Numerical Study of Optimization Design of High Temperature Superconducting Field Winding in 20 MW Synchronous Motor for Ship Propulsion

This paper presents the optimization study of the field winding structure of the 20 MW-class HTS motor for the electric ship propulsion based on the minimization of the flux flow loss. The examples of the optimized shape of the HTS field pole coils obtained by the numerical analysis are presented. By optimizing the cross section of the field pole coil, it is found that the magnetic field perpendicular to the tape surface in the optimized shape coil significantly decreases compared with that in the rectangular shape base coil. As the results of the reduction of the perpendicular magnetic field, it is shown that the flux flow loss remarkably decreases. It is also pointed that the necessary length of the HTS tape for the optimized shape coil increases.