Research And Calculation Of AC Loss In YBCO High Temperature Superconducting Conductor

High temperature superconducting (HTS) conductor as a current carrying conductorwhich is used in large capacity, low loss transmission has an extensive prospect because ofsmall bulk, low loss and high carrying capacity. But AC loss as a critical factor is limited thecommercialization process of superconducting conductor, AC loss directly affects the price ofthe entire cooling system and the costs of operation, the superiority of the HTS conductor iswell reflected only when the AC loss is low to the extent. So the accurate calculation andmeasurement of the AC losses in HTS conductor is very significant.The study is investigated the background based on the calculation of the AC losses inHTS conductor, identified YBCO HTS conductor as the main research object. We measure theAC losses in YBCO HTS conductor and single-layer conductor by use of electricalmeasurement, compared with BSCCO and YBCO-NiW. The results show that the measuredAC losses in YBCO conductor and BSCCO conductor are in good agreement with thenumerically calculated losses based on the Norris equation, while the measured AC losses inYBCO-NiW conductor are not in accordance with the Norris equation because of magneticsubstrates and the method of measurement and calculation.Using the finite element software COMSOL Multiphysics is used to simulatetwo-dimensional finite element calculation model based on different arrangements anddifferent types of HTS conductor, the AC losses in HTS conductor are calculated based onfinite element numerical model, and compared with the experimental and theoretical results.The results show that the AC losses under cylindrical arrangement are the least, the self-fieldlosses of the BSCCO, YBCO, and YBCO-NiW wires are identical to numerical results. Thenon-magnetic materials in HTS wires do not have an effect on their AC losses. In addition, itis confirmed that the YBCO-NiW wire is asymmetric not only geometry structure but alsomagnetic field distribution surrounding the wire due to the magnetic substrate, NiW layer.Especially for the YN conductor, the measured AC losses are independent on the voltage-leadarrangement. And the AC losses of the YBCO and YBCO-NiW conductors, which include1μm thickness of the superconductor layer, are quite different from the numerical results.Finally, the AC losses of the four conductors are similar regardless of the different substratesand the thickness of the superconductor layers.