A Hybrid Model for Studying AC Losses in HTS Tapes of a Linear Machine

In a linear machine, the DC HTS (High-Temperature Superconductors) coils, placed in the stator, are subjected to a spatially non-uniform and time-varying external magnetic field originating from the AC coils in the mover while carrying a transport current. Under these conditions, AC losses are generated in the superconducting coils. In this paper, a two-dimensional hybrid method is proposed to calculate the above mentioned AC losses, combining two existing approaches: the harmonic modeling technique and the integral method. The harmonic modeling technique is a semi-analytical method used to predict the spatially non-uniform and time-varying external magnetic field generated by the AC coils within the superconducting region. The integral method is a numerical approach used to calculate the AC losses induced in the superconducting coils in the stator by the external magnetic field, determined by the harmonic modeling technique. The developed method is validated by COMSOL software with the T-A formulation. The composition of both models developed for the superconducting linear machine significantly reduces the simulation time due to their efficient computational performance compared to numerical simulations.