Advances in the Development of Synchronous Machines with...

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Advances in the Development of Synchronous Machines with High-

Temperature Superconducting Field Winding at Siemens AG

G. Klaus, W. Nick, H.-W. Neumüller, G. Nerowski and W. McCown

IEEE Power Engineering Society 2006 General Meeting

© Siemens AG, CT PS 3, June 2006 2

Content

1. Superconducting machine principles

2. Siemens 400 kW machine

3. Siemens 4 MVA machine

4. Applications for marine vehicles

5. Power generator application

6. Conclusion







6. Conclusion


Substantially reduceSubstantially reduceLossesWeightVolume

EliminateEliminateLimitations in reactive power capability diagramThermal cycling of field windingCoupling of stator and rotor cooling

Savings in fuel costsReduced emissions of greenhouse gases

Smaller, lighter: easier to transport, requires less building space, allows for new drive concepts

Superior steady-state stabilityInsensitive to load changesReduced harmonicsSuperior short-time overload capabilityMore reactive power

No deterioration of rotor winding and its insulation

IncreaseIncreaseEfficiencyPower densityReactive power capabilityStator cooling capacity

Why to use HTS machinesMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Focus on efficiencyUse conventional statorReplace conventional rotor with HTS rotorSame size & mass as conventionalSimilar reactances as conventionalLess HTS conductor required

Two different approaches

Low Power Density

High field HTS rotorStator with air gap copper windingNo stator iron teeth, high current loadLow weight & volumeLow synchronous reactanceMore HTS conductor required

High Power Density

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Potential applications for HTSPotential applications for HTS-- rotating machinery rotating machinery -- future marketsfuture markets

15 rpm 150 rpm 1500 rpm 15,000 rpm

high torquemachines,wind power

gearless ship propulsion

high speed machines,directly coupledto gas turbine

special industrialdrives,ship generator,utility generators

Cold-HeadCold-Head

CompressorCompressor

Power ConverterPower Converter

HTS-RotorHTS-Rotor

Potential fields of application

Compactness

Efficiency

Low mass & Volume

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion







6. Conclusion


400 kW HTS machine

Development started1999

Machine in test operation2001

2002 Successful system test with power converter

2004 Cryogenic cooling system demonstrated and reliability proven

Compactness

Efficiency

Reliability

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Telemetry

Fan

Iron yoke

Stator winding

Core

HTS-windings

Torque

transmission

Rot. cryostat

4-pole design, 1500 rpm, 3~AC, 50 Hz, 400 V

Cut away viewMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Load switching

Constant voltage dip of 10 %

No overshooting voltage when load is switched off

-400

-300

-200

-100

0

100

200

300

400

5 6 7 8 9 10 11

Time (s)

Term

inal

vol

tage

(V)

-2000

-1500

-1000

-500

0

500

1000

1500

2000

Stat

or c

urre

nt (A

)

ΔU = 10%

voltage

current

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion







6. Conclusion


4 MVA HTS machine

Development started

First grid synchronization in test field

2002 2005

System test

2006

Cryo-cooling system

Fan for stator cooling

Air-water cooler (for stator)

Stator

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


ManufacturingMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Short circuit and no load characteristics

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

0 20 40 60 80 100 120Field current (A)

PU te

rmin

al v

olta

ge a

nd

stat

or c

urre

nt

3-phase SC

Open circuit

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Cooling power:required: ~50Wavailable: ~130W

Operational requirements:ReliabilityRedundancy: possibility to change a cooler even during machine operation!

Basic Concept:stationary cold head coupled to heat pipe

Cryo-cooling system

3 GM Coolers (Leybold)

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Losses and efficiencyMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion

η = 96.5 %

0%

20%

40%

60%

80%

100%

Conventional HTS

Loss

es

CryoRotor field ohmicStray loadArmature ohmicCoreFriction & Windage

HTS

η = 98.7 %


conventional machine

2600 2200

3700 1900

2700

1800

7 t

11 t

4 MVA HTS machine

Size & weight matter

vs.80

050

0weight 11 t weight 7 t

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Highlights from Testing, started 13. June 2005:

First synchronization (50Hz) 20th June 2005

Mechanical balancing

HTS winding (rotor) and cryogenic cooling system

Stator air gap winding

Fully underexcited operation cos φ = 0

Efficiency (cryocoolers included): 98.7 %(conventional state of the art: ~ 96.5 %)

Test results achievedMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion







6. Conclusion


Electric power generation on ships

375 t

4.4 m

12.8 m

11.4 m 1.4 m

6100rpm

Gas turbine HTS generator (10 t)

total weight 117 t

7.5 m

13.4 m

20.0 m

6.6 m

400rpm

Diesel Conventionalgenerator (45 t)

total weight 375 t

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Electrical power on individual demand

flexible solution for power supplyintegrated into standardized containers

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Electric motor for ship propulsion

Low speed, high torque4.5 MW, 120 rpm, 330 kNmDevelopment started in 2006Manufacturing until end of 2008

Next project:Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion







6. Conclusion


Siemens retrofit solution

Keep the conventional stator and retrofit an HTS rotor

Depending on generator size, 0.15 to 0.35 % higher power plant efficiency can be obtained

Power output of the conventional stator can be increased due to better cooling conditions

Unique modular approach: generator stators rated 150 – 900 MVA can be retrofitted with only one rotor design (only rotor length and amount of HTS is adjusted)

Realization of competitive excitation response times by employing HTS Roebel conductors

Utility size HTS generators for power generationMachine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


NeorH2

Fundamentals of HTS Retrofit generatorconventional stator

HTS rotor for 900 MVA generator:HTS rotor for 900 MVA generator:Length of active part about 7 mRated excitation current approximately 1760 AAbout 7 km HTS Roebel-conductor Centrifugal acceleration acting on cold part approximately 7200 g

compressorcold-head

stationary pipe

AC ~

DC =

excitation system

rotor with copper windingrotor with HTS winding

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


Field voltage (HTS):

Excitation response

dtIdLIRU f

fff +=dtIdw f2

f∝

750 V750 V750 VCeiling field voltage

HTS w/o Roebel-conductor

HTS with Roebel-conductorConventional

21 pu1.5 pu1 puExcit. response time*

135 A1755 A6700 AField current3620 p.u.21 p.u.1 p.u.Inductance

* time to obtain 0.95 pu terminal voltage after 15% voltage dip

with HTS, ohmic part negligible inductance decisiveinductance proportional to square of field winding turnsfield voltage limited (excitation system, HTS insulation)reduce number of field winding turns to obtain acceptable excitation response times (however, maintain field-mmf)

Solution: HTS Roebel-conductor

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion


HTS Roebel conductor

cross section

9.0 mm

2.5 mm

Decreased field winding inductance by parallel connection of HTS tapes

Transposition ensures uniform current distribution

Field currents in the kA range are possible

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion







6. Conclusion


Conclusion

HTS machines offer significant advantages over conventional machines

Siemens has built and successfully tested two HTS synchronous machines

A third HTS machine project has been started

A first market introduction will be likely with marine applications (All Electric Ship)

First developments have been started on the field of utility size power generators (Retrofit approach)

Machine principles

400 kW machine

4 MVA machine

Marine applications

Power generator

Conclusion

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Thank you for your attention!

Advances in the Development of Synchronous Machines with...

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