Experimental Study On Critical Current Characteristics Of The 2G HTS Wire Under External Magnetic Field

When used in superconducting magnets or superconducting power devices,superconducting wires will always be exposed to external magnetic fields of AC and DC to varying degrees.The external magnetic field will affect its critical current and AC loss characteristics,especially the magnetic field perpendicular to the surface of the superconducting wire..In order to reduce the effect of external magnetic field and temperature changes on the electromagnetic characteristics of the superconducting wire,the method of production of the low-temperature superconducting wire mainly adopts twistedtwisted wire core and wire transposition.However,due to the material properties of the superconducting tape in the superconducting wire,the width of the 2G HTS tape in the current application is more than 4mm,and the above method cannot be flexibly utilized.If the width of the 2G HTS tape can be narrowed to 1mm or less and then twisted,the electromagnetic properties of the superconducting wire can be greatly improved.The topic will focus on the external magnetic field environment and conduct a systematic study on the critical current of a new HTS square wire.In this study,a critical current test system was designed and built according to the critical current test principle of HTS tapes in the external field.Mainly to study the variation of critical current at different magnetic induction(0T-1.2T)and different angles(0°-360°)for 1mm wide HTS square wire under different structures,and compared with 4mm and 1mm wide HTS tapes.The influence of magnetic field on the critical current of HTS square wire was analyzed.Furthermore,the critical current variation at different magnetic induction(0T-0.25T)and different angles(0°,45°,and 90°)of HTS square wire of twisted structure was further studied.The subject of this study is a square wire based on 1mm width 2G HTS tape,first proposed by Shanghai Jiaotong University in 2016,The technology already has relevant experimental conditions such as material preparation,critical current and AC loss testing.In this project,the experimental results show that the critical current characteristics of the HTS square wire change under different magnetic field conditions.The results of this project provide a data basis for the simulation of the HTS square wire,and provide valuable reference for the application of the HTS square wire.