An Improved Calculation Method for AC Losses of 30 MJ/5 MW SMES

The toroidal D-shaped high-temperature super-conducting (HTS) magnet structure offers several advantages, such as low leakage magnetic field and vertical magnetic field on the tapes, and excellent mechanical properties characterized by pure tensile electromagnetic stress. As a result, it finds wide application in large-scale magnetic, including superconducting magnetic energy storage (SMES) and magnetic confinement fusion (MCF) devices. However, the highly asymmetric three-dimensional structure impose challenges in numerical modeling and electromagnetic computations, leading to difficulties in modeling, low computational efficiency, and even computational infeasibility. The "dimension reduction inversion" method is an innovative approach for electromagnetic calculations in toroidal magnets. this paper improved upon this method and applied it to the toroidal D-shaped structure, specifically calculating the electromagnetic field and AC loss of 30MJ/5MW liquid hydrogen superconducting composite energy storage (LIQHYSMES) magnet. This research provides a feasible approach for electromagnetic computations in large-scale toroidal D-shaped HTS magnets.