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SuperPower, Inc. is a subsidiary of Royal Philips Electronics N.V.

Transmission Level HTS Fault Current Limiter

Dr. Juan-Carlos LlambesC.S. Weber, D.W. Hazelton, M. Marchevsky, Y.Y. Xie, V. Selvamanickam

Applied Superconductivity Conference (Session 4LY07)Chicago, Illinois August 21, 2008

2008 US DOE Peer Review – July 29-31, 2008

SFCL program overview

15.248"

7.362"

15.248"

7.362"

138 kV, 650 kV BIL Bushings

Vacuum Vessel

Pressure Vessel

Matrix Assembly

Inner diameter

Inner Height

HTS Assembly Height

Assembly diameter

Partners

Specifications

• YBCO based, resistive type FCL• 138 kV class device• Fault Current – 13.8 kA• Load Current – 1,200 Arms• Design fault current – 37 kA• Design device response – Recover

to superconducting state after a fault carrying full load current


Prior accomplishments

• Proof-of-Concept demonstrated– MCP 2212 (2004)– 2G YBCO (2006)

• Beta device testing specifications established

• Completed design and testing of HV bushings (SEI)

• Investigated several ‘engineered’ 2G architectures for improved RUL

• Design and laboratory testing of shunt coils to withstand high fault transient loads

• Thermal simulation of RUL process• Weibull plots of ‘standard’ 2G failures• Conceptual CRS & vessel design• Investigated LN2 dielectric properties

2G FCL - Probability of failure for 2G tapes as function of energy input

0.01

0.1

1

10

100

20 25 30 35 40 45 50

Energy [J/cm/tape]

Prob

abilit

y of

failu

re [%

]

Probability of Failure - Test dataProbability of Failure Calculated using Weibull Distributuon


Improvements to shunt coil and contact design

• Shunt coil improvements:– Manufacturing improvements

(easier assembly, more robust coil)

– Mechanical strength – Multi-Layer winding (size

reduction)• Connector improvements:

– Shape optimization to avoid contact hotspots

– Improvement in RUL Time– Improvement in RUL Current– Improvement in consistency of

contact resistance


Tape heating near contact during fault impacts RUL


Correlation between different contact geometries

Total Current (80A peak)

Recovery Voltage

Superconductor’s Current

Straight Thick Contacts(M3-460 Tape):I load = 80 A

RUL = 82 sec.


Recovery Voltage



Recovery Voltage


Straight α-Tapered Contacts(M3-460 Tape):

I load = 80 A RUL = 3.5 sec.

Straight β-Tapered Contacts(M3-460 Tape):

I load = 80 A RUL = 2.8 sec.


Recent KEMA tests• Recent rounds of KEMA testing focused on critical AEP reclosure sequence on

an HTS element

• Straight elements were used

• Improved connector designs were used

• “Standard”, pre-qualified tapes were used

• Test Dates: May 2008, July 2008

5 CyclesFault

13kA/7kA

18 Cycles Load Current

15 sec Load Current

135 sec Load Current

5 CyclesFault

13kA/7kA

5 CyclesFault

13kA/7kA

5 CyclesFault

13kA/7kA

Breaker opens and locks-out

Recovery under NO Load Current

5 CyclesFault

13kA/7kA

160 sec Load Current


2G RUL capabilities tested at KEMA

• ‘Standard’ SC12100 2G wire used

• Test conditions- 37 kA fault

- follows AEP sequence

• Test variables- Shunt impedance

- Number of parallel tapes

- System voltage (v/cm/tape)

- Load Current

16 Tapes8 Tapes

4 Tapes100V

200V

250V

300V

0

50000

100000

150000

200000

250000

Load Pow er (VA)

Total Recovered Power, 2x5 cycles Faults at 37kA with 10 mOhm

Parallel Tapes

Voltag

e


3 x Base-Line Voltage

w/o Load

w/ Load

Achieving RUL is a difficult task

Without load current recovery is very fast

Adding load current makes recovery much more difficult


Base-Line Voltage

RUL

1.5 x Base-Line Voltage

RUL

3 x Base-Line Voltage

RUL

Electrical stress on the tapes can limit RUL

• RUL time can affected by increasing the V/cm on the tape

• Limits of the design optimization are understood


Factors impacting RUL defined by test results

1.67 m-Ohm

5 m-Ohm

100 V200 V

250 V300 V

0

10000

20000

30000

40000

50000

60000

70000

80000

Load Power (VA))

Total Recovered Power, 2x5 cycles Faults at 37kA with 4 Tapes

Shunt ImpedanceVoltage

Sample surface plot of RUL conditions


Ability to predict RUL over wide design space

1.67

m-O

hm

5 m

-Ohm

4Tap

es, 1

00V

4Tap

es, 2

50V

8Tap

es, 1

00V

8Tap

es, 2

50V

16Ta

pes,

100

V

16Ta

pes,

250

V

0100200300

400500

600

700

800

900

1000

Maximun Recovered Load Current

Recovered Current with 2 Asymmetrical 37kA Faults, 5 cycles each

ImpedanceVoltage, #Tapes

Maximum Load Current as a function of shunt impedance, operating voltage & number of tapes


RUL with 90% of the Power recovered within the 2nd and the 3rd 37 kA Faults

Worst case conditions at Tidd can achieve RUL

Full recovery expected with optimal bath conditions


Thank You for your attention!

For more information:

www.superpower-inc.comor

[email protected]

transmission level hts fault current limiter performance. powerful technology. superpower, inc. is a...

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