AC losses of HTS coils carrying transport current

In the paper we report the experimental results for ac losses in HTS coil carrying ac transport current. The tests of ac losses mere performed by the electrical method at 77 K and 4.2 K. The HTS tape consists of 55 multi-filamentary silver-sheathed BSCCO 2223 tape without twisting. The sample coil was made by the React and Wind method using insulated tape conductor. The coil has the inner diameter of 46 mm, outer diameter of 87 mm, height of 14.5 mm, and the number of turns is 300 turns. The measured ac losses were compared with the conventional theory based on the critical state model. In the region of low transport current, the theoretical results agreed well the experimental results. We also investigated the distribution of the sc losses in the coil to study the effects of magnetic field distribution on ac losses.