Modifying the Pulsed-Field-Magnetization Technique for HTS Bulks in Electrical Machines Without Magnetic Field Sensors

This paper studies the high-temperature superconductor (HTS) YBCO and GdBCO bulks pulse-field magnetization (PFM) in loco, that is, when inserted in an electric machine's magnetic circuit. The PFM typically uses cryogenic hall sensors to monitor the magnetization process. However, to install cryogenic hall sensors in the magnetic excitation circuit of an electrical machine may increase the air gap and increase the machine cost. To surpass that, this paper presents an indirect technique capable of monitoring the superconductor magnetization process through the applied pulse voltage and associated electric current transient waveform. Last, different levels and the numbers of pulses were applied to magnetize the HTS bulks inside the magnetic circuit to analyze the resultant trapped magnetic field. Differences between the YBCO and GdBCO are highlighted and discussed.