengths with an
  average current of 90 A at 77 K
• 14 years 900km/y plant fully operational
• 15 years 900km/y plant B2223 IPR value of 22m
  written off !

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Price/Performance /kA.m

• How much does it cost to buy the wire to carry
  1000 Amps a distance of 1m?
• Copper 6 /kA.m 22 /kA.m depending on current
  density (400 100 A/cm2)
• Superconductors typically quoted at Jc and at 77K
  and either zero magnetic field or self field.
• Cryogenic OFHC copper can be 0.06 /kA.m.
• NbTi is approx. 0.9 /kA.m in liquid helium.

17
Price/Performance /kA.m
1200
/kA.m
1000
800
Price/Performance Ratio, /kA-m
600
Worlds First HTS Wire Manufacturing Plant
Opened By AMSC
400
200
200 /kA.m
0
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Reduced Manufacturing Costs (/m) and Increased
Wire Performance (current carrying capacity)
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B2223 Commercial Products

• At 50/kAm (77K) price/performance ratio
  significant markets would be enabled (it was
  thought in 1999)
• Utility Generators (gt100MVA)
• Ship Propulsion Motors and Generators (gt5MW)
• Wind Turbine Generators (gt4MW)
• Urban TD Power Cables
• Industrial Magnetic Processing
• Significant worldwide industry in B2223
• American Superconductor, Innova, Nordic
  Superconductor, Sumitomo Electric,
  Vacuumschmelze, Trithor

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Magnetic Field

• High magnetic field reduces current carrying
  capacity
• Lower temperatures enhance current carrying
  capacity
• B2223 must operate 20K 40K for motors which
  have fields 2T
• B2223 at 27K carries twice the current, so /kA.m
  reduces to 100 /kA.m.

20
Saturation in Fe-3Si at 1.6T
1.6
Flux Density, B (T)
21
Peter Lees Cosmic Plot (UW/ASC)
MA/cm2
10
1
0.1
Copper up to 400 A/cm2
0.01
0.001
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Key issues for power applications

• Overall current density Je of conductor, not just
  of superconductor
• Performance in field
• Multiple filaments for AC applications
• Anisotropy of Jc with respect to field direction

• Cost!
• Conductor itself
• Cooling (AC losses)
• Scalability of fabrication
• Mechanical
• Strength, bend radius
• Conductor shape
• tape or wire
• or new motor designs

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Diboride YBCO

• YBCO and similar compounds have had research
  worth billions devoted to their physics and
  processing.
• MgB2 was discovered in January 2001 physics now
  entirely understood.
• Both can be made in
• Tape geometry
• Massive lumps for new motor designs

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Magnesium Diboride
s
39K
p
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Magnesium Diboride
400 /kg
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Making Diboride tape
Simple sintering 700C
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PIT Processing routes for the fabrication of MgB2
wires
B
Mg
IN-SITU

a)
MgB2
EX-SITU
b)
draw to wire
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Powder in Tube
P.I.T.
Final Tape
MgB2
Flat rolling
Université de Genève
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HyperTech CTFF for MgB2
CONTINUOUS TUBE FORMING AND FILLING (CTFF)
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Irreversibility field

• Increase magnetic field capability by metallurgy
• Create pinning defects by controlled alloying of
  MgB2

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10-Meter Long Square MgB2 Wire
Texas Center for Superconductivity and Advanced
Materials University of Houston NASA Commercial
Space Center
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Strain Effect on MgB2 long tape 100 h ball milled
Université de Genève
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In situ BMg with Fe barrier in Monel Sheath
With iron tough to make multifilament- most
likely be cabled , (twisted) monofilaments for
low AC loss conductor, working on Outer sheaths
of Monel, Cu/Ni, and Cu to improve stabilization.
Hyper Tech Research
34
Reasonable properties can be obtained with all Cu
wires, Or with with Nb barriers in Cu.
Multifilament wires can be made
Hyper Tech Research
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Shows ITER barrel wound with over 1 meter of MgB2
wire, all Cu sheath, 1.00 mm diameter wire.
The self field transport current for the coil at
4.2 K was 450 amps, the estimated transport
current at 20 K would be 150-180 amps.
Hyper Tech Research
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First test of an MgB2 pancake

250
MgB
pancake
2
BSCCO pancake
200
150
4.2 K
Critical Current A

100
50
0
3.0
3.5
4.0
4.5
5.0
Magnetic Field T
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Peter Lees Cosmic Plot (UW/ASC)
MA/cm2
10
1
0.1
0.01
0.001
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Magnesium Diboride (MgB2 )

• Advantages
• No weak-link effects, low anisotropy
• Easy to fabricate wires, films lt10/kA.m
  potential
• Challenges
• Tc lt 40 K (77 K applications like cables,
  transformers not viable)
• High field applications such as NMR not viable
• Possible applications in 20-30K range for modest
  field environments, e. g., rotating machinery

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YBCO Coated Conductor

• Rolled, textured Nickel tape (Ni-W)
• Oxide buffer layer, preserves texture
• YBCO (or analogue, e.g. HoBCO), preserves texture
• Near single crystal 100s of metres long
• lt10/kA.m potential

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YBCO Coated Conductor
Sumitomo YBCO-CC
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YBCO
Ni tape
Oxide buffer layer deposition
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YBCO
YBCOprecursor
YBCO oxygenationand conversion
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YBCO
Slitting
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YBCO Coated Conductor tape

• Active programs in US, Japan and Europe
• Examples of results in 2001
• 122 A (75 K) over 1 m by LANL
• World record for meter length
• 50 A over 10 m by Fujikura
• World record for 10 meter length
• Over 60 m Fujikura
• Worlds longest processed tape

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Comparative Development

• YBCO CC
• Fujikura announces YSZ-IBAD process, early 1991
• Ten years later (2001)
• Fujikura produces 10 m with 50 A (77 K)
• B2223
• Work started in summer 1988
• Ten years later (1998)
• AMSC produces 20 km at minimum 200 m piece length
  with an average current of 90 A (engineering
  current density 11,000 A/cm2 at 77 K)

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YBCO CC Technical Issues

• Adequate uniformity over length
• Stability to over-currents or cracks
• Adequate current in MOD films
• Mechanical properties spalling, cracking
• Stability of metal-oxide epitaxial interface
• Deposition rate for ion beam and laser processes
• Thicker than 3 micron YBCO ?
• but must have that 10 /kA.m process!

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B2223 (1G) to YBCO (2G)
48
Price/Performance /kA.m
1200
/kA.m
1000
800
Price/Performance Ratio, /kA-m
600
Worlds First HTS Wire Manufacturing Plant
Opened By AMSC
400
200
200 /kA.m
0
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Reduced Manufacturing Costs (/m) and Increased
Wire Performance (current carrying capacity)
49
AMSC 2G Plant

• 25th Sept. 2003
• ORNL award of 2.5m to AMSC to commercialise 2G
  process
• 1st October 2003
• First tranche of 10m from US DoD and DOE to
  build 2G plant for YBCO-CC tape over 3 years.
• 3rd October 2003
• 44m share issue priced to be used to build 2G
  plant
• but all committed on pre-commercial processes!

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Technology S Curves
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Power Technologies
75y
17y
Performance
HTS g1
Copper-Iron
2003
Effort
52
ConclusionsSuperconductors for Motors

• HTS G1
• B2223 tape
• Diboride
• MgB2 wire
• MgB2 HIPped bars
• HTS G2
• YBCO CC tape
• YBCO cast crystals