Physical principles and applications of inductive HTS...

10th EPRI Conf, TLH, Oct 11, 2011, talk #2, BEST, A.Usoskin

Physical principles and applications of inductive HTS shielded fault current limiting devices with suppressed cryogenic losses

This project is supported within Bruker HTS in part by the German Federal Ministry of Economics and Technology, BMWi, projects no. 0327456 and 03ET1003.

Alexander Usoskin, Alexander Rutt, Tom Withnell, Klaus Schlenga [BEST/BHTS]Mischa Steurer, Sastry Pamidi, Lukas Graber, Jozef Kvitkovic, Tim Chiocchio [FSU/CAPS]

For more details on iSFCL visit our talk #8 to be given by Alexander Henning tomorrow


2

OutlineIn this talk, we are focused mainly on (i) specs, (ii) performance and (iii) potential of 2G HTS assemblies developed for FCL applications.

Implementation of these assemblies in iSFCL is in the talk of

Alexander Henning tomorrow.

A. General topics:

a) nonlinearity

b) response/recovery time

c) impedance ratio

d) cooling consumption

B. Handling of quench propagation:

- V(I)-curves: “amorphous” hot spot

- Quench descretization=> assemblies/modules

- Insulated substrate technology

- Splicing and thermal decoupling

- Mechanical aspects

- Power tests and ac losses

C. Technology and Costs


BHTS coated conductors: basic architecture

3

Cu-envelope, 20 µm SS substrate (50-100 µm)

YSZ buffer (~1.5 µm)

CeO2 buffer (~0.05 µm)

YBCO (1-3 µm)Ag/Au protection layer (0.1-3 µm)

Cu-envelope, 20 µm SS substrate (50-100 µm)

YSZ buffer (~1.5 µm)

CeO2 buffer (~0.05 µm)

YBCO (1-3 µm)Ag/Au protection layer (0.1-3 µm)

+ Low cost PLD+ Highest currents

+ Stable & robustsolution

+ Low cost substrate


Inductive shielded and resistive SFCL

SUPERPOLI FCL-5.5-50 module based on YBCO-

coated stainless steel tubes and Au shunt layer.

Nominal (non-limited) current 2 500 A (ampl.)

Nominal power losses ~ 0.1 W

Fault current, max. 50 000 A (ampl.)

Peak power at fault current: 150 000 W

55 mm

500 mm


Bruker HTS CC Tapes and Modules

(a)40 mm wide CC tapes.

(b, c) SFCL modules based on these tapes.

(d, e) Modules manufactured from 4 mm CC tapes.


Resistive Inductive With Saturable Core

Uac/dc Uac Uac

Im=f(Io)

IoIo

SFCL spectrum


Sequential and avalanche quench

current

voltage

current

voltage

rSFCL:“sequential” quench

iSFCL:“avalanche” quench

i1q

i2q

i3q

iNq

i1q i2q i3q iNq

iq, tot = iq min iq, tot = iq,j j


LN2 consumption in “stay-alone” modus

rSFCL: iSFCL:

40 MVA design in both r- and i-SFCLs (preliminary estimates)

74 m3 per ½ year 4.5 m3 per ½ year

tanktank

Cryotank

Cryo-design:

Cryocooler 850 W of cooling power 50 W of cooling power


Mechanisms of quench development in wide HTS Coated Conductors

2011, May 039 Board Meeting, Alzenau


I(V) curve: iSFCL, Cu losses are subtracted

Test SU240b cu100trns, 11x7CC-mod

0

1000

2000

3000

4000

5000

6000

7000

0 10 20 30 40 50 60 70 80 90 100

voltage 1, V

cu

rre

nt

2, p

ros

p. c

urr

en

t 1

, A

3800A Oscill.

Z1(at 3000A)=0.25 V/30 A= 8.3 mOhms => ΔU = 0.8 V at 100A

Uac

voltage, V

curr

ent,

A


iSFCL: I(V) curves

we call this “amorphous” quench because the hot-spot may be arbitrary shaped.

0

200

400

600

800

1000

0 20 40 60

Voltage (V)

Cu

rren

t (A

)

0,2

1

0,6

2

3

A B C D

0,4


Z(I) curves

0

2

4

6

0 2 4 6

Current (kA)

Resis

tan

ce (

mO

hm

s) 1 2

3

IS-SFCL

IS-SFCL

R-SFCL

Imp

ed

an

ce


Stability of modules and assemblies under quench

13


0 0.2 0.4 0.6 0.8 1 1.20.01

0.1

1

10

100

1 103

1 104

1 105

1 106

1 107

1 108

1 109

Lcr( ),0.004 L

Lcr( ),0.002 L

L

w=4mm: Ic=50%· Ic

w=40mm: Ic=10%· IcPerc

ola

tion length

for

curr

ent,

m

Distance between “micro” defects in across the CC length, m

Lcr( ),w LL

..x

L

w

y1

y

w

w

y1

!floorw

y

X

L

w

i

Long length: current percolation

=Lcr( ),0.02 0.1 4.311043W=40mm:


Quench stability and quench “discretization”: CC tape-shunt assemblies for SFCL

15

RHTS+protect=3-5 Ohms/m

Rsusbstr=0.25 Ohms/m

HTS layer

Substrate (stainless steel)

Insulated metallic substrate

HTS layer

External shunt tape (stainless steel)

Power dissipation (in current driven modus)= 30-100 kW=> overheating within 100 ms

40 mm wide SFCL tapes:

The same power dissipation now occurs in external shunt=> fault duration may be extended to almost 500 ms

current

current

Cu bridges

current

voltage

Cu bridges

<25 mm wide CC tapes seems to be not feasible in such application: # of bridges becomes too high


Main consequences of quench descretization:

1. CC tape carries only 1-2% current after quench

2. As a result CC temperature is slightly abovetransition temperature

3. This results in short recovery time of the entiredevice

16


Quench stabilization: CC tape-shunt assemblies for SFCL

17

HTS tapes with protection layer

Metallic support structure

Rod for mech. connection of modules

External shunts

Sup

po

rtin

gb

asis


Splicing of CC assemblies

18

Insulated metallic substrate HTS layer


Splice resistivity: <50 nOhms x cm2,

Typical splice resistance: 5 nOhms

Power dissipation at 1 kA: 5 mW

No. of splices in 15MVA iSFCL: ~1000

Total power loss: ~ 5 W

current

Cu bridges

together with F. Mumford


Quench stability: Critical length of HTS tape (BHTS+Alstom)

19



Breakdown voltage: ~100V

may be doubled via central bridge

current

Cu bridges



Quench stability: critical length of HTS tape (BHTS+Alstom)

20



current

Cu bridges



Quench stability: thermal decoupling

52

53

54

5555a

56, 57

51

shuntbridge

decoupler

CC tape

HTS layer

assembly


Mechanical aspects

22


Quench test

23

Iq=890 A

Il=480 A

Uac


Over-current test

24

Ipeak=1200 A, Upeak=9,0 V

Emax=4.5 V peak/cm-1

Iq=900 A

Il=480 A

No degradation !


Over-current test

25

At Ipeak=1200 A

Upeak=9,0 V

Iq=900 A

Il=480 AThere is no

degradation after 2000

repeated quenches:


Mechanically stabilized HTS-shunt assembly

Schematic, not drawn to scale


Power Tests of 1st Module: 13MVA 10kV iSFCL: (Alstom-BEST)

Limits prospective 69 kApeak fault to 9 kApeak within very short (millisecond) period.

Enables efficient limitation (factor of 10) of fault current in 5 cycles (100-120 msec).

Exhibits:

• fast response (~0.3 msec).

• fast self-recovery*) after short circuit fault (<0.2 sec).

• withstands large number of limitation sequences.

_____________________*) under 60% of nominal current27

together with F. Mumford, B. Lukasik


Areva – Bruker – Stadtwerke Augsburg Verbundvorhaben „iSFCL“

Self-recovery under current load

Relatively fast self-recovery under current load was observed after 80ms quench. The current load corresponded to 60-80% of the nominal current flowing at normal operation of the iSFCL.

Bruker ASC & HTS

100ms fault

200ms

recovery

F. Mumford, B. Lukachek,A.Usoskin, A. Rutt

Self-Recovery under load


Technolgy of Wide HTS Coated Conductors



US

cle

an

ing

ABAD YSZ buffer

HR

-PLD

CeO

2

HR

-PLD

YB

CO

PV

DA

g o

r A

u

An

neali

ng

Cu

pla

tin

g

150µm

Vacuum, mbar 10-5 10-1 10-1 10-5

Cost floor of processing steps

30

“standard” CC tape


ABAD machine



Task of ABAD template: HIGHLY TEXTURED YBCO films

NSS 160

Operations: Import

4)

3)

2)

1)

d:\Alexander\nss160.RAW - File: nss160.RAW - Type: Phi-scan - Start: -45.00 ° - End: 315.00 ° - Step: 1.00 ° - Step time: 1. s - Temp.: 25 °C (Room) - Time Started: 1 s - 2-Th

FWHM: 3.93 ° - Obs. Max: 268.45 ° - Gravity C.: 268.42 °



FWHM: 3.72 ° - Obs. Max: -2.77 ° - Gravity C.: -2.93 °

0

1000

2000

3000

4000

5000

6000

7000

0

1000

2000

3000

4000

5000

6000

7000

-40 0 100 200 300

Phi - Scale

-40 0 100 200 300

NSS 160

Operations: Import

4)

3)

2)

1)

d:\Alexander\nss160.RAW - File: nss160.RAW - Type: Phi-scan - Start: -45.00 ° - End: 315.00 ° - Step: 1.00 ° - Step time: 1. s - Temp.: 25 °C (Room) - Time Started: 1 s - 2-Th




FWHM: 3.72 ° - Obs. Max: -2.77 ° - Gravity C.: -2.93 °

0

1000

2000

3000

4000

5000

6000

7000

0

1000

2000

3000

4000

5000

6000

7000

-40 0 100 200 300

Phi - Scale

-40 0 100 200 300


CC/module production: HR-PLD

6 beam HR-PLD

6B-PLD machine with deposition area of 0.13m2

Depositionchamber

Optical system


Multi plume HR-PLD (MB PLD)

0%

20%

40%

60%

80%

100%

MOCVD HRPLD PVD (TCO)

ma

teri

al y

ield

, %

- Efficiency of material transfer is about 2 times higher as was expected

- Pulse energy of 600mJ is sufficient for 8 beams

- This indicates further increase cost efficiency and throughput


19.10.201135

Ag deposition / Oxygen loading



Cu plating



Ic Tape Test in Continuous Modus


Mechanical Stability

• Good “mechanics” of stainless steel substrate (650 MPa of yield strength) is translated to the entire CC tape:

- tensile stress, max.: 650 MPa

- bending radius, min.: 6mm

- tape torsion (4mm wide CC): 30° per cm at 40N axial load

• Cost-effective stainless steel substrate(reduces costs by 2-3 Euro/kAm)


0

500

1000

1500

2000

2500

0 5 10 15 20 25 30

B [T]

Ic [

A]

B||c

B||a,b

BHTS tape

t=1.8µm; w =4mm

BHTS

KIT measurements

t=1.8µm; w =4mm

Highest result achieved: Ic = 1925 kA in 4 mm wide tape at B = 18 T, 4.2 K in parallel field, in 4mm-wide tape (characterized by M. Noe, T. Schneider, KIT)

Performance in high fields

Critical currents

Highest Ic achieved in 6m long tape: 500 A/cm-w at 77K, SF

Well-reproducible Ic: 300 A/cm-w at 77K, SF


Homogeneity of critical current 150

100

50

0

Ic, A

0

20

40

60

80

100

0 5 10 15 20 25 30 35 40 45

x (m)

Ic (

A) 1

2Critical current, Ic, versus length coordinate x. 1 – CC tape with local defects marked with arrows and extended defect areas plotted as dashed lines; 2 –CC tape without apparent defects.


Intended product spectrum

Thickness:

• Substrate: 50µm 100µm

• Cu plating: 10µm 50µm

• PEEK insulation: 30µm

Width:

• Final width: 4mm 12mm 40mm

Lamination

• Type: CC+Cu CC+CC

• Width: to 40mm

4mm 12mm

40mm

41


The 800 m length of HTS coated conductors (Bruker-HTS) assembled into “double tape” (Ic>80A=>125A)[SUPER3C]


SUPER 3C – First European CC Cable Project

10/19/2011

As of March 2010:

Successful test of 30-meter long cable

based on PLD grown YBCO tapes.

YBCO (~1 µm)

YSZ Buffer (~1.5 µm)

SS-Substrate (100 µm), non-magnetic

CeO2 Buffer (~0.05 µm)

Au Protective/stabilizing layer (~0.2 µm)

Cu Shunt layer (~20 µm)

YBCO (~1 µm)






YBCO (~1 µm)






Nexans


Cost cake

CC processing steps: cost floor in % per kAm

64%

2%

17%

7%

3%5% 3%

Polishing

ABAD

PLD CeO2

PLD HTS

Protection layer

Annealing

Plating

ABAD

HR-PLD


Summary

45

- Quench descretization (QD) technique allows to manufacture FCL assemblies and modules with short response/recovery time (0.3ms/10ms)

- QD assemblies are based on wide (30-60mm) HTS coated conductor.

- The assemblies allow high (>10) impedance ratio as well as low cooling consumption

- Low ac losses in ring formed stacks are recently found

- Stay-alone operation of SFCL based on QD modules seems to be possible because of low cryo-loss.

- 2G production technology will allow cost efficient FCL solutions


46

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Physical principles and applications of inductive HTS...

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