Superconducting Generators for Large Wind Turbines Ozan Keysan Institute for Energy Systems The University of Edinburgh 26/09/2012

Motivation BARD 5MW Global Offshore Wind Energy Markets and Strategies,2009 In 2020, 85% of offshore wind turbine installations will be larger than 5 MW

Wind Turbines: Constantly Growing  How big?  UpWind Project: A 20 MW Wind Turbine is Feasible

Superconducting Machines Courtesy of Siemens, Converteam (ALSTOM)  Siemens: 400 kW  Converteam (ALSTOM): 5 MW HTS

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

Mass of Direct-Drive Generators Harakosan 1.5MW,18 rpm,47 tonnes (*) D. Bang et.al. “Review of Generator Systems for Direct-Drive Wind Turbines,” 2008, All data available at goo.gl/ZZivv goo.gl/ZZivv Enercon 4.5 MW, 13 rpm 220 tonnes

All data available at goo.gl/ZZivv goo.gl/ZZivv Mass of Direct-Drive Generators

Reliability of Wind Turbines Hahn, B., & Durstewitz, M. (2007). Wind Energy-Reliability of Wind Turbines. ~1MW, 1500 onshore turbines

Reliability?  Cooling System  Cryogenic Couplers  Electric Brushes  Transient torques on SC  Demagnetization for Bulk SC  AC losses on SC wire Issues with Superconducting Generators SeaTitan AMSC, 10 MW, 10 rpm Direct-drive superconducting generator

Transverse Flux HTSG

 Pros  Single Stationary SC Coil  No Brushes  No Cryogenic Coupler  Bidirectional flux  High Torque Density  Cons  Magnetic Attraction Forces  3D Flux (Soft magnetic composites needed) Transverse Flux HTSG

Linear Prototype

Some Photos & A Short Video

Next Stage  A Superconducting Field Winding  Simple Insulation  LN2 bath  Design for Large Wind Turbine  10 MW 10 rpm  Mass/Cost Estimation

THANKS