Flux dynamic behavior inside HTS bulks under rotating magnetic field

Melt texturing large-grain HTS materials has evolved in the last few years into a technology capable of producing large quantities of high-performance superconducting bulk materials. Such materials are used for developing novel engineering devices, such as high-speed bearing, flywheel system and motor. In these systems, however, it is very possible to generate rotating magnetic fields with the frequency higher than 50 Hz due to various inhomogeneities. Hence, the experimental investigation was presented on the change of the levitation force and the trapped-flux response of HTS bulks exposed to the rotating magnetic fields with different frequencies. Meanwhile, the experimental phenomena were qualitatively analyzed and discussed in this paper, based on HTS flux dynamics.