Electromagnetic Design Research On HTS Magnets By Bi-2223/Ag Tape

The magnet design includes the electromagnetic configuration design in order to satisfy the specific magnetic field distribution, the magnet stability, the quench protection, the magnet support system and the fabrication technology, etc.. This paper is focused on the electromagnetic designs of the high temperature superconducting (HTS) magnets, especially the optimization method and the research and development of a conduction-cooled 3.2T HTS magnet by using Bi-2223/Ag tape. It is well known that how to reduce the winding volume, improve the efficiency of superconductor utilization and lower the fabrication and operation costs of the HTS magnet is a complicate electromagnetic optimization problem. In this paper, the Genetic Algorithm (GA), the Simulated Annealing (SA) and the Sequential Quadratic Programming (SQP) used in the design of the HTS magnet were discussed and it was found that they had different advantages and limitations. So GA was improved and combined with the SA and SQP to form a hybrid genetic algorithm. This method was proved to have a strong search ability and a fast convergence speed through the test function and the optimizations of the HTS magnets. A program for the design of HTS magnet was developed by using the above optimal method. Several HTS magnets were optimized by using the program. From the optimal results, it can be seen that the optimal method plays a very important role in the design of the HTS magnet. In addition, a new optimal design method for the HTS magnet by combining the continuum discretization method with GA and SQP was studied. The method does not need an initial configuration of the magnet before the optimization. It has a particular advantage different from GA, SA and SQP. The paper also describes the research and development of a conduction-cooled 3.2T HTS magnet by using Bi-2223/Ag tape and the corresponding tests and analyses.