Study on Winding Process and Performance Test of High Temperature Superconducting Coil

In this paper,the winding process of a large high temperature superconducting coil was introduced,and the best joint welding process was obtained by repeated experiments,which meets the requirement of stable operation of superconducting coils.The current carrying capacity of high temperature superconducting(HTS)strips under the condition of radial bending of strain fatigue,as well as V-I curve of HTS coils,were measured in self-field at the temperature of 77 K.The result indicates:when the bending times were equal or less than 10,the current carrying capacity of HTS strips was unchanged.HTS coils winded with the process in this paper have good performance,and the critical current measured in self-field at 77 K is 168.12 amperes.The best welding result was obtained when welding temperature is 439 K,overlapping length 4 cm and Sn63Pb was employed as solder.