An HTS flux pump operated by directly driving a superconductor into flux flow region in the E– J curve

High- T _c superconducting (HTS) flux pumps are capable of compensating the persistent current decay in HTS magnets without electrical contact. In this paper, following work on a low- T _c superconducting self-switching flux pump, we propose a new HTS flux pump by directly driving a high- T _c superconductor into the flux flow region in the E– J curve. The flux pump consists of a transformer which has a superconducting secondary winding shorted by an YBCO-coated conductor bridge. A high alternating current with a much higher positive peak value than the negative peak value is induced in the secondary winding. The current always drives the bridge superconductor into the flux flow region only at around its positive peak value, thus resulting in flux pumping. The proposed flux pump is much simpler than existing HTS flux pumps. (paper)