Transcript Superconductivity UK

Superconductivity UK
Cables, SMES, Synchronous
Condensers and grid stability
Dr. Philip Sargent, Diboride Conductors Ltd.
Large-scale Innovation
Technology
push
R&D
Demonstration
Pre-commercial
Supported
commercial
Commercial
UK Innovation Systems for New and Renewable Energy Technologies, June 2003. ICCEPT
Market
pull
1967 Superconducting Cable
>100 GW dc, >1000 km !
SuperCity Vision
Supermarket
School
H2
Home
Family Car
Nuclear
plant
DNA-to-order.com
H2
MgB2
National Climate Change Technology Initiative (NCCTI – “Necktie”)
“Absolutely Zero GHG Emissions by 2050”
George W. Bush
P.M. Grant, The Industrial Physicist, Fall Issue, 2001
Cables
Siemens
NKT Denmark
Cable Projects
• Long Island: 2004, 600m 138kV $30m
• Benefit is 3x duct capacity (AMSC)
• Albany/Hudson 450m $26m
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(Sumitomo/IGC/BOC)
Columbus 300m 2005 (Ultera/Southwire)
Tokyo 100m, 114 MVA (TEPCO/Sumitomo)
Detroit 120m 24 kV, 100 MVA warm dielectric
(Pirelli, AMSC) – vacuum leak.
Copenhagen 100m 36kV, 1.8kA
Southwire 30m 12.4kV 1.25kA, 10,000 hours
Cable Losses
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AC Losses (hysteresis)
I2R losses in joints
Dielectric losses
Thermal conduction losses (side)
Thermal conduction losses (terminations)
Pumping losses (friction of LN)
Cold or Warm Dielectric
Low thermal loss
Cheaper to make
Higher thermal loss
No stray field
www.supercables.com
Warm Dielectric
Coaxial or Trifoil
www.supercables.com
RAND HTS cable study 2002
•Technical feasibility and tradeoffs only!
Pirelli HTS Cable Study 2002
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“The most attractive
scenarios are those where
the higher power transfer
density can be exploited
fully and cannot be
obtained with conventional
technology. In these cases
congestions can be reduced
and system reliability
improved.”
“Modifying cooling
temperature with
refrigeration, transfer
capability can be increased
30-50%”
Mansoldo, Jan.2002, PES-IEEE NY.
Cables Summary
• Losses are roughly equal:
thermal, AC hysteresis, dielectric
• Primary benefits are for reusing scarce duct
space in retrofit in inner cities (10s of km/y)
• Long distance and new AC installations are
infeasibly expensive due to LN cryogenics,
not materials cost – 20x overhead line.
• HV DC cables are another matter…
Conectus Roadmap 4K – 77K
pre-commercial: R&D, prototypes, field-tests
emerging market
mature market
Conectus: 2001
ISIS 2002
$38b by 2020
Superconductivity
Power Markets (ISIS)
2003
2010
DC
Power
2020
2015
$20b/y
Generators
• 1970s GE 20MW NbTi in liquid helium
• 1990s Japanese 70MW, also NbTi
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• 4K liquid helium cryogenics “difficult”
Economics attractive: size, efficiency
Same technology as motors, but BIG
Therefore, follow motor market.
GE/AEP/DOE 100MW project due 2005
(1.8MW generator tested 23 July 2003)
Generator Design
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1/2 length
2/3 diameter
98.6% efficient
cryogenics energy
cost is only 2% of
the total losses
• 50 MW 3600rpm
(Jan.2002)
Synchronous Condenser
Conventional stator
HTS rotor
10 MVAR, 13.8 kV at 60 Hertz
Uses Motor Technology
5MW USNavy motor
36MW motor design
Cross section: air core
5MW rotor
Benefits
• Transient dynamic voltage stability
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(leading and lagging VARs)
Voltage support and stability improvement
HTS rotor increases the over-excitation and underexcitation output limits to its full-rating without loss of
critical clearing time following a transient fault.
Increases capacity: reduces losses
Power factor correction in steady state operation
Stable operation in leading or lagging mode
Less rotor maintenance: no thermal fatigue so used
for peaking as well as base load
Minimizes operating power
Minimizes harmonic content
Delivered to TVA 8 days ago
• 19 Nov. 2003 AMSC “SuperVAR” delivered at the
Hoeganaes steel mill in Gallatin, Tennessee.
• Compensates for the reactive power drawn by the
steel mill’s arc furnace
• North American Electricity Reliability Council (NERC)
cited the need to ensure appropriate levels of
reactive power as the highest priority.
Liquid Neon motors
• Siemens motor
• AMSC 3.7MW
Timeline
Cryogenics
• Liquid neon for 24-27K operation: useful
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for high field BSCCO.
A synchronous machine has effectively a
“DC rotor”,
So AC losses are small in the rotor ,
So gaseous helium has adequate heat
transfer capability at 35 – 40K.
A superconducting stator is not imagined
by BSCCO manufacturers, but may be
OK with Magnesium Diboride.
Flywheel Energy Systems
• Superconducting bearings increase the useful
storage time from minutes to an hour or so.
• Good for power quality control or transmission
support, not load-levelling or peak shaving
• Not as high a power rating as SMES, but more
energy storage
• Pirouette/BNFL in the UK, Boeing in USA
AMSC’s SMES
• 3 MW instantaneous
real power from the
superconductor
magnet NbTi/He
• 8 MVAR of reactive
power from the IGBT
inverters.
“UPS”
SMES for stability
• 115kV Northern
Wisconsin to fix a
network instability
problem
IGBT cooling!
Fault Current Limiters
• FCLs have many
applications
• Save capital costs
on other
equipment
• Many different
designs (resistive,
inductive)
Mårten Sjöström and Diego Politano, ASC 2000
ORNL Model
June 2003
Assumed market growth rates
Motors >370kW
Mulholland ORNL Model
Efficiencies
• Transformers are attractive because of
their efficiency and safety (no oil).
• Generators are attractive because of
their efficiency.
• But much higher value is gained by
reducing capital expenditure by using
Synchronous Condensers, Dynamic
SMES and Fault Current Limiters.
• Therefore, efficiency in these new
devices is not a prime concern.
Thankyou