Design Optimization of HTS Field Coils for High Power Density Motors Based on Continuum Sensitivity Analysis

This study proposes an optimization method for designing HTS field coils for high power density motors based on continuum sensitivity analysis. The continuum sensitivity of a superconducting system represents the gradient of the objective function with respect to the superconducting material shape, taking the critical current characteristics into account. The continuum sensitivity was coupled with the level set method through the design velocity field, and the design of the HTS field coil was performed by solving the level set equation. The applicability of the proposed method was verified by designing a 200 kW HTS motor to maximize the torque density. The design optimization provided an optimal solution through the evolution of the topology and shape of the HTS field coil. The optimized geometry was employed to design field coils consisting of racetrack coils wound with HTS tape. Finally, further designs with different cross-sectional areas of the field coils demonstrated that the proposed method can design HTS motors with minimal HTS tape for a given rated power and motor size.