Stability Analysis of MgB2 Coils for SMES Application Consisting of Large-Scale Rutherford Cables

MgB
₂
wires have been provided by several manufacturers, showing enough critical current (Ic) for practical applications in relatively low-field. Because the MgB
₂
has critical temperature above boiling temperature of hydrogen, dc power distribution system with low carbon emission using MgB
₂
superconducting magnetic energy storage (SMES), named advanced superconducting power conditioning system has been proposed. For the system, the MgB
₂
coil production technology obtaining 30 kJ stored energy the investigation about the SMES coil consists of 600 A, 1.7-T Rutherford-type conductors made of commercially-available MgB
₂
wires. Due to strain sensitivity before/after heat treatment for MgB
₂
production, the proper designs of the large-scale twisted conductors both in wind and react, react and wind methods are needed, choosing optimized twist pitches and cable compaction factors. To demonstrate the SMES coil performance, we have been carried out the test campaign of conductors and small prototype coils in various temperature and background field conditions. These results are used for a computer simulation for estimating full size double pancake coil performance of the system, based on the non-steady state heat conduction analysis. The calculated result seems to be a good tool for predicting coil performance for the large capacity energy storage operation.