AC Loss Analysis on Coated Conductors at different Sinusoidal Frequencies for Electric Propulsion Applications

Abstract

Abstract Superconducting magnets are one of the superior contenders in achieving the targets of electric aircraft industry successfully as they have very high power densities compared to other battery storage systems. Many aviation research agencies are looking at superconducting magnets as one of the alternate in replacing the conventional jet engines completely (electric aircrafts) or partially (hybrid aircrafts). National Aeronautics and Space Administration (NASA) and Air Force Research Laboratory (AFRL), USA has reported that high temperature superconducting magnets possesses higher specific energies (Wh/kg) and have infinite number of recharge cycles compared to other storage technologies employed for energy requirements. The other advantage of using such magnets is that there will be no hazardous disposals like batteries which lower the overall pollution. Superconducting magnets are DC operated systems however during charging or discharging transient behaviour of current results in the losses which would further ends up with heat generation. Heat generation during charging or discharging period would cause quenching of the superconductor due to sudden temperature rise. In this work, electromagnetic analysis on superconducting magnet having capacity of 1 MJ has been performed where a 2D numerical model is developed using H-formulations in order to estimate the AC losses for a high temperature superconducting tape manufactured by SuperPower (SCS 12050) having 330 A critical current at 77 K. AC current having different load factors has been fed through the stacked tapes at 50 Hz, 60 Hz and 70 Hz frequency and AC losses have been evaluated. It has been found that at higher frequencies the AC losses are found to be larger than lower frequencies. Overcritical currents have been found in the current density distribution due to the application of E-J relationship for the homogeneous 2D numerical model.