Waveform Control Pulse Magnetization of GdBaCuO Bulk Near Operating Temperature of Our Superconducting Rotating Machine

We have tested our waveform control pulse magnetization with negative feedback (WCPM-NFB) method on a GdBa 2 C 3 O 7-δ (GdBaCuO) high temperature superconducting (HTS) bulk sample, near operating temperatures of superconducting machines. This advanced single pulse field magnetization (PFM) method was demonstrated to significantly increase the trapped magnetic flux density in the center of the bulk compared to more conventional PFM techniques. The WCPM-NFB method has been further enhanced by modifying the control of the applied pulsed magnetic field. The aim was to adapt the control method to make use of the flux jump in a more efficient way while limiting the heat generation in the bulk. The target magnetic flux density of the PID controller was changed during the pulsed magnetization, allowing the applied magnetic field to be adapted consequently to the change of condition inside the bulk due to the flux jump. A magnetic flux density of about 3 T has been trapped at 50 K in a single pulse using our improved WCPM-NFB method.