A full-wave HTS flux pump using a feedback control system

Transformer-rectifier flux pumps are DC superconducting power supplies capable of charging superconducting magnets to high currents and stored magnetic energies. Here, we demonstrate a full-wave superconducting flux pump assembled from high-temperature superconducting (HTS) wire that utilizes superconducting switches controlled by applied magnetic field. A negative DC offset occurs in the superconducting secondary of the circuit during operation which is related to the output load current. A feedback control system is proposed and demonstrated to account for the negative DC offset. Increasing the primary current proportional to the load current during operation allowed for the maximum output of the flux pump to be increased from 35 A to more than 275 A. These results are reproduced using a coupled electrical- and magnetic–circuit model formulated in the MATLAB Simulink® package.