An optimization method for design of SMES coils using YBCO tape

Recently, the properties of high temperature superconducting (HTS) tapes have been in advance and HTS magnets have been constructed and demonstrated. However, the HTS tapes have thermal different characteristics compared with the low temperature superconducting (LTS) wires. Moreover, Bi2223/Ag tapes and YBCO coated conductors have the different properties about the dependence on the degree of external magnetic field. Therefore it is necessary to consider these characteristics of HTS tapes at magnet design stage. We proposed an optimal design method for superconducting coils using Bi2223/Ag tapes. And the proposed configuration is optimized by using the simulated annealing (SA), which is one of the optimization algorithms, under a lot of constraints such as B-I characteristic, storage energy, and so on. The details of the optimization method and an example of its application to SMES coils (72 MJ) using YBCO coated conductors are shown.