Stability Analysis of HTS SMES System With 6 kA Current for Accelerator

Using SMES system to realize energy compensation of large-scale accelerator is a new attempt for the application of SMES system, which is different from the application in the power-grid field (within kA level). It needs to have higher current capacity (>= 6 kA) and faster discharge rate (kA/s) to match the operating parameters of large accelerators. The high current carrying and ramping rate will cause AC loss deposition in the SMES coil, which will affect the stability of the SMES system. This paper introduces the AC loss deposition and stability analysis of 0.5 MJ SMES system with 6 kA current and maximum 1 kA/s current ramping rate. The SMES coil is wound with composite CORC cable. The multi-scale method is improved to be used on calculation of AC loss of SMES coil and the maximum AC loss heat deposition is about 6.5 W/m. Based on the AC loss heat data, the stability of the SMES coil is also studied. The minimum quench energy (MQE) is about 220.12 J. The maximum temperature rise during quench process is about 120 K, which is also acceptable for the SMES coil protection.