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The development of high-temperature superconducting (HTS) electrical machines results in applications of various fields, as they have higher efficiency and power density. Numerical modeling of superconducting electrical machines is usually performed by finite element method based their electrical behavior, and H-Formulation of the Maxwell's equations is one of the models that are used tremendously due to its high flexibility and simplicity. Axial field machine (AFM) is a machine topology with higher efficiency and power density, but with more complexity when modeling. This paper proposed a new 2D model for the superconducting AFM, where the superconducting coil is simulated with a 2D infinitely long model, this model also divides the electrical machine into two parts: the superconducting parts (HTS coils, bulks, etc.) and non-superconducting parts (e.g., conventional conductors, machine structure). This paper compares the results of H-A Formulation and T-A Formulation with this approach, which requires appropriate boundary conditions and continuity between the two regions, along with correct modeling of fixed and moving parts of the electrical machine, where the geometry of this model is based on a linear synchronous machine, which means the rotor is moving linearly instead of rotation. [ABSTRACT FROM AUTHOR]

When a superconductor is exposed to an AC magnetic field whilst carrying a constant DC transport current, a DC electrical resistance can be observed, commonly referred to as “dynamic resistance”. This dissipative effect can play a critical role in many potential high-temperature superconducting (HTS) applications, especially for the AC-field-actuated HTS switch, which is the key component in the HTS transformer-rectifier flux pump (TRFP). The characteristics of the HTS switch determine the performance and reliability of TRFP. In this paper, we report a numerical study of a new HTS switch design made of series-connected YBCO stacks. This study aims to obtain insights into the characteristics of dynamic resistance and power loss, including their relationships with the amplitude and the frequency of the AC magnetic field. The energy conversion efficiency of the HTS switch is also investigated. This work will help design a high-performance AC-field-actuated HTS switch. [ABSTRACT FROM AUTHOR]