High-output density partial superconducting motors for aviation systems

Abstract

Abstract This paper describes electromagnetic design of partial superconducting motors (PSCMs) using YBCO field coils and copper armature windings. It has simpler structure than that of fully superconducting motors (FSCMs), which have superconducting field/armature windings. The target output density is set over 16 kW/kg. For the first step, we designed the 3.0-, 5.0- and 9.0-MW superconducting motors by means of analytical equations. We used genetic algorithm to find the proper conditions, including magnetic flux density amplitude, machine diameter and rotation speed, for our optimal machine structure. The results show that the 5.0-and 9.0- MW PSCMs could reach over 16 kW/kg and in some 9.0-MW cases, we recognized that the output density of 26 kW/kg had been almost attained. After the optimal design, FEM analysis was conducted for some design results of the 5.0- and 9.0- MW PSCMs, in order to evaluate motor losses, copper and iron loss, as well as maximum magnetic flux density and motor output. The motor efficiency could reach over 98% in all the FEM design cases. Also, the output density values were almost the same as those in the design cases with analytical equations. These analytical and FEM design results refer that over 16 kW/kg is possible with PSCMs; if we should obtain the output density of over 20 kW/kg with the PSCM structure, however, the 9.0-MW PSCMs are indispensable.