cryogenic efficiency & losses in ac power machines
DESCRIPTION
Cryogenic Efficiency & Losses in AC Power Machines. Dr. Philip Sargent MIM MBCS CDipAF CEng. Diboride Conductors Ltd. Power Superconductors. Power Superconductors. Cost of Capital – when the superconductor is costly. Lower capital costs, Expensive capital. Lower running costs, - PowerPoint PPT PresentationTRANSCRIPT
Cryogenic Efficiency & Losses in AC Power Machines
Dr. Philip Sargent MIM MBCS CDipAF CEng.
Diboride Conductors Ltd.
Power SuperconductorsRefigeration Energy Consumption
(normalised at 4K)Carnot Thermodynamics
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0 20 40 60 80
Temp (K)
EC
Power Superconductors
How far to "Liquid Nitrogen" regime
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
0 10 20 30 40 50 60 70
Temperature
Ho
w f
ar
to L
q N
2 f
rom
Lq
He
?
Cost of Capital – when the superconductor is costly
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
0 10 20 30 40 50 60 70
Temperature
Ho
w f
ar
to L
q N
2 f
rom
Lq
He
?
Lower running costs,Cheap capital,
Cheap superconductor
Lower capital costs,Expensive capital
Engineering Needs
• Generators, Transformers, Cables, FCLs, Motors, Grid conditioning, power storage
• Capital cost is most important for all of these in deregulated power markets
• Why superconductors?• Higher power density, 100x the current• Smaller• Lighter (MgB2 is 1/3 the density of Copper)• Cheaper to buy and install• Cheaper to operate• Entirely new capabilities (FCLs)
Boron Chemistry
• Pyrometallurgy: Mg + B + heat• Powder in tube in situ• Powder in tube ex situ• Powder in tube ex situ + Mg• Powder in tube + HIP
• CVD Mg + diborane• Electrochemistry: Mg-borates in KCL• Other chemical routes… ??
Materials Requirements
• Magnetic Fields 2-5 T (except cables)• AC use requires T > 20 K (cryogenic cost)• Materials parameters:
• Low cost: ~ 10 $/kA.m
• Practical volumes: Je (Jc 105 A/cm2 )
• Low AC losses: W/kA.m at 50Hz.
• Flexible, low Je / strain sensitivity
Targets
• Copper: 6 – 22 $/kA.m (400 to 100 A/cm2)• Bi2223: 100 – 25 $/kA.m (2002 – 2005)
Device kA/cm2 T $/kA.m
Motor 105 4 10
Generator 105 4 10
Transformer 8.104 0.5 - 2 <10
FCL 8.104 0.2 10
Cable 7.104 <0.5 10-100Dick Blaugher, NREL
Market SegmentationMarket Segmentation
100
1000
10000
100000
1000000
0 2 4 6 8 10
Magnetic Field (T)
Cri
tica
l C
urr
ent
Den
sity
(A
.cm
-2)
Transformers and Fault-Current LimitersMotors, Generators, Energy-storagePower transmissionElectronics
Wire $/kA.m Cost Driver
NbTi (4.2 K, 2 T) 0.90 Materials (Nb)
Nb3Sn (4.2 K, 10 T) 10 Materials (Nb)
Bi-2223 (25 K, 1 T) 25 Materials (Ag)
Y-123 (25 K, 1 T) 4 Capital Plant
MgB2 (25 K, 1 T) 0.8 – 3.6 ? Capital Plant
Competitive Costs
Paul Grant EPRI
1000 100 10 1 0.11
10
100
1000
10000
Y-123 IBAD77K, 0T
Bi-222377K, 0TNKT Target
"Sokolowski Plot" of HTSC Wire Performance and Cost
NbTi4.2K, 2TBi-2212
4.2K, 0TIGC
Nb3Sn4.2K, 12-15 T
$1,000
$100$10 $1 /kAm
Op
era
tin
g C
urr
en
t, Ic
(A
)
Cost ($/m)
Bi-222377K,0T
ASC “50”
Comparative Performance
Paul Grant EPRI
Transformers: a big prizeCost of Ownership in $/kW
2000 ABB SPI Phase I Analysis
Cu (300 K)@ 300 A/cm2
HTS (68 K) MgB2 (25 K)
Losses 60
Cryo -
Wire 5
Total 65
5
25
50
80
5 5
34
8
48
Paul Grant EPRI
First Major Applications
• Current Leads? No.• FCLs ? New capabilities!• Transmission Cables ? • Distribution Cables ?
• Dielectric + thermal + AC lossses• Transformers ? 98% efficient.• Generators ?
• Power stations,Wind turbines?
• Non-Utility Power ApplicationsMotors 68% of industrial powerHalf of that over 750kW
• Power electronics & Cryogenics
Conclusions
• Necessary Partner Technologies• Cryogenics, not 99.999% reliable• Power electronics, why use AC if DC can do it?
• Motors• Higher power density, 100x the current• Smaller, Lighter • Cheaper to buy and install• Transport: ships, trains• Environmentally friendly• Prefer wire not tape! 12 April 2002