AC losses in first and second generation high T/sub c/ tapes and MgB/sub 2/ tapes

Technical and economical assessments for future power applications of High T/sub c/ superconductivity require the evaluation and comparison of AC losses in first and second generation high T/sub c/ tapes. An electrical and a thermometric method were developed and used to measure transport AC loss in OPIT Bi-2223/Ag tapes, Y-123 coated conductors and in new MgB/sub 2/-based superconductors, simulating the AC conditions typical of power devices. The results were compared with analytical models for AC losses calculation. The effect of the magnetic substrates used in coated conductors was also investigated and a simple calculation model was proposed.