Trapped Field Superconducting Electrical Machine Based on Wide 2G HTS Tapes and Its Finite Element Analysis

The development of superconducting machines has gained attention in applications requiring high power density, such as wind turbine generators and electric aircraft propulsion. The ability of superconducting materials to sustain high current densities enables the design of more compact and lightweight electric machines, improving their power‐to‐mass ratio. Trapped field superconducting machine prototypes have been constructed and tested to investigate this technology. The machine rotors were built by stacking second‐generation (2G) high‐temperature superconducting (HTS) tapes wound in the azimuthal direction over a solid ferromagnetic rotor core. The experimental results confirmed the effectiveness of this topology. In the present paper, finite element method (FEM) simulations were performed to further investigate the trapped field machine. The J–A formulation and the E–J power law were applied to represent all nonlinearities present in the ferromagnetic and superconducting materials in an effort to understand the electromagnetic behaviour of such machines. The study began by analysing how the highest possible trapped field may be achieved during the magnetisation process based on pulsed currents. The persistent current density was investigated in the 2G HTS tape stack to trap the magnetic field. Finally, the machine's performance as a generator was evaluated, and the simulated results were compared with experimental data to check the model's basic assumptions and its limitations. The findings provide valuable insights into the magnetisation behaviour of superconducting rotors and the induced voltage characteristics, contributing to the advancement of superconducting stacked rotors for high‐power‐density applications.