Heat Leakages And Losses Of Current Leads In Superconducting Wiring System

In superconducting wiring system, the current lead is one of the most important parts, which connects the superconducting power device and the room-temperature power supply, which connects the low-temperature superconducting power device and the room-temperature power supply. Just because of its great heat leakage, how to reducing heat leakage of current lead has always been one of the most crucial technology research. For high temperature superconducting (HTS) power device, the current lead can be generally divided into conventional copper current lead and binary current lead. The heat leakage from conventional current lead to liquid nitrogen depends largely on the heat transfer characteristic of current lead. Therefore, the different structure of lead has great effect on heat transfer. The new type of binary current lead includes higher temperature section (conventional current lead) and lower temperature section (HTS current lead).). There is a middle temperature point between these two sections. Because of the elimination of joule heat and low thermal conductivity in superconducting material, AC loss should be paid more attentions to. So the selection of HTS tape and structure of HTS section largely determines the lead performance.Based on the analysis of public published research achievements about HTS current lead, a new current lead design has been carried out, and the heat leakage is estimated by simulation and experiment in this paper. In details:calculated the optimal length and cross sectional area ratio (OLAR) and the minimum heat leakage of conventional current lead; proposed two kinds of heat transfer structure design; analyzed temperature field or distribution by Ansys finite element method;measured the real temperature distribution by experiment method; calculated the actual heat leakage on the basis of experimental data; proposed binary current lead structure by selecting new superconducting materials and designing new type of superconducting section structure; simulated the magnetic field by Ansys;calculated the AC loss by MATLAB.