High-Temperature Superconducting Generators for Direct Drive Applications OZAN KEYSAN Institute for Energy Systems The University of Edinburgh April 2011

Ozan KEYSAN 2 Superconductor?  Abolish the OHM’s Law Kakani2009 Zero Resistivity

Ozan KEYSAN 3 MERCURY  The First Superconductor Material  Discovered in 1911  Critical Temp = 4.2 K (-269 C)

Ozan KEYSAN 4 Infinite Current? Unfortunately NOT.

Ozan KEYSAN 5 YBCO (YBa 2 Cu 3 O 7 ) Current Density > 200 A/mm2 (5-10 A/mm2 for copper)

Ozan KEYSAN 6 Perfect Diamagnetism

Ozan KEYSAN 7 Applications: MagLev Train

Ozan KEYSAN 8 Applications: Large Hadron Collider  Superconducting Magnets Up to 16 T, Normal PM ~1.5 T

Ozan KEYSAN 9 Applications: MRI

Ozan KEYSAN 10 Power Applications Courtesy AMSC, InnoPower Superconductor  Transmission Lines  Fault Current Limiter

Ozan KEYSAN 11 Power Applications : Electrical Machines Courtesy of Siemens, Converteam (ALSTOM)  Siemens: 400 kW  Converteam (ALSTOM): 5 MW HTS

Ozan KEYSAN 12 Power Applications : Electrical Machines  36.5 MW, 120 rpm (U.S. Navy, AMSC) Courtesy of AMSC

Ozan KEYSAN 13 Wind Turbine Applications? M. Lesser, J. Müller, “Superconductor Technology – Generating the Future of Offshore Wind Power,” BARD 5MW

Ozan KEYSAN 14 Direct-Drive Solutions EESM: Electrically excited Synchronous Machine HTSG: High-Temperature Superconducting Generator PMG: Permanent-Magnet Generator Bubble Size: Power Rating

Ozan KEYSAN 15 Cost Comparison (HTSG vs. PMG) Lesser2009

Ozan KEYSAN 16 Types of HTS Machines  Rotating DC Superconducting Field  Most Common Type  Transient Torques on HTS wire  Cryocooler Coupler + Brushes  Low Reliability  Cooling Times  Magnetized Bulk HTS  Very Difficult to Handle  Demagnetization  All Superconducting Machines  AC Losses on HTS wire

Ozan KEYSAN 17 Reliability?  Stationary SC Coil  No Cryogenic Coupler  No Brushes  No Transient Torque on SC  Simplified Cooling, Isolation  DC Field  No AC losses  Maximized Current

Ozan KEYSAN 18 Homopolar HTSG

Ozan KEYSAN 19 Homopolar HTSG

Ozan KEYSAN 20 Axial Bipolar HTS Machine

Ozan KEYSAN 21 Bonus: Bipolar Linear HTSG  Suitable for WECs

Ozan KEYSAN 22 Transversal Flux HTSG

Ozan KEYSAN 23 Thanks. OZAN KEYSAN