Waveform Control Pulsed Magnetization of GdBaCuO Bulk Using Negative Feedback at 60 K

Abstract

The practical use of high-temperature superconducting bulk electric rotating machines is limited, despite their increased power densities over permanent magnet machines, by the magnetization process of the bulks. A fast and effective magnetization process is needed to promote the practical application of superconducting machines. This is why we developed a method for magnetizing bulk superconductors and trapping high magnetic flux density using a single pulsed field magnetization (PFM). The method of magnetization of the superconducting bulk magnet by controlling the applied magnetic field has been tested previously at 77 K and 70 K. We tried during this study to trap high magnetic flux density in a GdBaCuO bulk at 60 K, to confirm that the method is effective at a lower temperature. Moreover, we tried to improve the method by using negative feedback of the magnetic flux density on the growth sector, to control the chopping of the current flowing through the magnetizing coils. We managed to reduce the temperature rise during the pulse by 10 K compared to a passive PFM and trapped a maximum of 2.17 T in the center of the bulk sample, the improvements compared to passive PFM at 60 K are remarkable.