A Full-Size High-Temperature Superconducting Coil Employed in a Wind Turbine Generator Setup

A full-size stationary experimental setup, which is a pole pair segment of a 2 MW high-temperature superconducting (HTS) wind turbine generator, has been built and tested under the HTS-GEN project in Denmark. The performance of the HTS coil is crucial to the setup, and further to the development of the full generator. This paper deals with the HTS coil employed in the setup. The coil utilizing YBCO tapes is double-layered with 152 turns per layer and is wound on an FeNi9 iron core. Several sensors are installed to monitor the operating status of the coil, e.g., temperature, field, and voltage. The coil is tested in LN2 first, and then tested in the setup so that the magnetic environment in a real generator is reflected. The experimental results are reported, followed by a finite-element simulation and a discussion on the deviation of the results. The tested and estimated I-c in LN2 are 148A and 143 A, respectively. When tested in the setup, the maximum temperature of the coil is controlled at 77 K and 40 K, and the I-V curves under both conditions are presented. It is found that the lower half coil that is closer to the stator has a smaller I-c due to a higher field level. The study is of significance to the development of HTS generators.