Analysis of Eddy Current Losses and Magnetization Losses in Toroidal Magnets for a 2.5 MJ HTS SMES

A SMES magnet can be operating in three different modes: charging, storing, and discharging. The eddy current losses and magnetization losses are generated during charging and discharging in the SMES system. The eddy current losses per cycle are generated mainly during discharging period because the discharging period is generally shorter that for charging. Magnetization losses per cycle are generated mainly during the charging. In this paper, we investigated a decrease in eddy current losses according to the shapes of conduction cooling plates. The cooling plate having small eddy current losses was designed by dividing and slitting. Also, the magnetization losses in the toroidal coil constructed with many pancake coils were analyzed using 3-D finite element method during the initial charging period and some discharging periods in an operating scenario for the 2.5 MJ SMES.