Study on AC Loss and Temperature Change of Energy Storage Magnet Under Different Working Conditions

When a superconducting magnetic energy storage (SMES) device exchanges energy with the outside world, the superconducting magnet will be in the environment of dynamic transformation of the current and magnetic field, and the AC loss and temperature change caused by this process cannot be ignored, which will seriously affect the long-term stable operation of the magnet. Given the above problems, this paper established an electromagnetic thermal coupling model, taking into account the loss heat source of the magnet and the external environment commutation and other conditions, calculated the loss changes of the magnet under different working conditions, explored the temperature change law, obtained the temperature distribution, and provided a reference for the design of the cooling guide system. The $\Gamma $-shaped flux diverters (FDs) were introduced to reduce the loss of the magnet. The results show that the loss is lower when the steady state reference current is maintained at 60% of the critical current. FDs have a more significant suppression effect on the losses generated by dynamic alternating current than the steady-state current