frankfurt (germany), 6-9 june 2011 alex geschiere liandon member of alliander alex geschiere –...
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Frankfurt (Germany), 6-9 June 2011
Alex GeschiereLiandon member of Alliander
Alex Geschiere – Netherlands – Session 1 – 1256
Superconducting cablesA breakthrough in development
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Triax cable
CryostatFormer
Phase 2 HTS Phase 3 HTS
Dielectric Dielectric Dielectric
Phase 1 HTS Copper Neutral
LN
LN
CryostatFormerFormer
Phase 2 HTSPhase 2 HTS Phase 3 HTSPhase 3 HTS
Dielectric Dielectric DielectricDielectricDielectric DielectricDielectric DielectricDielectric
Phase 1 HTSPhase 1 HTS Copper NeutralCopper Neutral
LNLN
LNLN
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Cryostat design
Stainless steel inner tube
Vacuum insulation with multy layer insulation (MLI)
Stainless steel outer tube
Vacuum: sealed for life. Residual gasses will be absorbed by getter material
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Smart electrical behaviour
very low Z
high Z
very low Z
high Z
very low Z
high Z
Low impedance during normal operation
Low energy losses and
Low impedance
Low energy lossesStable voltage profile
High impedance at increasing current
Limiting of short circuit
High impedance
Limiting of short circuit currents
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Temperature profile
L [m]
T [
K]
Go
Return
Tmax
Challenge:
Limit the difference between maximum and minimum temperature in long length cables
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Challenge Fault Current Limiting
High impedance at increasing current
Limiting of short circuit
high Z
High impedance
Limiting of short circuit currents
Challenge:
Resistive limiting will cause a significant amount of additional heat. Optimize heat management during faults.
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Breakthrough in cryostat design
Heat leakage from 1.5 W/m to 0.5 W/m
Reduced heat leakage in cryostat:- optimize MLI and spacers- mix of straight/rigid sections and corrugated/flexible sections
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Low friction design
Low friction of Nitrogen mass flow
Test of a 45 m low friction cryostat. A mass flow of 0.3 kg/s resulted in a pressure drop of only 5 mbar.
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Reduced AC losses
AC losses from 1.5 W/m/phase to 0.2 W/m/phase at 3000 Amps
•Reduction of gaps between tapes
•Narrow HTS tapes will fit the conductor shape better
•Special low loss 2G-tapes
Frankfurt (Germany), 6-9 June 2011
Alex Geschiere – Netherlands – Session 1 – Paper 1256
Test of reduced AC losses
Result form test: AC losses at 3000 Amps of 0.11 W/m/phase (goal 0.2 W/m/phase)
Test of three different constructions/tape designs. Huge impact on AC losses.
Frankfurt (Germany), 6-9 June 2011
Significant improvement in development of HTS cables possible in a two years development program.
Results are proved by several tests.
Alex Geschiere – Netherlands – Session 1 – Paper 1256