Slide 1

A short overview of superconductivity Dr. Jean Botti EADS Chief Technical Officer Tunisia, May 2012

Slide 2

Introduction about superconductivity

What is it? Below a critical temperature, some materials expel magnetic fields (Meissner effect) and have a zero electrical resistance. It is called superconductivity. Two types of superconductors: •  Low Temperature Superconductor (LTS) metals at < 30 K •  High Temperature Superconductor (HTS) ceramic materials at > 77K What does it allow? •  While using DC current, it allow a 100% efficient electricity transportation. It

is also possible to carry 10 times more current than a conventional cable.

•  Due to zero electrical resistance effect, superconductor can maintain a current with no applied voltage. It is used to create superconducting electromagnets.

Slide 3

Superconductor applications

EADS VoltAir

TRL 9 0 3 6

-  MRI -  Mass

spectrometers -  Particle

accelerators

-  HTS machine for submarines propulsion

-  Electric power transportation in power grid

-  HTS machine for aeronautic

Sumitomo & IHI pod propulsion system with HTS motor (400kW)

World's first HTS power transmission cable system installed in Long Island Power Authority’s (LIPA)

Tevatron MRI

NASA N3-X concept

Slide 4

Superconductor current applications •  Highly efficient and compact electric motors (expected to reach 30 kW/kg and more

than 99% efficiency(1))

Example for a ship propulsion motor (2)

Superconductor potential use in aeronautic •  For a future electrically powered aircraft, superconductivity can be used for:

•  High efficiency and power density cables •  High efficiency and power density electric motor

Superconductor applications

Slide 5

Superconductor current applications •  Highly efficient and compact electric motors (expected to reach 30 kW/kg and more

than 99% efficiency(1))

Example for a ship propulsion motor (2)

Superconductor potential use in aeronautic •  For a future electrically powered aircraft, superconductivity can be used for:

•  High efficiency and power density cables •  High efficiency and power density electric motor

Superconductor applications

Slide 6

Superconductor potential use in aeronautic: comparison with conventional technology

Copper cable (20kA)

HTS cable (20kA)

Weight (kg/m) 80 4

Volume (l/m) 7 0.7

Heat loss (W/m) 1000 10

Comparison of HTS (current technology) and conventional cable for a 5 MW cable at 270 VDC (2)

HTS vs conventional Cable

Conventional motor

HTS motor (targeted performances(2))

Gravimetric power (kW/kg) 5 30

Volume (kW/l) 15 50

Efficiency (%) 96% >99%

Comparison of conventional electric motor with expected performances of HTS motor

HTS Motor vs conventional

Slide 7

Challenges regarding superconductivity

•  Cryocooling requirement: superconductors need to cool down to below 70K

•  Sensitive to temperature, current density and magnetic field. If one of them overcomes its critical value somewhere in the superconductor, a quench occurs: it is when the superconductor enters the normal (resistive) state. It can heavily irreversible damage the superconductor. A good monitoring is required.

•  Ceramic materials (used for High Temperature Superconductor) are difficult to manufacture into wires or strips and are very expensive.

Slide 8

Superconducting technology pros & cons

Pros •  Power density

•  High efficiency (over 99% for electric motors)

•  Compact design suitable for aircraft integration

•  Enable high electric power (~MW) for airborn use

Cons •  Cooling constraints

•  Need to monitor current and magnetic field (avoid quench)

•  Manufacturing problems of HTS ceramic wires

•  Not currently mature for aeronautic

Slide 9

In conclusion

•  Superconductivity will remain a viable technology because of its density and high efficiency – among other reasons

•  In the future, the applications of superconductivity science will increase, not decrease

•  The applications of superconductivity do and will benefit both the civil and defence domains thereby, it increases the opportunities to improve the application of this technology

•  International cooperation concerning the application of this technology should be increased

Slide 10

APPENDIX: For J. Botti Reading

Formation - Moteurs et Turbomachines aéronautiques

Slide 11

Study on HTS machines for aircraft use Summary:

•  State-of-the-art of existing and under development HTS machines

•  Paper study of the design of two types of HTS synchronous machines for aircraft use

•  Study will be done by GREEN lab •  Partner: Hispano-Suiza

ANR TDM SUPREME PROPOSAL Summary:

•  TDM: ANR program dedicated to research on elementary components in transportation industry

•  Detailed study of a 600 kW HTS machine for aeronautic application

•  Prototyping of a smaller version of the HTS machine (60 kW)

•  Partners: GREEN, Hispano Suiza and Absolut Systems

HTS activities and related projects in IW TCC6 (1/2)

Oswald Tech Watch

To Be Completed By Peter

Slide 12

Rolls-Royce study Summary:

•  Study cryocooling in hybrid propulsive architecture

•  Topics investigated: sizing, design, requirements, constraints

•  HTS motor and wire technology knowledge required for cryocooling system sizing

GaTech fellowship Summary:

•  Fellowship between EADS IW and GaTech

•  Study performances of two disruptive propulsive architectures: Hybrid Series turbogenerator and SOFC-GT architectures

•  HTS motor model given by the NASA Glenn Research Center used

•  Model created by P. Masson and used for NASA N+3 study SUGAR.

eCraft study with Airbus Summary:

•  Study the long-term potential and opportunities of electricity as an alternative major onboard energy source for propulsion

•  HTS technology under study for HTS wire and HTS machines

•  HTS machines & HTS wire modeled

HTS activities and related projects in IW TCC6 (1/2)