160610 esas reis ho - unibo.it · t. reis, j. oswald, b. oswald, a.t.a.m. dewaele oswald...

TR 2016 ESAS International Summer School 1

T. Reis, J. Oswald, B. Oswald, A.T.A.M. deWaeleOswald Elektromotoren GmbH

www.oswald.de

superconducting

rotating machines


Why can SC be useful in a motor/generator

how do motors work

what are todays limitations for motors

where can SC be used in a motor

topologies and examples

cryogenic aspects

outline


Karl Oswald und Sohn

foundation 1909 in Miltenberg am Main


Oswald Elektromotoren GmbH


Oswald Elektromotoren GmbH

50 kW … 2 MW customized motors/generators … 200.000 Nm


motor / generator

FJ

B

J

F

functional principle of a homopolar motor

resulting lorentz force on current in external field


motor / generator

http://www.fh-sw.de/sw/fachb/et/labinfo/em/iSEE/dreh.htm


motor / generator

spacial arrangement of coils number of slotsnumber of polesnumber of phasesconnectionpowerspeed


motor / generator

3 m

60.000 Nm 2 tons

350 Nm

P~M⋅f/p P: Powerf: Frequencyp: number of pole pairs


motor / generator

P~M⋅f/p

n [rpm]

Is

M

P

U

Up

Umax

rated operation



how do motors work




cryogenic aspects

outline


motor / generator

RPHI


motor / generator

external field

flux in material

in air


motor / generator

NdFeB:B = 1,1 - 1,3T

iron:Bmax = 2T

magnetically softmagnetically hard


motor / generator

NdFeB:B = 1,1 - 1,3T

iron:Bmax = 2T

80% coverage 50% coverage

Flux densityin Airgap:B = 1T

PM-Synchonous motor:All parts fit perfect together


motor / generator

0

10

20

30

40

50

60

70

80

90

100

1980 1984 1988 1992 1996 2000 2004 2008 2012 2016

%

DC

AC asynchron

AC synchron

DC motorsuntil 80‘s

development of inverter technology:efficient asynchronous motors


motor / generator


motor / generator

0

10

20

30

40

50

60

70

80

90

100

1980 1984 1988 1992 1996 2000 2004 2008 2012 2016

%

DC

AC asynchron

AC synchron

PM-synchronous motors


motor / generator

development of NdFeB-Magnets decisivefor synchronous technology:

- increased force density (>20%)- higher efficiency (some %)- more compact (> 1 size)- better dynamics (>30%)- …


motor / generator

Que

lle: S

chul

er/B

MW

power: 390 kW

torque: 15500 Nm

weight: 2310 kg


motor / generator

Advantages of PM-Motors:

- High force density

- Passive rotor

- High dynamics

… enables many

new applications

4 poles 16 poles


motor / generator

0

10

20

30

40

50

60

70

80

90

100

1980 1984 1988 1992 1996 2000 2004 2008 2012 2016

%

DC

AC asynchron

AC synchron

next developments?

What is needed?


motor / generator

Quelle: Vestas

no nc solutionsso far…


motor / generator

- solutions for so farunfulfillable requests

- independance oncritical resources

- new applicationspossible

- usage of newtechnologies andmaterials for buildingmotors

- improvement ofoperating parameters

- …


motor / generator


motor / generator

superconducting

transmission linessuperconducting

propulsion motors

superconducting

generator + turbine

power electronics

batteries

EADS/Airbus concept: Paris Air show 2013


New applications are arising:

- Increased acceleration rate

- Reduced Size

- Increased power density

Common background:

even applications are in development

years to come into market…

motor / generator



how do motors work




cryogenic aspects

outline


motor / generator

el. power

iron losses

copper losses

copper losses

stator

rotor

friction, iron losses

mech. power

?


motor / generator

�: ��turns�: ��

��

limiting factors:- available space for magnetic system- space needed for application- cooling system

�~��

engineering current density: �~��

� �


motor / generator

Bilder von Spulen!j / A/mm² B / T cooling

2 - 4 0,05 conduction

5 - 10 0,1 water jacket

Quelle: Superpower


motor / generator

j / A/mm² B / T cooling



20 - 40 1 hollow conductor

Quelle: Superpower


motor / generator





> 150 > 10 superconductor

Quelle: Superpower


motor / generator

current density:

superconducting layer> 60.000 A/mm²

tape> 600 A/mm²

engineering> 150 A/mm²





> 150 > 10 superconductor

Quelle: Superpower


motor / generator


motor / generator

Quelle: Izumi, Japan

trade off:

- critical current

- operating

temperature

- availability

- price

- dimensions

- losses

- …



how do motors work




cryogenic aspects

outline


motor topologies

AC – nc asynchronous rotor

nc – PM-Rotor – sc

nc – rotor sep. excited– sc

nc – reluctance rotor – sc

all sc motor

… and some more:

homopolar

axial flux

transversal flux

…reference motor


reluctance motor

- Diamagnetic rotor

- Passive rotor – no power transmission

- Cold rotor

- Iron in rotor obligational and close to SC

- Relative low force density

- No limitations in operation

- Complex rotor structure – speed limitations

Force density:

130% compared to nc PM-Motor


excited Synchronous Motor

- Active SC coils in rotor (DC application)

- power transmission (many kA!)

- Cold rotor

- Iron in rotor (partially) useless (>2T?)

- Active influence on excitation


and minimum sizing (-> MW)

Force density:

> 200% compared to nc PM-Motor


PM motor

- Active SC coils in stator (AC application)

- Passive rotor system

- Cold stator

- Iron in stator (partially) useless (>2T?)

- Flux control for high speed

- Cryostat for rotating fields

Force density:



fully SC motor (exc. rotor)


- Active SC coils in rotor (DC application)

- Cold stator and rotor

- Iron in stator and rotor (partially) useless

- Power transmission to rotor (many kA!)

- Active influence on excitation


and minimum sizing (-> MW)

Force density:



fully SC motor (bulk rotor)


- Bulk SC in rotor (DC application)

- Cold stator and rotor


- Passive rotor

- Magnetizing device needed

- Flux control for high speed or dynamic

adaption of magnetization

Force density:



Homopolar motor

- Active SC coils in stator (DC application)

- Rotor made of conductive material

- Cold stator


- Power transmission (many kA!)

at least one at large diameter !!!

- Easy speed control

Force density:




how do motors work




cryogenic aspects

outline


SC motors / generators

power / MVA speed / rpm application

Converteam UK 1,79 214 hydro generator

Siemens Germany 4 120 ship propulsion motor

Converteam UK 8 12 wind generator

AMSC USA 36,5 120 ship propulsion motor

Siemens Germany 4 3600 industrial generator

Converteam UK 0,5 nn demo generator

IHI marine Japan 0,365 200 ship propulsion motor

Doosan, KERI Korea 1 3600 demo motor

Doosan, KERI Korea 1 1800 demo generator

Kawasaki Japan 1 190 ship propulsion motor

AMSC USA 8 1800 generator

AMSC USA 5 230 motor

Oswald Germany 0,2 650 industrial motor


SC specific features:

- „R=0“, only inductance ofexcitation coil

- feeding of high rotorcurrents

- flux guidance in yoke andteeth (saturation!)

- mech. power transmission

- …

increase of „B“ by SC-excitation coils in the rotor

motor topologies


magn. air gap

cooling

HTS-coilcryostat

pole core


- thermal insulation of rotor

- feeding of coolant

- temperature drop > 200K

Quelle: Siemens

advantage: DC-application

no losses in SC

motor topologies

increase of „B“ by SC-excitation coils in rotor


Quelle: GE

SC – motors:GE

1970’s - Westinghouse5 MW, 4.5 K NbTi Superconductor

1980’s -General Electric20 MW, 4.5/8 KNbTi/Nb3Sn Superconductor

1990’s – Westinghouse STC1 MW, 20 KBSCCO Superconductor


Quelle: Siemens Quelle: Siemens

Quelle: Siemens

HTS II:

2002 - 20074 MVA3600 rpm

high speedlongterm operationsince 2009

HTS I:

1999 - 2002400 kW1500 rpm

technologydemonstrator

HTS III:

2006 - 20104 MW120 rpmhigh torque: 300 kNm

SC – motors:Siemens


Quelle: Siemens

HTS I:

1999 - 2002400 kW1500 rpm



Synchronous motorBi2223/AG tapeAir gap copper stator

Operating temperature 27K„plug and play“

Ne cooling system


Quelle: Siemens

HTS I:

1999 - 2002400 kW1500 rpm




Quelle: Siemens

HTS II:

2002 - 20074 MVA3600 rpm

high speedlongterm operationsince 2009



first operation in test rig

Quelle: Siemens

Quelle: Siemens

Siemens 4MW HTS II 2007 at test rig:

- rotor at 25K (fl. Ne)

- motor weight -30%

- coils made of Bi-2223

- first grid synchronization 2009

- efficiency +2%

- losses -50%

- > 5000 hours of operation withoutdegradation of SC


GE Hydrogenie:

2006 - 20131,7 MW

214 rpm

HTS-coils on rotor

cooling with He-gas-feedthrough in shaft

Quelle: GE

SC – motors:GE


AMSC ship propulsion:

36,5 MW120 rpm

Quelle: AMSCQuelle: AMSC

SC – motors:AMSC


SC – motors:Oswald

SDYN110:

400 kW77 K, lN 2

reluctance type motorpower density 130% compared to nc PM-motor



Plastic:Po = 229 kWPa= 470 kVA

Ideal SC:Po = 345 kWPa= 400 kVA

Real YBCO:Po = 256 kWPa= 420 kVA


SC – motors:wind power

Quelle: tecnalia

Superturbine:10MW offshore by 2020

ecoswing:3MW onshore retrofit


Quelle: AMSCQuelle: Siemens

Quelle: eco5

10MW sc 4MW pm8MW ind

advantage SC motors:

volume-40…60%

weight-50…70%

power density+100…150%

dynamics+150…200%

efficiency…99,9%

SC – motors:DC-application in rotor


motor / generator


- cooling in the not movingparts

- AC-application of SC:

many constraints!

increase of „A“ by SC-field coils in the stator



SLIN:

45 kN77 K, lN 2

stator coils BSCCOpower density andacceleration: 200%



SMFS:

40 kW, 665 rpm, 575 Nm77 K, lN 2

PM-motor with SC statorpower density 200%compared to nc PM-motor



how do motors work




cryogenic aspects

outline


SC losses in AC application

low temperature – SC:

in mixed phase flux lines through SCwith each elementary flux quantum:h/2e = 2,07 10-15 Tm²


- transport current causes Lorentz force on flux lines

- drifting movement consumes energy, appearing as el. resistance

- defects in cristal lattice can pin fluxlines

- flux lines are pinned until criticalcurrent density, resistance disappears



B

I

B

B?

SL: 5x 1µmStack: 1,3mm

I I?

losses in single tapecan be calculated analytically

good analytical approximationfor ideal stack

behavior in coil shape, with ext. fields, alternating current, shielding, …?



influence oncrit. current


Losses in single tape in selffield can be calculated

Approximation for stack (part of coil in slot):

- Losses due to current transport in selffield:

- Losses due to external magnetic field:



RPHI

B

B



BB

Calculation of magn. Flux within SC


with material data and boundary conditions (ext. field, current, temperature, …):losses in SC can be estimated.



with material data and boundary conditions (ext. field, current, temperature, …):losses in SC can be estimated.

Lo

ss i

n S

C a

nd

iro

n[%

of lo

ss a

t rat

ed v

alu

es]

Torque [kNm]

262218

20

40

60

80

100

0 141062

AC total

V Fe

P trans

P hyst



calorimetric measurementof SC losses:

- ext. magn. field

- current transport

- self field

- temperaturedependence




losses with current transport in Racetrack-coils in selffield:measurement (kalorimetric und elektrical) vs. calculation

Additional losses(quench)



Cooling technology:

• Direct contact / heat conduction

• Cooling with Gas, Liquid, …

heat capacity, evaporation energy, …

closed, open loop, …


cooling system of SC in stator

optimal operation pointdepends on:

- SC material properties

- recooling of losses

- specifications

- size

- …


Quelle: Sumitomo

cooler:input power/cooling power


cryocooler



Quelle: CryoZone

fan



1. Ventilating system

2. Cold head

3. Power terminal (warm)

4. Transfer lines to motor

5. Sensoric terminal (cold)

6. Power terminal (cold)

7. Power transmission (cold-warm)

8. Heat exchanger


operation temperaturedepends on load:

lossescooling capacity




Our goal:Turn white fog into black box


power:speed:torque:efficiency:dynamics:YBCOcc-tape:

40665575

99,6>10.000

400

kWrpmNm%rpm/sm



potential of SC-motors:

- power density> 200%- dynamics > 300%- weight/size 40…60%- efficiency …99,7%- availability of material

applications:

- mobility (ship, vehicle, plane)- generators- industrial drives


160610 esas reis ho - unibo.it · t. reis, j. oswald, b. oswald, a.t.a.m. dewaele oswald...

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