In recent years, there has been a growing drive to develop high-temperature superconducting (HTS) rotating machines with high power density for power-based transportation applications, including aircraft, ship propulsion, and electric vehicles, where space and weight are at a premium.
However, when we designed the HTS electric machines, many parameters and coefficients of HTS electric machines were determined based on the empirical formulas and values accumulated by the predecessors.
A new approach called the self-organizing method was proposed to obtain optimized stator and rotor structures of HTS electric machines in a short time. The fully coupled electromagnetic models of a 30-kW class HTS synchronous/induction motor (HTS-ISM) with T-A formulation and H-formulation were developed to calculate the performance. The shielding current of the superconducting rotor bars in the HTS-ISM was clearly shown from the asynchronous to the synchronous state. Compared with the conventional design method, the new design method leads to an increase in power density and a decrease in torque ripple.
This work could be helpful for the quick design and analysis of future high-power density and high-efficiency HTS electric machines.

Keywords: Superconducting electric machine, Self-organizing method, Transportation applications