Testing of a Subscale HTS Coil for Wind Turbine Generator

Large-power direct-drive superconducting generators for offshore wind turbines show promise for competitive cost of energy and would enable the deployment of wind turbine outputting 10 MW or more. As part of an ARPA-e project, a 10-MW generator based on YBCO excitation coils was designed and optimized for a minimum cost of energy. The rotor is using an iron core in order to reduce the amount of HTS required leading to a potential competitive cost of energy. A subscale HTS coil was fabricated using off-the-shelf YBCO tapes as a proof of principle. This paper deals with the development of the testing rig for HTS coils at 30 K. The first coil tested is 0.65 m long and 0.32 m wide. It is composed of about 54 m of YBCO tape from Superpower Inc. The coil is conduction cooled using an AL325 cryocooler. The experimental setup is described in detailed, as well as the electromagnetic and thermal analysis of the coil. The experimental results consist in Ic measurements and voltage monitoring to identify potential conductor motion or mechanical structure degradation.