A Novel HTS Wind Generator Having Permanent Magnets Between the Rotor Pole-Tips

Superconducting direct-drive wind generators have been proposed as a possible approach for offshore wind energy application due to their inherent high torque density and small mass compared with conventional electrical machine. In this paper, a novel 10 MW high temperature superconducting (HTS) salient pole synchronous wind generator with additional permanent magnets inserted between the rotor silent pole-tips is proposed. First, the electromagnetic structure of this new topology is designed in detail and the performance improvements of this machine are investigated by finite-element analysis. These two kinds of assist effect are also clarified. Then, the proposed structure is compared with conventional HTS wind generator without assistant magnets under the same scale constraints. The comparison results show that with the accessorial magnets, the torque density can be increased by 22%. Finally, the symmetrical three-phase short-circuit fault performances of the proposed HTS machine are conducted to verify the generator reliability.