High Field HTS SMES Coil - Council on Superconductivity · Outer single pancake coil ID, Type A, Type B, Type C , Type D. n - value. 1 . P. V/cm 0.1 . P. V/cm. Single pancakes powered

High Field HTS SMES Coil R. Gupta, ..., BNL CCA2014 S. Korea Dec. 1, 2014 1

Superconducting Magnet Division

High Field HTS SMES Coil

R. Gupta, M. Anerella, P. Joshi, J. Higgins,

S. Lakshmi, W. Sampson, J. Schmalzle, P. Wanderer

Brookhaven National Laboratory, NY, USA

December 1, 2014

IEEE/CSC & ESAS SUPERCONDUCTIVITY NEWS FORUM (global edition), April 2015. Invited Presentation given at CCA 2014, Jeju Island, Korea, Nov. 30 - Dec. 03, 2014.



Overview

… ARPA-E’s mission is to catalyze and accelerate

the creation of transformational energy

technologies by making high-risk, high-reward

investments in their early stages of development

From our sponsor:

We demonstrated a higher field and a higher operating

temperature energy storage coil than proposed before …

12.5 T SMES coil operating at 27 K

This presentation summarizes an aggressive R&D where




SMES SYSTEM Proposal

Superconducting Magnet Energy Storage System

with Direct Power Electronics Interface

Project Goal:

Competitive, fast response, grid-scale MWh

superconducting magnet energy storage (SMES) system

Team member major contributions:

ABB: Power electronics, Lead

BNL: SMES coil and Superconducting switch

SP: 2G HTS manufacture and improved production

UH: Wire manufacturing process research




Focus of the Presentation

Technology for High field HTS SMES coil

– Design, construction and test results

For economic viability of a large scale energy storage system, cost of coated conductor must come down significantly (smart designs can help)

The technology developed could already be applied to special purpose storage system and other applications




SMES Options with HTS

High Temperature Option (~65 K): Saves on cryogenics (Field ~2.5 T)

High Field (~25 T) Option: Saves on Conductor (Temperature ~4 K) High

Temperature

SMES Ring

High

Field

SMES

Ring

Previous attempts:

LTS: up to ~5 T HTS: few Tesla (high temp. to save on cryo)

Our analysis on HTS option:

Presently conductor cost dominates the cryogenic cost by an order of magnitude

High field HTS could be game changer:

Very high fields: 25-30 T (E α B2) Only with HTS (high risk, high reward)

Also: A medium field and medium temperature option

(a new record 12.5T@27K demonstrated, thanks to arpa-e)


mailto:12.5T@27K

mailto:12.5T@27K

mailto:12.5T@27K

mailto:12.5T@27K



The Basic Demo Module

Field: 25 T@4 K (more than ever)

Bore: 100 mm (large)

Hoop Stresses: 400 MPa (>2X)

Conductor: ReBCO (evolving)

Aggressive parameters:




Conductor – ReBCO Tape

12 mm wide ReBCO tape with high strength hastelloy substrate

Measurements at NHMFL (earlier sample)

SMES specs (12 mm):

>700 A@4K

(at any angle)

HTS tape: angular dependence




Large Scale SMES Concept (1)

• A torus would consist of a large number of solenoid module

• Field becomes parallel => less amount of conductor required




Large Scale SMES Concept (2)

Radius: 5 meter, height ~5 meterConsists of double pancakes – same as in demo 10 rings, each consisting of ~1000 double pancakes

GJ scale GRID storage system that can fit in a room!

Moreover, a small B┴ (<0.5 T) for a large B// (30 T) means a

major reduction in conductor cost (~1/5 with an optimized HTS)




Design Parameters of BNL Demonstration Coil

Stored Energy 1.7 MJ

Currrent 700 Amperes

Inductance 7 Henry

Maximum Field 25 Tesla

Operating Temperature 4.2 Kelvin

Overall Ramp Rate 1.2 Amp/sec

Number of Inner Pancakes 28

Number of Outer Pancakes 18

Total Number of Pancakes 46

Inner dia of Inner Pancake 102 mm

Outer dia of Inner Pancake 194 mm

Inner dia of Outer Pancake 223 mm

Outer dia of Outer Pancake 303 mm

Intermediate Support 13 mm

Outer Support 7 mm

Width of Double Pancake 26 mm

High field and big

radius create large

stresses (~400 MPa)




Cross-section of Coil and Support Tube

Conductor used

(ReBCO from SP):

Well over 6 km

(12 mm wide tape)




Grading to Optimize Magnetic and Mechanical Design

Initial 1.7 MJ Design Optimized 1.7 MJ Design

Adjusted for grading:

• Cu thickness in HTS

tape (65 and 100 mm)

• SS tape thickness

(65 and 100 mm)

(more copper in ends;

more SS in center)

End Result:

Improved

performance

Better mechanical

structure and

reduced Bperp

Br

Br

208 182

220

258

215

270

Number of turns per pancake

(for same coil i.d. and o.d.)

(Ma

x 7

.6 T

)

Intermediate

end structure

(Ma

x 7

.1T

)

ax

ial

radial

Current

density

J (A/mm2) Current

density

J (A/mm2)




HTS Single Pancake

Outer: ~210 meter 12 mm tape (258 turns)

• High strength HTS tape,

co-wound with SS tape (for

insulation and added strength)

• Thickness of SS tape and

copper on HTS adjusted to

optimize the performance

V-taps for QA




Two Pancakes Connected with Spiral Splice Joint




Inner and Outer Coils Assembled

Inner Coil (102 mm id, 194 mm od)

28 pancakes

Outer Coil (223 mm id, 303 mm od)

18 pancakes

Total: 46 pancakes




Coils, Test Fixtures and Support Structure

Pancake coils: inner and outer

11 T, 760 A coil and fixture

77 K Test Fixture for outer

Outer Support Tube for

Inner

Outer Assembly Tube for

Outer

Outer Support Tube for

Outer Inner Assembly Tube for

Inner Copper Discs




Inner and Outer Coils

Inner (in support tube) Outer (prior to support tube)




Final Assembly

Outer inserted over inner coil SMES coil in iron laminations




Test Results




77 K Test of a Series of Double Pancakes (inner)

Critical current (1 µV/cm)

Two single

pancakes

powered in

series.




77 K Test of a Series of Double Pancakes (outer)

O1-

1O

1-2

O2-

1O

2-2

O9-

1O

9-2

O3-

1O

3-2

O4-

1O

4-2

O7-

1O

7-2

O8-

1O

8-2

O5-

1O

5-2

O6-

1O

6-20

25

50

75

100

125

150

175

200

225

250Outer double pancake coils

I c (A)

bas

ed o

n 0.

1mV/

cm c

riter

ion

Single pancake coil ID

n-valueType A -CC(160 mm) + SS (25 mm)

Measured value, Beyond rangeType B -CC(160 mm) + SS (50 mm)

Measured value, Beyond rangeType C -CC(120 mm) + SS (25 mm)

Measured value, Beyond rangeType D -CC(120 mm) + SS (50 mm)

Measured value, Beyond range

MT23, Lakshmi, et al O

1-1

O1-

2

O2-

1

O2-

2

O9-

1

O9-

2

O3-

1

O3-

2

O4-

1

O4-

2

O8-

1

O8-

2

O5-

1

O5-

2

O6-

1

O6-

20

50

100

150

200

I c (A)

, n-v

alue

Outer single pancake coil ID

, Type A

, Type B

, Type C

, Type D

n- value

1 mV/cm 0.1 mV/cm

Single pancakes

powered alone

Two pancakes powered in series

Higher Ic in coil at

77K , however,

doesn’t necessarily

translate in to a

higher Ic at 4K

(present conductor)

Four types to achieve

grading (see slide 12)




Double Pancake 77 K Test

2 pancakes with similar

critical currents

2 pancakes with very

different critical current

one pancake good and other

pancake defective

Note: Thorough 77 K test of each pancake

was an important part of a series for QA




2 pancakes 1140 A, 4K

HTS SMES Coil High Field Tests

46 pancakes 350 A, 27K, 12.5 T

Peak

fie

lds h

igh

er

12 pancakes 760 A, 4K, 11.4 T




Double Pancake Coil Test

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60 70 80

I c (A

) @

0.1m

V/c

m

Temperature (K)

Top Coil

Bottom Coil

Nom

inal

des

ign

cu

rren

t: ~

70

0 A

The option of operating over a large range (the benefit of HTS)

Ramp rate

up to 10 A/s




12 Pancake Coil Test

0

100

200

300

400

500

600

700

800

0 1 2 3 4 5

Cu

rre

nt (

A)

Time (sec)

0

50

100

150

200

250

300

350

400

450

500

550

600

650

700

750

800

4:09:07 PM 4:14:53 PM 4:20:38 PM 4:26:24 PM 4:32:10 PM 4:37:55 PM 4:43:41 PM 4:49:26 PM

Cu

rre

nt (

A)

Time

Charge Quench

• Energy (~125 kJ) extracted and dumped in the external resistor.

• 77 K re-test (after quench) showed that the coil remained healthy.

11.4 T in 100 mm bore




Preparation for the Final Test




SMES Coil Run on 5/21/14

0

50

100

150

200

250

300

350

400

14:24 15:36 16:48 18:00 19:12 20:24 21:36

Coil Current

Cu

rren

t (A

)

Time (hh:mm)

12.5 Tesla at 27 K

Record field/energy density in a superconducting

magnet at a temperature of 10 Kelvin or higher

27 K possible

with

liquid Neon

350 Amp

425 kJ

id:102 mm

od:303 mm




Status of ARPA-E SMES Coil

• The design goal was: 1.7 MJ at ~700 A with 25 T at 4 K.

• We tested the unit at several temperatures between 20-80 K,

including the 350 Amp (12.5 T) test at 27 K.

• During one such test, the system tripped due to a data entry error

at ~165 A – well below the earlier magnet test current.

• This trip resulted in damage to a few current leads in the inner

coil. It appears that there was arcing, perhaps during shut-off.

• Since the test was not limited by the field performance, the SMES

coil still has the potential to reach higher field after repair.




Quench Protection




BNL HTS Quench Protection Strategy

-0.2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

745 750 755 760

Vo

ltag

e (

mV

)

Current (A)

Difference Voltage between Coil#2 and Coil#11(1mV = 0.1 mV/cm for 100 m), with offset

Pre-quench phase

Twelve coil test at 4K (~12 T, ~120 KJ)

A multi-pronged strategy developed and used at BNL in various HTS programs:

Detect early and react fast with an advance quench protection system

1. Developed an advanced low-noise electronics and noise cancellation scheme to

detect pre-quench voltage (phase) where HTS coils can operate safely

2. Fast energy extraction with electronics to handle high isolation voltage (>1kV)

3. Use inductively coupled copper discs for fast energy extraction

Drawback: additional energy loss during charging and discharging




0

100

200

300

400

500

600

700

800

0 1 2 3 4 5

Cu

rre

nt (

A)

Time (sec)

0.E+00

1.E+05

2.E+05

3.E+05

4.E+05

5.E+05

6.E+05

0 1 2 3 4 5

I2(A

mp

2)

Time (sec)

0.E+00

1.E+05

2.E+05

3.E+05

4.E+05

5.E+05

6.E+05

2.5 2.502 2.504 2.506 2.508 2.51

I2(A

mp

2)

Time (sec)

Copper Discs for Energy Extraction

Most action

in milliseconds

This fast extraction

provides initial margin

at the critical time

Inductively coupled cooper discs

between two double pancakes




SUMMARY • Even though we didn’t reach the aggressive design goal of 25 T,

in a big aperture (~100 mm) superconducting magnet with large

hoop stresses (~400 MPa) in the first attempt, we did learn

several things in the process beside creating new records.

• This provided a significant experience in using a large amount of

coated conductor (over 6 km of 12 mm wide tape) in a demanding

4K, high field and a high stress application.

• Demonstration of a 12.5 T SMES coil at 27 K is a promising

application of the coated conductor. The earlier most ambitious

proposal was for 11 T at 20 K by Chubu Electric and Furukawa.

• The experience and technologies developed should also be useful

in other applications, such as in NMR, ADMX, accelerators, etc.


Documents

High Field HTS SMES Coil - Council on Superconductivity · Outer single pancake coil ID, Type A, Type B, Type C , Type D. n - value. 1 . P. V/cm 0.1 . P. V/cm. Single pancakes powered