EPRI SCDC Cable Review Meeting Palo Alto 24
EPRI SCDC Cable Review Meeting Palo Alto 24 th October 2006 • Meeting May 22 -26 th Sevenoaks UK • Progress since
Sevenoaks Meeting: 22 -26 th May 2006 • Agreed cable types: – 2 x monopoles – 100% redundancy • Agreed target ratings: – 10 GW (2 x 10 GW) – 2 GW (2 x 1 GW) • Developed cable design spread sheet – Add BSCCO PIT characteristic: I, H, T • Actions: (See Bill’s slides) – Method to determine Magnetic field and PIT current/wire at outer surface of inner conductor – Circulate spreadsheet – In parallel prepare vacuum and cryogenic info to add – In parallel to add cable losses – In parallel to add circuit parameters
Progress Since May • Spread sheet: – Added magnetic field and PIT current/wire at outer surface of inner conductor – Circulated Spreadsheet and ‘instructions’ • Patent proposals submitted to EPRI: ‘contraction compensation’ • Produced draft DC cable ‘design primer’ • Performed preliminary sensitivity study to identify limiting boundaries (to present later) • Performed outline search for extrudable insulation materials
DC Cable Configuration
Bi-Pole’s Advantages: Simplest Construction, Half-Insulation Thickness and Smaller Diameter and Longer Cable Conventional Bi-Pole Designs are Unsuitable • No ground return, so lose one cable, lose circuit. • Mutual magnetic field is perpendicular to PIT conductor • Ground conductor is added to give N+1 security • No outer HTSC shield: field is not contained • Mutual magnetic field is perpendicular to PIT conductors
Selected Design: Two Monopoles Ground Returns Must be Current Carriers Integrated HTSC Ground return conductor +ve pole -ve pole Integrated HTSC Ground return conductor • Half insulation thickness of one monopole • One third insulation thickness of a single integrated bi-pole • Ground conductors are added to give N+1 security • Concentric HTSC conductor: field is parallel to PIT: OK • No mutual magnetic field Does this cause problems to the bridge design and control? Opposite or same polarity poles?
DC Cable Sensitivity Study: Boundary Limitations • Dry cable construction, extruded insulation, can be factory HV tested, joints are simplest. • Voltage and current: no restriction • Fault circuit current: 2 x rated current for 1 sec and 1 K rise • Maximum number of tapes in one pass on present stranding machines is 150. Perhaps extend to 250? (Need to ask manufacturers). See video of cable factory. • Reel: – – outer diameter: 4. 2 m hub diameter: 20 D (D is cable OD) Width: 2. 4 m (could increase) Cable net weight: 30 ton (could increase). • Installation: See video of cable factory – Tensile load: F=COF x Unit Mass x Length – Maximum safe load on cable= 50 N/mm 2 of stranded conductor area. • PIT tape: – Present BSCCO minimum bend diameter: 70 mm – Will tape width conform to circumference?
Present Spread Sheet Limits for 75 mm OD Conductor Show: • We need more tapes than present strander machine limit of 150 tapes • Optimum voltage is ~100 -120 k. V
For 75 mm OD Conductor: • 1 GW rating is OK • 2 GW: too many tapes needed
No Duct Case: • 1 GW Cable is OK at 70 k. V and above with <150 tapes • Optimum voltage for min OD is 120 k. V • Max cable length on reel is 6. 2 k. M, but reel weight is high at 38. 4 t Power pole GW 1. 00 1. 00 Current A 20, 000 16, 666 14, 280 12, 500 11, 111 10, 000 8, 333 6, 666 5, 000 Pole voltage k. V 50 60 70 80 90 100 120 150 200 Duct internal diameter (target) mm 0. 00 0. 14 0. 86 0. 33 0. 41 0. 37 0. 78 0. 76 0. 41 Area inner quench conductor mm 2 544 454 389 340 302 272 227 181 136 Conductor OD (entered into sheet) mm 30. 90 28. 20 26. 10 24. 60 23. 00 22. 00 20. 05 18. 30 15. 80 Max current per tape inner conductor A 93 95 97 99 100 101 103 106 108 Number of PIT wires-inner conductor Number 197 162 133 124 103 97 76 69 49 Number of PIT layers inner conductor Number 10 9 8 8 7 7 6 6 5 mm 1. 95 2. 34 2. 74 3. 15 3. 58 4. 03 5. 01 6. 63 10. 03 Number of PIT wires outer conductor Number 185 177 142 111 109 81 84 62 Number of PIT layers outer conductor Number 6 6 5 4 4 4 3 3 2 Cable outer diameter mm 62. 88 59. 88 57. 36 55. 59 54. 31 53. 69 52. 49 53. 04 55. 88 Cable unit weight kg/m 13. 33 11. 40 9. 82 8. 67 7. 28 6. 20 5. 49 4. 71 Cable weight on reel T 54, 751 53, 550 48, 158 44, 821 42, 996 42, 730 38, 377 31, 828 24, 489 Cable length on reel m 4, 107 4, 696 4, 906 5, 172 5, 482 5, 866 6, 192 5, 795 5, 199 Insulation thickness 7. 84
20 mm Duct Case: • 1 GW Cable is OK at 70 k. V and above with <150 tapes • Optimum voltage for min OD is 120 -150 k. V • Max cable length on reel is 4. 4 k. M, but reel weight is OK at 27 -32 t Power pole GW 1. 00 1. 00 Current A 20, 000 16, 666 14, 280 12, 500 11, 111 10, 000 8, 333 6, 666 5, 000 Pole voltage k. V 50 60 70 80 90 100 120 150 200 Duct internal diameter (target) mm 20. 03 20. 22 20. 08 20. 38 20. 09 20. 01 20. 11 20. 09 Area inner quench conductor mm 2 544 454 389 340 302 272 227 181 136 Conductor OD (entered into sheet) mm 38. 50 36. 50 34. 70 33. 50 32. 50 31. 80 30. 45 28. 90 27. 90 Max current per tape inner conductor A 98 101 103 105 107 108 110 112 115 Number of PIT wires-inner conductor Numb er 202 168 137 112 108 105 81 58 56 Number of PIT layers inner conductor Numb er 8 7 6 5 5 5 4 3 3 mm 1. 94 2. 31 2. 69 3. 07 3. 47 3. 88 4. 73 6. 09 8. 57 Number of PIT wires outer conductor Numb er 180 175 137 135 101 102 69 75 Number of PIT layers outer conductor Numb er 5 5 4 4 3 3 3 2 2 Cable outer diameter mm 69. 00 66. 68 64. 45 63. 38 62. 24 61. 90 61. 54 61. 55 64. 69 Cable unit weight kg/m Insulation thickness 14. 06 12. 19 10. 55 9. 54 8. 62 8. 09 7. 21 6. 15 5. 72 Cable weight on reel kg 46, 919 43, 607 41, 739 39, 476 36, 194 33, 805 31, 799 27, 147 21, 942 Cable length on reel m 3, 336 3, 578 3, 955 4, 139 4, 201 4, 177 4, 411 4, 412 3, 837
40 mm Duct Case: • 1 GW Cable is OK at 70 k. V and above with <150 tapes • Optimum voltage for min OD is 100 -120 k. V • Max cable length on reel is 2. 8 k. M and reel weight is OK at 22 -25 t Power pole GW 1. 0 1. 0 Current A 20000. 0 16666. 0 14280. 0 12500. 0 11111. 0 10000. 0 8333. 0 6666. 0 5000. 0 Pole voltage k. V 50. 0 60. 0 70. 0 80. 0 90. 0 100. 0 120. 0 150. 0 200. 0 Duct internal diameter (target) mm 40. 2 40. 0 40. 1 40. 0 40. 3 40. 0 40. 1 Area inner quench conductor mm 2 544. 5 453. 7 388. 8 340. 3 302. 5 272. 2 226. 9 181. 5 136. 1 Conductor OD (entered into sheet) mm 52. 8 51. 5 50. 2 49. 6 48. 5 47. 6 46. 5 45. 9 Max current per tape inner conductor A 104. 9 107. 6 109. 6 111. 3 112. 5 113. 6 115. 3 117. 0 118. 9 Number of PIT wires-inner conductor Number 179. 0 175. 0 137. 0 135. 0 99. 0 97. 0 64. 0 63. 0 Number of PIT layers inner conductor Number 5. 0 4. 0 3. 0 2. 0 mm 1. 9 2. 3 2. 6 3. 0 3. 4 3. 8 4. 5 5. 7 7. 9 Number of PIT wires outer conductor Number 183. 0 182. 0 135. 0 134. 0 90. 0 91. 0 93. 0 49. 0 Number of PIT layers outer conductor Number 4. 0 3. 0 2. 0 1. 0 Cable outer diameter mm 81. 4 79. 9 78. 2 77. 8 77. 1 76. 9 77. 0 77. 8 80. 4 Cable unit weight kg/m 14. 8 13. 2 11. 5 10. 6 9. 8 9. 0 8. 3 7. 5 6. 7 Cable weight on reel kg 33503. 8 33320. 8 28375. 4 28440. 2 25841. 8 24720. 3 21925. 1 18362. 6 16449. 6 Cable length on reel m 2264. 3 2528. 9 2475. 9 2673. 4 2650. 3 2753. 9 2648. 7 2463. 4 2440. 4 Insulation thickness
1 GW with no central duct: Optimum voltage is 120 k. V
Minimum voltage is 70 k. V, OK for <150 wires
At optimum 120 k. V only need 76 wires, so can double current and power to 2 GW?
1 GW Study Conclusions: To achieve 5 GW need: 5 x Increase in current per tape, or a very long factory strander, or a multipass application?
1 GW: Unit weight falls with voltage
1 GW with no central duct: very long length is possible
120 k. V Constant Voltage and Increment Current and Power with BSCCO 125 A: • At 150 tape limit can achieve 1. 8 GW • At 316 tape limit can achieve 3. 6 GW • At 450 tape limit can achieve 5 GW Duct ID 0 mm • At 5 GW, reel length falls to 2 km • At 5 GW, reel weight is high at 56. 5 t 120 k. V Power pole GW 1. 00 Current (A) A Pole voltage (k. V) 300 -Tapes Increase Current 1. 20 1. 80 2. 40 3. 00 3. 60 4. 20 4. 80 5. 40 8, 330 10, 000 15, 000 20, 000 25, 000 30, 000 35, 000 40, 000 45, 000 k. V 120 120 120 Duct internal diameter (target) mm 0. 55 0. 37 0. 30 0. 00 1. 50 0. 88 0. 82 0. 50 0. 61 Area inner quench conductor mm 2 227 272 408 544 681 817 953 1, 089 1, 225 Conductor OD (entered into sheet) mm 20. 00 22. 00 27. 00 30. 90 34. 62 38. 20 41. 20 44. 00 46. 70 Max current per tape inner conductor A 103 101 97 93 90 87 84 82 80 Number of PIT wires-inner conductor Number 75 97 153 197 244 316 368 421 478 Number of PIT layers inner conductor Number 6 7 9 10 11 13 14 15 16 Insulation thickness mm 5. 01 4. 93 4. 80 4. 72 4. 67 4. 62 4. 59 4. 57 4. 54 Number of PIT wires outer conductor Number 81 114 159 208 261 320 336 396 462 Number of PIT layers outer conductor Number 3 4 5 6 7 8 8 9 10 Cable outer diameter mm 52. 44 55. 30 62. 04 67. 62 72. 86 77. 85 81. 87 86. 00 89. 97 Cable unit weight kg/m 6. 18 7. 43 10. 69 13. 87 17. 14 20. 57 23. 55 26. 83 30. 19 Cable weight on reel T 38, 246 39, 329 44, 775 50, 325 50, 302 50, 702 53, 628 55, 979 56, 995 Cable length on reel m 6, 187 5, 296 4, 187 3, 628 2, 934 2, 465 2, 278 2, 086 1, 888 Rings on reel Number 37 35 31 28 26 24 23 22 21 Flakes on reel Number 29 26 22 20 17 15 14 13 12 Reel hub OD mm 1049 1106 1241 1352 1457 1557 1637 1720 1799 Reel external width m 2. 4 2. 4 Reel Flange OD m 4. 2 4. 2
- Slides: 19