Effect of Dynamic Resistance on AC Loss in Stacked Superconducting Tapes

High temperature superconductors (HTS) are promising candidate conductors for multiple applications, such as superconducting magnets and electric machines. However, these superconductors are normally faced with significant AC loss under a certain alternating magnetic field. Dynamic resistance occurs in a superconductor which carries DC current and experiences an AC magnetic field that exceeds the threshold value. In order to understand the mechanisms and magnitudes of AC loss and dynamic resistance for each tape which is stacked in z-arrays, the equation of dynamic resistance for stacked HTS wires in a perpendicular field was modified based on the formula for a single coated conductor. Analytical predictions were compared with experimental results. It is shown that analytical expressions modified by the external susceptibility and Kim model are available for predicting the dynamic resistance of stacked superconducting tapes.