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

Ozan KEYSAN 2 Power Applications Courtesy AMSC, InnoPower Superconductor  Transmission Lines  Fault Current Limiter

Ozan KEYSAN 3 Power Applications : Electrical Machines Courtesy of Siemens, Converteam (ALSTOM)  Siemens: 400 kW  Converteam (ALSTOM): 5 MW HTS

Ozan KEYSAN 4 Power Applications : Electrical Machines  36.5 MW, 120 rpm (U.S. Navy, AMSC) Courtesy of AMSC

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

Ozan KEYSAN 6 Direct-Drive Solutions

Ozan KEYSAN 7 Cost Comparison (HTSG vs. PMG) Lesser2009

Ozan KEYSAN 8 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 9 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 10 Homopolar HTSG

Ozan KEYSAN 11 Homopolar HTSG

Ozan KEYSAN 12 Axial Bipolar HTS Machine

Ozan KEYSAN 13 Bonus: Bipolar Linear HTSG  Suitable for WECs

Ozan KEYSAN 14 Transversal Flux HTSG

Ozan KEYSAN 15 Prototype  < 1m Diameter  250 rpm  5 kW

Ozan KEYSAN 16 SC Winding – Cryocooler  Inner Diameter:300mm  Outer Diameter:400mm  125m YBCO Wire (0.1x12 mm)  Excited with DC Source  Liquid Nitrogen Cooled (maybe Neon)  Similar cooling system to homopolar HTS motors. T. Zhang, K.Haran, E.T. Laskaris,J.W. Bray, “Design and Test of a Simplified and Reliable Cooling System for High Speed Superconducting Generator Applications,”