AC losses in the development of superconducting magnetic energy storage devices

摘要

AC losses are inevitable to be considered for effective design of Superconducting Magnetic Energy Storage (SMES) devices using High Temperature Superconductors. Various analytical techniques are available to estimate these AC losses however not sufficient to accurately predict the same. Hence, computational methods are being widely used in the prediction of AC losses as the experimental techniques are complicated to be implemented. YBCO (Tc = 90 K @ 0T) and BSCCO (Tc = 110 K @ 0T) are generally used in the construction of SMES. However, the critical temperature reduces as the external magnetic field is experienced by the tapes increases giving lower temperature margin for cooling purposes. In the present work, Computational Electrodynamics is used to predict the AC losses in Second Generation HTS tapes used in constructing the SMES. These losses which are dissipated as heat must be balanced by the cooling the requirements. The effect of external magnetic field on the degradation of critical current is examined. Finite Difference Time Domain approach is used for discretization of governing equations in solving for the AC losses. Further, electric field distribution in coated conductors due to the applied magnetic field is investigated. Hence, the results of the present analysis guide the thermohydraulic design of SMES devices.