The Refined T-A Formulation for HTS No-Insulation Coils Considering Conductor Thickness

The T-A formulation of Maxwell’s equations is widely employed for modeling high temperature superconducting (HTS) coated conductors due to its high computational speed. However, when considering the thickness of the superconducting layer, the traditional T-A formulation still faces challenges in terms of low accuracy and poor convergence, particularly along the thickness direction, necessitating further refinement. In this article, a refined T-A formulation for no-insulation (NI) HTS coil considering the conductor thickness is introduced to address this limitation, and the corresponding homogeneous model is developed. The model’s accuracy is improved by applying Neumann boundary conditions and validated using both simulations and experimental results. Its advantages in calculating the distribution of screening current along the thickness direction are demonstrated in case studies, including the charging process and applying an axial shaking field to the NI coil. This refined method improves the accuracy and convergence of the T-A formulation, broadening its application to the transient analysis of HTS coil.