Superconducting generators for renewable energy applications

There is a trend toward higher power rated machines for offshore wind turbines. The maximum power rating for a high-speed, geared power-takeoff system is around 5MW. For even higher power rated turbines, direct-drive generators becomes enormously heavy. Direct-drive superconducting generators have the potential to reduce the overall mass and installation costs of an offshore wind turbine. In this study, a conventional homopolar superconducting generator design is presented that is suitable for low-speed, high-torque direct-drive applications. The generator has been designed with a stationary dc-field winding to increase the reliability of the generator. Also, a linear version of the generator is presented.