Electromagnetic Characteristic Analysis and Optimization Design of a Novel HTS Coreless Induction Motor For High-Speed Operation

We develop a novel high-temperature superconducting (HTS) induction motor with saddle-shaped HTS armature windings, which adopts the structure with a coreless stator and a conventional squirrel-cage rotor that is aimed to lightweight and higher speed. In this paper, the saddle-shaped HTS armature windings is composed of three layers of coils, of which each layer is arranged in six along circumferential direction. Moreover, the detailed production method of the coil is illustrated. According to the electromagnetic field theory, the electromagnetic characteristic of the newly designed HTS coreless induction motor is investigated including the flux density distribution and the torque ripple under the condition of no-load and rated load. Then, based on the initial geometry model, the arrangement structure of the HTS coils is optimized and analyzed. By optimizing the rotation angle of the HTS coil layer along the circumferential direction, it is found that the magnetic field perpendicular to the tape surface in the optimized shape coils significantly decreases compared with that in the initial shape coils. In addition, it is also noticed that not only the torque ripple becomes smaller, but also the distortion of the air- gap magnetic flux density is improved. Finally, a satisfactory coils arrangement structure model is obtained, which is intended to be utilized for HTS coreless motor.