Analytical Calculation of Mutual Inductance of D-Shaped Coils Applied to High-Temperature Superconducting Magnet

D-shaped coils, which are applied to large toroidal HTS-SMES magnets, can reduce the non-uniform tension and large bending moment caused by the structure of toroidal magnets and decrease the stress of the coil section. It is vital to accurately calculate the self-inductance and mutual inductance parameters for all the turns and coils in analyzing the transient response of HTS-SMES magnets. In this paper, an analytical calculation method for calculating mutual inductance parameters between D-shaped coils is presented, to address the potential challenges of meshing and long time-consuming computations in the 3D finite element method (FEM) model. The calculation results are compared with mutual inductance obtained by the FEM. The results show that the proposed analytical method can calculate the mutual inductance of D-shaped coils quickly and effectively. Moreover, the mutual inductance of the model, which has a large width/height ratio, can also be calculated. Finally, the influences of the width and thickness of tapes and the distance between coils on the mutual inductance between D-shaped coils are studied.