Study On The Energization Characteristics Of A New Type Of High Temperature Superconducting Square Wire Under Different Conditions

Superconductivity has been the focus of international physicists,and high temperature superconducting wires have broad prospects and applications.In order to make the high temperature superconducting wire have higher performance,a new type of high temperature superconducting square wire is obtained by narrowing the second-generation high temperature superconducting wire YBCO.When the superconducting wire is energized,the characteristics of the superconducting wire will be affected by factors such as the self-field environment and the size and direction of the external magnetic field.Therefore,this paper chooses to study the energization characteristics of the 4s+2c new high temperature superconducting square wire,and study the influence of different conditions on the critical current characteristics and AC loss characteristics of the new square wire.First,the critical current characteristics of the new high temperature superconducting square wire of 4s+2c are tested and analyzed.Since the superconducting wire is applied in the actual superconducting cable,it will not keep the parallel state all the time,and deformation such as twisting will occur.Therefore,for the two different new square wire structures: parallel wire and twisted wire,the critical current is calculated separately.To measure,build a critical current measurement system for 4s+2c new high temperature superconducting square wire in the field environment and the external field environment.Secondly,the influence of the critical current of 4s + 2c parallel wire and twisted twisted wire from different magnetic induction strength and different magnetic field angles in the independent field environment and external field environment is studied,and the critical current characteristics of the new 4s + 2c square wire with two different structures are compared.Finally,the parallel wires and twisted wires of the new high temperature superconducting square wire of 4s+2c are carried out by COMSOL Multiphysics software for two-dimensional simulation calculation and three-dimensional simulation calculation to study the AC loss characteristics.In order to reduce the calculation time,a homogenization model is proposed and compared with the complete model to verify the feasibility of the homogenization model.According to the application of high temperature superconducting wires in actual cables,the simulation model construction and AC loss research of multiple twisted wires are carried out.The experimental results show that the 4s+2c square wire exhibits good superconductivity in the field environment in the study of the critical current characteristics of the 4s+2c new high temperature superconducting square wire,and the dependence of the parallel wire on the magnetic field angle in the external field environment is greater than Twisted wire is also more anisotropic than twisted wire.The twisting of the wire can reduce the influence of the external magnetic field on the critical current characteristics.The law that the critical current of 4s+2c square wire changes with different magnetic field conditions is obtained.In terms of simulation research on AC loss characteristics,in 2D and3 D simulation calculations,the simulation results under the complete model are basically consistent with those under the homogenized model.The homogenized model is reliable and the simulation calculation time is reduced.50% or so.The AC loss of twisted wire is lower than that of parallel wire.