cryogenics day converteam - research councils uk

High Temperature Superconductivity (HTS) Technology Requirements

Clive Lewis, Advanced Technology group

CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS© 2010 Converteam UK Ltd. All rights reserved COMMERCIAL IN CONFIDENCE Feb 2008 2

Contents

Introduction to Converteam

HTS Direct Drive Wind Turbine Generator

OPT Powerbuoy – HTS Linear Wave Generator

POSEEIDON – Electric ship propulsion utilising HTS technology

HYDROGENIE – HTS Hydroelectric Generator

Infrastructure requirements

Key enablers for HTS rotating machinery

CUSTOMISED TECHNOLOGY FOR CUSTOMER SUCCESS© 2010 Converteam UK Ltd. All rights reserved COMMERCIAL IN CONFIDENCE

CONVERTEAM AT A GLANCE 1/2

Power generation Power transmission& distribution

Converteam

Marine

Industry

O&G

Converteam: a new name for a company with more than 100 years experience in power conversion

Converteam is an engineering company providing customised solutions and systems converting electrical energy into productive performance

Energy


CONVERTEAM AT A GLANCE 2/2

Converteam provides solutionssystems

These solutions are made of built around 3 core components:

■ Rotating Machines■ Variable Speed Drives■ Process automation & control

We address 4 major markets:■ Marine■ Oil & Gas■ Energy (Mainly renewable)■ Industry

Our scope covers consulting, design, manufacturing, system integration, installation, commissioning and a broad range of services


History of HTS Development in Converteam

Rotating (and linear) electrical machines using HTS field windings. HTS coils with DC current working in medium strength magnetic fields (2-5 T)

■ 1999 – 2003■ Partner with American Superconductor (AMSC) in design study for

25 MW HTS motor for US Navy. Design, manufacture and test of 5 MW, 230 rpm motor.

■ 2004 – 2005■ Internal design and feasibility studies into the application of direct drive

HTS generators for wind power■ 2006 – present

■ Large scale projects involving the design and manufacture of HTS machines for renewable energy and marine propulsion.


Direct Drive HTS Wind Generator

Project Part Funded by TSB

■ Design of 8 – 10 MW, 11 - 12 rpm HTS generator■ Design uses 2G (YBCO coated conductor) HTS wire■ Airgap design – torque acts on HTS wire (6 – 8 MNm to be transferred

from cold to warm parts) and stator copper rather than iron cores■ Design, manufacture and test of a scaled prototype – 500 kW at

30 rpm■ Uses 1G (BiSCCO) due to availability (42 km of wire) at time of wire

purchase■ Similar construction to full size machine


HTS Model Wind Turbine Generator

The 8 MW, 12 rpm GeneratorThe 8 MW, 12 rpm Generator

5 m diameter, 2 m long, 100 tonnes5 m diameter, 2 m long, 100 tonnes


OPT Powerbuoy – HTS Linear Wave Generator

Rating: 150kW average, 1 MW peakDesign / Feasibility Study 2008-2009

Five full size torque links manufactured for mechanical testing - (approx. 600mm long x 100mm diameter at ends)

Stator

Cold Field System

Bearing Assembly


POSE2IDON

EU FP7 Funded Project, 4 years, €20m, 41 partners

■ Electric Ship Propulsion System■ HTS Generators incorporating power electronic providing DC output■ DC Distribution system■ HTS DC cable (Nexans)■ Zonal power supply units – DC to local AC■ HTS DC propulsion motors with integral power electronics■ Energy store to supply propulsion power for short periods■ Shore connection

■ Benefits■ Increased efficiency■ Zero emissions in and out of port■ More power dense motors and generators allowing electric propulsion

to be viable in smaller vessels■ Project includes design and build of demonstrator system


POSE2IDON Demonstrator HTS Generator + HTS Motor

Demonstrators designed and manufactured using 2G HTS wire

■ Demonstrator generators (2):■ 1.5 MW at 1500 rpm■ Cold iron in rotor■ Stator with laminated iron teeth and solid copper coils■ Optimum for smaller machines

■ Demonstrator motor (1)■ 2 MW at 200 rpm■ Airgap HTS rotor winding■ Airgap stator winding uing

litz wire■ Optimum for larger HTS

machines



EU FP6 Funded

■ 1.7 MW, 214 rpm hydro generator■ Design, manufacture, test and put into commercial service■ Conventional stator■ Rotor with HTS field winding and warm, iron poles■ 50 Hz machine directly connected to grid



Rating: 1789kVA, 1700 kW, 5250V, 28 poles, 0.95 pf, 214 rpm

Conventional stator (warm)Conventional stator (warm)

Eddy current shield (warm)Eddy current shield (warm)

Turbine couplingTurbine coupling(warm)(warm)

Exciter (warm)Exciter (warm)

Vacuum chamber (warm)Vacuum chamber (warm)

HTS Field Coils (cold)HTS Field Coils (cold)

Rotor (warm)Rotor (warm)

Rotating couplingRotating coupling(warm/cold)(warm/cold)

Torque linksTorque links(warm/cold)(warm/cold)

Horizontal shaft machine driven by a Francis double turbine withHorizontal shaft machine driven by a Francis double turbine with integral thrust bearing.integral thrust bearing.Back of core diameter = 3m, Axial length = 1mBack of core diameter = 3m, Axial length = 1m

Conventional stator (warm)Conventional stator (warm)

Eddy current shield (warm)Eddy current shield (warm)

Turbine couplingTurbine coupling(warm)(warm)

Exciter (warm)Exciter (warm)

Vacuum chamber (warm)Vacuum chamber (warm)

HTS Field Coils (cold)HTS Field Coils (cold)

Rotor (warm)Rotor (warm)

Rotating couplingRotating coupling(warm/cold)(warm/cold)

Torque linksTorque links(warm/cold)(warm/cold)

Horizontal shaft machine driven by a Francis double turbine withHorizontal shaft machine driven by a Francis double turbine with integral thrust bearing.integral thrust bearing.Back of core diameter = 3m, Axial length = 1mBack of core diameter = 3m, Axial length = 1m


Test results – June 2010Test results – June 2010

HYDROGENIEHigh Temperature Superconducting (HTS) Hydroelectric Generator

Rotor Cool Down Curves (Coil Nos. 1 to 28)

405060708090

100110120130140150160170180190200210220230240250260270280290300

Time

Tem

pera

ture

(K)

48 Kelvin (-225oC)Lowest coil temperature achieved

with just one cryocooler


Test results – June Test results – June

20102010

HYDROGENIEHigh Temperature Superconducting (HTS) Hydroelectric Generator

Rotor Resistance during Cool Down (Coil Nos. 1 to 28)

0

1

2

3

4

5

6

7

8

9

10

Time

Res

ista

nce

(ohm

s)

115 Kelvin (-158oC)HTS coil resistances start to drop

95 Kelvin (-178oC)All 28 HTS coils are superconducting

(Zero resistance!)


IET Innovation Award: Power / Energy 2009


Cryocoolers + coolantCryocoolers + coolant

High temperature superconductors can be cooled by liquid nitrogen (77K)

Practical electrical machines still require high temperature superconductors

to be cooled to much lower than liquid nitrogen temperature (say 25 to 40K)

– e.g. using cold helium gas

Commercially available cryo-coolers can be used for 25 - 40 K operation providing >100W cooling power

Lower temperatures mean higher cooling costs but less HTS wire

Cooling and coolant transferCooling and coolant transfer


Rotating couplingRotating coupling Usually takes the form of two concentric thin-walled tubes, one rotating inside the other. Seals used can be either PTFE or ferrofluid or a combination. Alignment, robustness and reliability are important.



High thermal conductivity materialsHigh thermal conductivity materials Choice of grades of copper with specific heat treatments and surface coatings to

enhance bonding and heat transfer. Allowance must be made for thermal differential contractions

between soldered or bolted materials.



Minimisation of heat loadsMinimisation of heat loads

Cryogenic Heat Load in a large HTS machine

Full Load Heat Budget

Internal Coil Heat Load, 6%

Conduction Heat Load, 46%

Radiation Heat Load, 48%


Maintenance of Vacuum LevelMaintenance of Vacuum Level Pumps Component cleanliness – remove oxidation, rust, grease, oils etc. Trapped volumes – e.g. at the bottom of ‘blind’ bolt holes, laminations Getters

Getter elementGetter element



Vapour Pressure of Common Gases

1.0E-11

1.0E-10

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1 10 100 1000

T, Temperature (K)

Pv, V

apou

r Pre

ssur

e (m

bar)

H2

D2

CH4

H2O

Ne

N2

CO

O2

Ar

CO2

Kr

Xe

TCTBAPv 1010 log.log +−= Using the Clausius-Clapeyron equation:

N2 at 30K and1 x 10-5 mbar

Feb 2008 21

Maintaining Vacuum LevelMaintaining Vacuum Level Cryopumping



Low thermal conductivity materials – glass fibre, carbon fibreLow thermal conductivity materials – glass fibre, carbon fibre For wind generator – Transmit 8 MNm of torque with just over 20 W of For wind generator – Transmit 8 MNm of torque with just over 20 W of

conduction heat loadconduction heat load

GRP thermal support linkGRP thermal support link Superinsulated GRP linkSuperinsulated GRP link


Carbon Fibre thermal torque linkCarbon Fibre thermal torque link


Multi-layer insulation (i.e. superinsulation)Multi-layer insulation (i.e. superinsulation) Aluminised Mylar and polyester Must provide sufficient overlap Must not over-compress Must not thermally short layers


Profile and thermally dump Profile and thermally dump current leads and wiringcurrent leads and wiring Use long lengths of conductor with profiled cross-sectional areas. Thermally dump to intercept conduction heat paths


Infrastructure RequirementsInfrastructure Requirements

Testing Facilities / Information DatabasesTesting Facilities / Information Databases Converteam designed and built its own development test facilities Warwick University and Cambridge University provided crucial support Daresbury, The Rutherford Appleton Laboratory and Suppliers helped with their expertise


Key enablers for HTS machines

Cost Reduction

■ Reduce the cost of HTS wire■ All chemical coated conductor manufacturing process■ Volume Production – chicken and egg as it requires a mass market for

HTS machines■ Reduce the cost of cryogenic and vacuum manufacturing

■ Components such as cryostats and large stainless steel structures■ Investigate use of lower cost materials not normally used in cryogenic

and vacuum enginnering


Key enablers for HTS machines

Industrialisation of cryocoolers Low maintenance or preferably maintenance-free Low susceptibility to vibration etc. Able to withstand high 'g' forces due to rotation – for rotor mounted coolers Higher efficiencies

Industrialisation of helium transfer rotating coupling Robustness is very important Long term reliability is required Reduced susceptibility to misalignment

Industrialisation of instrumentation and components e.g. high vacuum pressure gauges, valves, etc. capable of withstanding high 'g' forces due to rotation.

Industrialisation of high vacuum pumps i.e. capable of withstanding high 'g' forces due to rotation Low maintenance / maintenance-free

Supplier chain and test facilities Ideally local to project design and build Should use universities more


Thank you for your attention

www.converteam.com

http://www.converteam.com/

cryogenics day converteam - research councils uk

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