Applications of superconductors in electrical...

Applications of superconductors in electrical engineering

Pr B. Douine & Dr K. BergerGREEN - Lorraine University

B. Douine & K. Berger, May 29th 2015, CEA Saclay, France 1Research Group in Electrotechnics and Electronics of Nancyhttp://green.univ-lorraine.fr/

Outline

About the GREEN Motor’s realizations

Flux concentration motor Synchronous motor Axial motor with magnetic coupling Flux barrier motor

Bulk magnetization activities Field cooling process with MgB2 samples Pulsed Field Magnetization with REBCO

B. Douine & K. Berger, May 29th 2015, CEA Saclay, France 2

Research Team

Permanent Members◦ Pr J. Lévêque (team leader)

◦ Pr B. Douine

◦ Pr A. Rezzoug (emeritus)

◦ Dr K. Berger

◦ Dr G. Didier

◦ Dr M. Hinaje

◦ Dr S. Mezani

◦ Dr T. Lubin


PhD Students◦ R. Alhasan

◦ C.H. Bonnard

◦ B. Dolisy

◦ B. Gony

◦ R. Linares

◦ ½ permanent technician

◦ no permanent engineer

Academic collaborations

KIT (M. Noe, F. Grilli)

University of Applied Science Mannheim (S. Elschner)

Saarland University (M.R. Koblichka)

Polytechnique Montréal, Quebec (F. Sirois)

Center for Superconductivity, University of Houston, (P. Masson)

University of Liège (P. Vanderbemden)

University of Alger and Khémis-Miliana (E.H. Ailam)

National Autonomous University of Mexico (F. Trillaud)

French labs: ◦ CRETA-CNRS (X. Chaud) and Grenoble Electrical Engineering Laboratory (P.

Tixador),

◦ Institut Jean Lamour in Nancy (S. Mangin and T. Hauet),

◦ CRISMAT laboratory (J. Noudem and P. Bernstein)…


Industrial collaborations

Jeumont Electric: Project REIMS (Inductor of a machine)

Converteam (now GE): ULCOMAP for ULtra-COmpact MArinePropulsion

DCNS - French industrial group specialized in naval defense and energy

EADS and Airbus Group (Design of superconducting machines for Aircrafts)

Hispano-Suiza and Safran Group

DGA for General Directorate for Armament (Design and realizationof superconducting machines)


Research topics and expertise

Characterization of materials

Modeling (FEM and analytical)

Superconducting motors

Magnetic coupling transmission

Superconducting fault current limiter and electrical network

… other applications


Motors design and, their realization

5 motor’s projects since 2006

4 motor’s realizations since 2006

2 ANR grants (French National Research Agency)

Most of our industrial collaborations


The original idea of the GREEN Superconducting magnetic field concentration motor


1st - study of an inductor in 2002


Coils:• NbTi wires• 260 A• 880 turns

(1) Coils(2) YBaCuO HTS bulks(3) Protection resistor(4) Hall probe connections

1

2

34

2nd - realization in 2006


-9

-6

-3

0

3

6

-0.08 -0.03 0.02 0.07

time (s)

E (V

)

E12E23E31

ULCOMAP Project in 2008


• Zenergy Power GmbH• Werkstoffzentrum Rheinbach GmbH• Futura composite• Converteam (now GE) • Silesian University• University of Nancy

250 kW 2 poles pairs HTS inductor

1500 rpm 50 Hz Bi 2223

400 V Xd : 0.22 pu 30 A

360 A Xq : 0.1 pu 30 K

ULCOMAP Project


Liquid Ne

Gas Ne

Vacuum of the cryocooler

Vacuum of the rotor

ULCOMAP Project


ULCOMAP Project


Total weight: 2 776 kg, Power density: 90 W/kg

New kind of axial HTS motor including a superconducting

magnetic coupling for naval propulsion

June 2014 – B. Dolisy’s thesis

Motor principle

19

ADVANTAGES• Increases the compactness• Better efficiency• Torque transmission without contact No Torque-tubes

Stator yoke withcopper winding

HTS inductorPermanent magnets

Output shaft

Magnetic coupling

Motor

B. Douine & K. Berger, May 29th 2015, CEA Saclay, France

Design and manufactureGoals and difficulties

20

Goals• Study the behavior of the complete system (motor and magnetic coupling)• Validate the superconducting tape modeling• Increase the know-how of the laboratory

Difficulties• Manufacturing the stator without ferromagnetic tooth• Winding of the superconducting coil• Design the rotating parts in cryogenic atmosphere


21

Design and manufactureDesign choices

Restrict the external motor dimensions→ Round HTS coils

∅int = 70 mm minimal curvature diameter∅out = 100 mm

Superconducting coils60 turns / layer

Iron yoke

Mot

orsi

de

Mag

neti

cco

uplin

gsi

de

280

mm

Double layer motor side

• Stator yoke with 6 copper coils Copper coils250 turns

Iron yoke laminated following the radius

• Permanent magnets rotor∅out = 100 mm

Iron yokePermanent magnet

NdFeB

NN

S

S


22

e variable

Cooling by submersion in a liquid nitrogen bath

Vertical machine

e = 5 mm Epoxy cryostat

Liquid nitrogen tank

Output shaft

To load

Slip rings for the alimentation of the inductor

+ Efficient cooling of HTS coils+ Easy installation- High consumption of liquid nitrogen- Bearings of inductor are cold

→ dry bearings

Design and manufactureDesign choices


23

Design and manufactureStator with copper winding

Description Unit ValueThickness of a coil mm 15Opening of a coil - 60°Conductor cross-section mm² 0.75Number of turns per coil - 250Nominal current A 7.5Maximum power kW 1

FeSi Thickness 0.3 mm∅out = 260 mm∅int = 80 mm

Anchorage of the coils


24

Design and manufacture HTS inductor

BSCCO type Hi 240 m

Description Unit ValueThickness of the tape mm 0.25Width of the tape mm 4.4Length m 240Ic @ 77K Self Field A 190

Characterization of a sample (10 cm) of BSCCO tape @77K

BSCCO tape

Iron Permanent Magnets

BSCCO tape0 50 100 150 200 250-10

0

10

20

30

40

50

60

Current (A)

Volta

ge (µ

V)

B applied = 0 TB perpendicular =0.4TCritical voltage


25

Design and manufacture HTS inductor

Description Unit ValueExternal diameter mm 100Internal diameter(minimal bending diameter)

mm 70

Thickness / layer mm 5Turns / layer - 60Length / layer m 16

Current leadInox core

Simple layer (magnetic coupling side)

Double layer(motor side)

Ferromagnetic yoke


26

Design and manufacture Permanent magnets rotor

Description Unit ValueExternal diameter mm 100Thickness mm 10Remanence of the permanent magnets T 1.25

Iron yoke

N

Permanent magnets NdFeBglued on the iron yoke

N

S

S

L. Belguerras, PhD Thesis, « Etudes Théoriques et Expérimentalesd’Accouplements Magnétiques Supraconducteurs », may 2014.


27

Design and manufacture Final assembly

Slip rings

Bearings

Stator

HTS inductor

Permanent magnets rotor

Bearings

Incremental encoder

Incremental encoder

DC motor

Cryostat

Slip rings and brushes

Static torque measure


30

TestsUnder rotation

Back EMF

Single voltage

N = 500 rpmIe = 50 A

0 1 2 3 4 5 6 7 8 9 10 11 120

10

20

30

40

50

Rang harmonique

Am

plitu

de (V

)0 0.01 0.02 0.03 0.04 0.05 0.06-50

-30

-10

10

30

50

Time (s)Ba

ck-E

MF(

V)

ComsolMeasures


Good agreement with the design

31

TestsBehn-Eschenburg model

No-load test Short circuit test

Motor parametersRs ≈ 0.82 Ω Xs ≈ 1.98 Ω

(Xs comsol ≈ 1.78 Ω)

EIinductor EIinductor

Rs j.Xs

Istator

0 10 20 30 40 500

1

2

3

4

5

6

7

8

Inductor current (A)

Stat

or c

urre

nt (A

)

250 tr/min

0 10 20 30 40 500

2

4

6

8

10

12

14

16

18

Inductor current (A)

Back

EM

F (V

)

250 tr/min


Study and realisation of a flux barrier synchronous

superconducting motor

October 2014 – R. Alhasan’s thesis

Motor principle


Magnetic flux

Superconductingcoils

Superconducting screen Cryostat

Copper armature

Superconductinginductor

Influence of the iron


2 cm

2 cm

-0.1 -0.05 0 0.05 0.1-1.5

-1

-0.5

0

0.5

1

1.5

2

z (m)

Br(T

)

Br(z) @ r = Rext + 2 cm

With IronWithout Iron

-150 -100 -50 0 50 100 150-2

-1

0

1

2

Theta (°)

Br (T

)

Br(theta) @ z = 0 and r = Rext + 2 cm

With IronWithout Iron

Without Iron

With Iron

15 cm

6 cm

15 cm

6 cm

Assembly


Inductor coilNbTi ( 4.2K) Ltotal=17 cm

Lactive = 4.5 cmDwire= 0.75 mmN= 850 turns

ArmatureCopper

1680 turnsSwire= 0.4 mm2

Superconcting screenYBaCuO

D =15 cm, e =1 cmCircular Shape

Assembly


Cryostat

Armature

bearings

Inductor

coupling

DC currentmotor

+

Internal vessel

Externalvessel

Fixing of the thermal screen

Thermal screen

Assembly


Tests


-0.1 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.08 0.1-300

-200

-100

0

100

200

300

Temps (s)

E(V

)

Ph1Ph2Ph3

Summary

GREEN has a good expertise in superconducting motors◦ AC losses measurements/modeling are linked to this topic

◦ The characterization of tapes is also needed

◦ Magnetic coupling is a kind of synchronous machine

Most of the motors developed by the GREEN involve bulk superconductors◦ They can trap or screen very high magnetic fields

◦ They are the key for a major technological advance


Outline - High magnetic flux generation with superconductors

How high?

For what purpose?

How it works?

How we made it?◦ Example of field cooling on MgB2 measurements◦ Pulsed Field Magnetization on YBCO @ 77 K


How high?


15 T can be trapped at 30 K using field cooling method

The behavior is different from permanent magnets:◦ Permanent magnets operate at

“constant flux”

◦ HTS operate at “constant current”

Resin impregnated

YBCO pellets

How high?


Record:17 T trapped

Higher fields are theoretically possible

Cryo-magnets are promising, but they are difficult to implement

Resin impregnated

YBCO pellets

M. Tomita et M. Murakami., « High-temperature superconductor bulk magnets that can trap magnetic fields of over 17 tesla at 29 K », Nature 421, pp. 517-520, 2003.

For what purpose?

Electrical machines


H. Matsuzaki et al., « HTS Bulk Pole-Field Magnets Motor With a Multiple Rotor Cooled by Liquid Nitrogen », IEEE Trans. Applied Superconductivity 147 (2), pp. 1553-1556, 2007.

Magnetic coupling◦ Replacing PM by YBCO bulks

T. Lubin et al., « Experimental and Theoretical Analyses of AxialMagnetic Coupling Under Steady-State and Transient Operations », IEEE Trans. Industrial Electronics 61 (8), 2014.

How it works?

Lenz’s law:◦ When a variation of the magnetic field is

applied to a superconductor, there are induced currents

◦ Even if the applied field is null, the currents remain indefinitely in the superconductor producing a magnetic field like a coil

◦ The interaction of the induced currents with a perpendicular magnetic field, (e.g. PM) results in a force according to the Laplace formula Fz = Jθ x Br

Levitation principle


How we made it?

Cryocooler capabilities◦ For cooling the HTS down to 10 K 70W @ 30 K (CH 110, 45 cm bore) 2W @ 10 K (CH 204 with 2 stages) 0.1W @ 5 K (ARS 202 with 2 stages)

◦ The HTS with the cryocooler is put inside the bore of the LTS coil


How we made it?

Cryogenic Hall probes array


How we made it?


By Field Cooling process using:◦ Home made LTS coil 4 T with Ø 10 cm bore (Nancy)◦ Oxford Instruments ±5 T, Ø 7.5 cm bore (Saarbrücken)

MgB2 sample with 4% AgØ 20 mm


Sweep rate influence on the flux jumps

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.00.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

Applied magnetic field, Bapp (T)

Trap

ped

mag

netic

fiel

d, B

trap (

T) 10 K ; 0.05 T/min 10 K ; 0.10 T/min 15 K ; 0.50 T/min 20 K ; 0.05 T/min 20 K ; 0.50 T/min

MgB2 sample produced by SPSØ 30 mm


Sweep rate influence on the flux jumps

-5 -4 -3 -2 -1 0 1 2 3 4 50.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5 10 K ; 0.50 T/min 20 K ; 0.10 T/min 20 K ; 0.50 T/min


Trap

ped

mag

netic

fiel

d, B

trap (

T)

2xMgB2 samples produced by SPSØ 20 mm


Higher trapped fields inside the pellet

0

1

2

3

4

5a

-5 -4 -3 -2 -1 0 1 2 3 4 50

1

2

3

4

5


Trap

ped

mag

netic

fiel

d, B

trap (

T) 10 K ; 0.05 T/min 20 K ; 0.10 T/min 20 K ; 0.50 T/min 25 K ; 0.10 T/min

b

3.63

2.88

2.242.03

2.72

1.95

1.371.75

3.63

2.88

2.242.03

2.72

1.95

1.371.75

4.80

3.92

2.65 2.63

3.44

2.40

1.612.01

4.80

3.92

2.65 2.63

3.44

2.40

1.612.01

10 K0.05 T/min

20 K0.10 T/min

20 K0.50 T/min

25 K0.10 T/min

0

1

2

3

4

5 Top Inside

Trap

ped

mag

netic

fiel

d, B

trap (

T)

2xMgB2 samples produced by SPSØ 20 mm


Higher trapped fields inside the pellet

Pulsed Field Magnetization technique

The most convenient and most common way to magnetize a superconducting pellet is to use a Pulsed Magnetic Field,

It can generate strong magnetic fields while using a relatively small and simple coil,

Thus, the pellet can be directly magnetized into the final application, e.g., a machine.


Experimental apparatus


220 Vac + Rectifier350 Vdc

Capacitor bank115 mF

Thyristor 16 kA max

Experimental apparatus

PFM within an iron core:◦ To reproduce the classical

motor structure

◦ To increase the trapped magnetic field in the HTS


Iron core

Iron

cor

e

Iron coreIr

on c

ore

Iron

cor

e

Bulk Coil

Experimental apparatus @ 77K


B. Gony, K. Berger et al., “Improvement of the Magnetization of a Superconducting Bulk using an Iron Core”, IEEE Transactions on Applied Superconductivity, to be publisher, 2015.

Pulsed current and magnetic field


-250 -200 -150 -100 -50 0 50 100 150 200 250-1.5

-1

-0.5

0

0.5

1

1.5

Capacitor Voltage Vdc (V)

Trap

ped

Mag

netic

Fie

ld (T

)Trapped Magnetic Field as a function of Vdc

0

1

43

2

Magnetization behavior of YBCO


Study of the demagnetization


0 5 10 15 20 25 300

0.2

0.4

0.6

0.8

1

Time (day)

Trap

ped

Mag

netic

fiel

d, B

(T)

B (center)B (edge)

Region 3Self evolution

Region 2AC field applied

120 mT

Region 4AC fieldApplied120mT/

50Hz

Region1Self evolution

(without any applied field)

120 mT

Advantages and future works on PFM

Increased of 35% of the trapped magnetic field by using the iron core,

Maximal current of the discharge 40% lower with the iron core,

The PFM with an iron core will be studied at low temperature using a CH-110 cryocooler.


B. Gony, K. Berger, B. Douine, M. Koblischka, J. Lévêque. “Improvement of the Magnetization of a Superconducting Bulk using an Iron Core.”, IEEE Transactions on Applied Superconductivity, 2015.

New activities at the GREEN Using Fuel cell as a Power Supply for Superconducting Coil


Cat

alys

t Site

s

GD

L

Mem

bran

e

( )2

Flow ChannelH Inlet ( )2

Flow ChannelAir,H O Inlet

( )2

Flow ChannelH Outlet ( )2

Flow ChannelAir,H O Outlet

Cat

alys

t Site

s

GD

L

( )− ( )+

H+

H+

e

e

( )Cooling Water

Inlet

( )Cooling Water

Outlet

( )Cooling Water

Inlet

( )Cooling Water

Outlet

+2H 2H 2e−→ +

+2 2

12H 2e O H O2

−+ + →

IF

C

Sortie H2

M

Circuit de ref roidissement

Charge

humidificateur

T

P

RH

M

H2

FC

8Y1 3A3

PT

6B35B1

M

8Y5

PC

4A3

T

5B6.1

8Y3.1

8Y2

FC

3A6

M

8Y41

T34-35

Réservoir d’eau

1M6

Eau de ville

condenseur

T

Evacuation eau de

refroidissement

Robinet sortie d’eau

T 5B1

condensat

PC M8Y514A6 Sortie air

6B3.1

Circuit d’hydrogène

Circuit d’air

Circuit d’eau

I

Bain thermostaté

CEM



RmηcηaEa

Ec

CDLcCDLa

Icell IcellIa

Ic

VFC [ V ]

jFC [A/cm²]Low current density High current density

Activation losses

Ohmic losses

Concentration losses

OCV~ 1V

Usual working area

~ 0.6V

( ) ( )

( ) ( )

η⋅−=

η⋅−=

dtdCtItIdt

dCtItI

cdlccellc

adlacella

c c,act c,conc

cc,act

oc

cc,conc

L

JRT ln 1F J

JRT ln 1F J

η = η +η η = ⋅ +

η = − ⋅ −

Une cellule :1V, 50A pour 100 cm²

( ) ( ) maaccFC EEV η−η+−η−=



Superconducting coil in liquid nitrogen

PEMFC

Sensor and regulators command

board

Cooling system

CEM®

Air flow controller

New activities at the GREEN A vector magnet generating up to 3 T with 3 axis orientation◦ homogeneity greater than 95% in a sphere of 10 cm diameter


New activities at the GREEN Characterization bench for MgB2 wires: 15-40 K, 1 T, 600 A


New activities at the GREEN Characterization bench for MgB2 wires: 10-40 K, 1 T, 600 A


Thanks for listening!

We are looking for PhD Students…

Pr B. Douine & Dr K. BergerGREEN - Lorraine University

B. Douine & K. Berger, May 29th 2015, CEA Saclay, France 76Research Group in Electrotechnics and Electronics of Nancyhttp://green.univ-lorraine.fr/

Applications of superconductors in electrical...

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