Superconductivity UK Dr. Philip Sargent, Diboride Conductors Ltd. Cables, SMES, Synchronous Condensers and grid stability.

Superconductivity UK

Dr. Philip Sargent, Diboride Conductors Ltd.

Cables, SMES, Synchronous Condensers and grid stability

Large-scale Innovation

R&D

Demonstration

Pre-commercial

Supportedcommercial

Commercial

Technologypush

Marketpull

UK Innovation Systems for New and Renewable Energy Technologies, June 2003. ICCEPT

1967 Superconducting Cable

>100 GW dc, >1000 km !

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

SupermarketSchool Home

Family Car

DNA-to-order.com

Nuclearplant

H2

H2

MgB2

SuperCity Vision

Cables

SiemensNKT Denmark

Cable Projects

• Long Island: 2004, 600m 138kV $30m• Benefit is 3x duct capacity (AMSC)

• Albany/Hudson 450m $26m (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

• 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 lossCheaper to make

Higher thermal lossNo 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

Mansoldo, Jan.2002, PES-IEEE NY.

• “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%”

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-testsemerging marketmature market

Conectus: 2001

ISIS 2002

$38b by 2020

SuperconductivityPower Markets (ISIS)

2003

DC

Power

2015

2010

2020

$20b/y

Generators

• 1970s GE 20MW NbTi in liquid helium• 1990s Japanese 70MW, also NbTi

• 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

• 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 (leading and lagging VARs)

• Voltage support and stability improvement• HTS rotor increases the over-excitation and under-excitation

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

• AMSC 3.7MW• Siemens motor

Timeline

Cryogenics

• Liquid neon for 24-27K operation: useful 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