Mechanical behavior analysis of a 1 MJ SMES magnet

For several decades, researches and developments on superconducting magnetic energy storage (SMES) system have been carried out actively world wide for efficient electric power management. A large bore NbTi superconducting magnet with liquid helium bath cooling has been developed in the Institute of Electrical Engineering, Chinese Academy of Sciences (IEE, CAS), which can be demonstrated as a micro-sized 1 MJ SMES. Even though the superconducting magnet is designed optimally in respect to the preload and electromagnetic force, consideration of mechanical integrity due to stress must not be neglected for the stable operation of the SMES system. Therefore, in order to study the mechanical behavior of the SMES magnet, a two-dimensional axisymmetric finite element analysis was performed. In the paper, the details of the magnet design, FEA model and results of the mechanical behavior analysis are presented.