Experimental and Analytical Study on Torque Density Maximization of High Temperature Superconducting Induction/Synchronous Motor

This paper reports on torque density maximization and overload tolerance of a high-temperature superconducting induction/synchronous motor (HTS-ISM), which has been aiming to next generation transportation equipment (bus, truck, electric vehicle, etc.). That is, overload characteristics of the HTS-ISM is explained and demonstrated through analysis and experiments. It is shown that the prototype shows overload (slip) output at 2 times as large as the rated synchronous one (20 kW), and then such characteristics can be reproduced by means of 2D finite element analysis, in which the contact resistance of rotor windings is utilized as a fitting parameter. Furthermore, high torque test at 600 rpm is also carried out and discussed. This result could be applied to the optimal design of the HTS-ISM that possesses the overload tolerance.