Experience in manufacturing a large HTS magnet for a SMES

Transcription

1 Superconducting magnets April 05-09, 2009 CEA Cadarache, France Experience in manufacturing a large HTS magnet for a SMES P. Tixador Grenoble INP / Institut Néel - G2Elab

2 Outline Introduction: SMES SMES: performances & limits DGA / CNRS / Nexans project Application Conductor, magnet, cryogenics Tests Conclusions Project phase II 2 P. Tixador, Grenoble INP

3 Energy storage in a coil coil L, R I.C.: t = 0 ; I = I o " I = I o e # t % $ $ = L ( ' * & R) W = 1 2 LI 2 = W o e "2t # R = 0 => τ infinite => energy stored and available Rare mean of electricity direct energy storage Superconductors indispensable Device : SMES (Superconducting Magnetic Energy Storage) 3 P. Tixador, Grenoble INP

4 SMES: dual of capacitor Storage Discharge Source SMES I 1 2 L I 2 I Current Capacitor 1 2 C V 2 V V Voltage 4 P. Tixador, Grenoble INP

5 First SC device in a grid P max f W max W exch I o - V o Ø magnet 10 MW 0.35 Hz 30 MJ 9.1 MJ 5 ka kv 2.7 m BPA SMES on the grid installed in 1979 (transmission stabilization, low frequency power oscillation damping) One year operation. Cryogenic problems and other solution to damp the oscillations. 5 P. Tixador, Grenoble INP

6 Superconducting magnets April 05-09, 2009 CEA Cadarache, France SMES Performances Limits

7 Energy and power densities Mass specific power (kw/kg) ,1 0,01 0,001 Dielectric capacitors Super capacitors SMES Batteries Batteries 0,01 0, Mass specific energy (Wh/kg) Ragone chart: Performance comparison of storing devices 7 P. Tixador, Grenoble INP

8 SMES application Mass specific power (kw/kg) ,1 0,01 Dielectric capacitors Super capacitors SMES Batteries Batteries 0,001 0,01 0, Mass specific energy (Wh/kg) Discharging time Hours Minutes Metal-air Flow batteries batteries High energy NaS batteries supercaps Lead-acid batteries Long dura. flywh. Ni-Cd batteries Li-ion batteries High power flywheels Pumped hydro CAES Seconds High power supercaps SMES 1 kw 100 kw Power 100 MW 8 P. Tixador, Grenoble INP

9 Energy & power limits Energy Magnetic flux density W Vol " 1 2 B 2 µ o Mechanical stresses W Mass " # d (Viriel th) [" = J B R (solenoid)] Metallic structure with 100 MPa: 12.5 kj/kg (3.5 Wh/kg) Metallic structure limit: kj/kg (present: 14 kj/kg) Composite structure limit (theoretical): 150 kj/kg Mechanics: very important for SMES 9 P. Tixador, Grenoble INP

10 Energy & power limits Power (VI) Voltage & current Good electric isolation He gas bad dielectrics High current conductor Eddy current losses Cryostat Conductor (coupling losses) Mass specific power (kw/kg) ,1 0,01 Dielectric capacitors Supercapacitors SMES Batteries 0,001 0,01 0, Mass specific energy (Wh/kg) 10 P. Tixador, Grenoble INP

11 HTS SMES Cooling power (W) AL K C p (J/cm 3 /K) 1 0,1 0,01 0,001 4 K : 1 20 K : 75 Cu 50 K : 900 I c (A/cm-w) CC - 20 K 1000 PIT - 20 K PIT - 50 K CC - 50 K 100 CC - 77 K PIT - 77 K Cold temperature (K) 0, Temperature (K) Magnetic flux density (T) " c = 250 MPa (PIT ) " c = 700 MPa (CC) Cryogenic cost running investment Stability margins & perturbations Isolating thickness voltage => power (VI) Interest HTS & CC 11 P. Tixador, Grenoble INP

12 Summary: SMES advantages High power density & large energy density Quick response time Number of charge-discharge cycle very high (infinite) Static system / low maintenance Specific application of superconductivity Conversion efficiency may be high (> 97 %) 12 P. Tixador, Grenoble INP

13 Superconducting magnets April 05-09, 2009 CEA Cadarache, France DGA / CNRS / Nexans project

14 HTS 800 kj SMES SMES potentialities for military uses High power pulse sources (electric weapons) DGA-Nexans-CRTBT project Progress in Bi-2212 tape & conductor Development basic HTS SMES technologies Design, realization and test of a SMES K T d = 2 s (& 10 ms) User friendly cryogenics 14 P. Tixador, Grenoble INP

15 SMES for pulsed power source SC magnet Switch L O A D Primary source Control 15 P. Tixador, Grenoble INP

16 SMES conductor - PIT Bi-2212 tape 0.26 x 4.11 mm 2 Nexans Reference curve for the design 50 % higher values measured Critical current (A) Filaments, Ag matrix External shealth AgMg σ (95 % I c ) 100 MPa T = 20 K B tr B lg B B tr lg Magnetic flux density (T) Engineering current density (MA/m 2 ) 16 P. Tixador, Grenoble INP

17 Bi-2212 PIT Conductor Multi tape soldered conductor Stability: possible current redistribution Adaptation to B, θ et σ: tape number, reinforcement => Superconductor use optimization Conductor with SS tape for mechanical reinforcement Mechanical improvement σ c (95 % I c ) 170 MPa (100 MPa (tape)) No transposition: «big» single tape behaviour (AC losses x 4 in B lg ) 17 P. Tixador, Grenoble INP

18 SMES magnet Energy Diameter int./ext. Height Rated current Operating temperature 814 kj 300 / 814 mm 222 mm 315 A 20 K Pancakes: SMES characteristics No layer jump (no transv. def.) 26 pancakes Flat solenoid optimizes SC vol. B z = 5.25 T; B r = 2.5 T Easy to change the conductor σ θ = 80 MPa (100 MPa) Conduction cooling simple σ z = 24 MPa BUT internal connection 18 P. Tixador, Grenoble INP

19 SMES magnet 4 tape conductor 3 tapes R = tapes + SS conductor Critical current (A) T = 20 K B tr B lg B B tr lg Magnetic flux density (T) Engineering current density (MA/m 2 ) 19 P. Tixador, Grenoble INP

20 SMES magnet 4 tape conductor 3 tapes R = tapes + SS conductor Hoop stress (MPa) Pancakes 13-14!' (MPa) "! (MPa) " Radius (mm) Independent turn Dependent turns 20 P. Tixador, Grenoble INP

21 Specifications: Cryogenics Coil temperature: 20 K Invisible cryogenics, no cryogenic fluid Conduction cooling from cryocoolers Reliable and high performances No cryogenic skills «plug & play» Careful design 21 P. Tixador, Grenoble INP

22 Cooling Kapton 110 W/m 2 /K (20 K) HTS conductor Adhesive epoxy film bonding Insulation epoxy Copper plate 22 P. Tixador, Grenoble INP

23 Magnet Ø i = 300 mm Ø e = 814 mm 23 P. Tixador, Grenoble INP

24 HTS SMES From CAD drawing to reality 24 P. Tixador, Grenoble INP

25 HTS SMES 25 P. Tixador, Grenoble INP

26 Cooling down Thermal shield Magnet cryoccoler Pancake wing 0:00:00:00 1:00:00:00 2:00:00:00 3:00:00:00 4:00:00:00 5:00:00:00 6:00:00:00 7:00:00:00 Times (day) Shield cryocooler: 15.8 K (20 W) Lowest temperatures (I = 0): 2 brass CL + radiation + conduction Magnet cryocooler: 11.7 K (3 W) 2 HTS CL + conduction + radiation 26 P. Tixador, Grenoble INP

27 Resistive discharge 1/2 24 pancake magnet Current (A) Time (s) Voltage (V) Power (kw) Time (s) Energy (kj) P max = 175 kw & W max = 425 kj 27 P. Tixador, Grenoble INP

28 Resistive discharge 2/ Current (A) 250 Under pancake Upper pancake Time (s) Temperatures (K) About 1000 s (15 min) to recover the initial temperatures Wing temperatures 28 P. Tixador, Grenoble INP

29 Capacitor discharge 800 Current (A) Voltages (V) Time (ms) Measurement Sinus Time (ms) => Low AC losses 29 P. Tixador, Grenoble INP

30 Conclusions Complete design & realization of a HTS SMES PIT Bi-2212 pancakes Conduction cooling Successful cooling down Thermal system worked globally as designed 245 A (78 % rated); 425 kj; 175 kw Low AC losses A problem on one pancake 30 P. Tixador, Grenoble INP